Biodiversity of saproxylic beetles of pine forests in

Saproxylic beetles in Europe: monitoring, biology and conservation, p. 7–10 GDK 145.76+907

The IUCN European Red List of Saproxylic Beetles – working towards a European Saproxylic Beetle Conservation Strategy Keith N. A. Alexander1 Abstract The publication of the European Red List of Saproxylic Beetles in 2010 raises this fauna to a new level in conservation administration across Europe. It is important that specialists in saproxylic ecology and conservation now build on this new initiative. A European Saproxylic Beetle Red List Group has now been initiated within IUCN and the first task is to develop a new conservation action strategy. This paper suggests some of the key issues and explores the contexts and future planning.

Key words: European Red List, saproxylic beetles, conservation strategy, threatened species

1. Introduction Following publication of the European Red List of Saproxylic Beetles (NIETO / ALEXANDER 2010), the Invertebrate Conservation Sub-Committee (ICSC) of the Species Survival Commission (IUCN) has approved – in September 2010 - the establishment of a European Saproxylic Beetle Red List Group under the aegis of the IUCN. This now provides a mechanism for the development of saproxylic beetle conservation in Europe. Unlike a full IUCN Specialist Group, a Red List Group has great flexibility in how it operates - a full Specialist Group would operate within a formal legal agreement with IUCN. The author has been appointed as Specialist Adviser, to act as the focal point between the Group and the ICSC.

2. Maintenance and development of the European Red List A primary focus of the Red List Group will of course be the expansion and up-dating of the current European Red List of Saproxylic Beetles and the development of fuller taxonomic coverage – it currently consists of full coverage of 15 families plus a selection from a further 5 families. The IUCN operates a review cycle for Red Lists, with a minor review after five years and a more detailed one every 10 years. These enable any newly available information to be incorporated into the published Red List, and for the threat categories to be kept as up-to-date as possible. The IUCN have been in discussion with the EU about funding for the taxonomic completion of the Red List as part of the reporting process, and it is hoped than the second and final phase will be possible within a few years. 1

3. Development of a European Conservation Strategy The Red List Group will also provide a framework for broadening activities beyond the Red List assessments. A priority area for action is the development of a European Saproxylic Beetle Conservation Strategy. Speight (1989) and Haslett (2007), together with the proceedings of the various European saproxylic conferences (BOWEN 2003, MASON et al. 2003, BARCLAY / TELNOV 2005, VALLAURI et al. 2005, VIGNON / ASMODÉ 2008, BUSE et al. 2009), contain much of the background material needed for the Strategy. The Strategy will need to address the following topics: ● improvements in species data quality, particularly population size, trends and detailed threat analysis for Threatened and Near Threatened species; ● identification of priority areas for other ecological research, such as the relationships between the beetles and tree ecology; ● promotion of improvements in conservation management, within the Natura 2000 Network, and beyond: - site management actually targeted at saproxylic conservation; - site and species condition monitoring; ● exploration of the scope for landscape scale conservation of saproxylic beetles; ● provision of relevant information to site managers, conservation professionals, and the general public through as wide a variety of media as possible.

dr. K. N. A. A., Ecological consultant, 59 Sweetbrier Lane, Heavitree, Exeter EX1 3AQ, United Kingdom; [email protected]

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Saproxylic beetles in Europe: monitoring, biology and conservation

4. Improvements in species data quality The Red List species status assessment process has revealed some important knowledge gaps: ● the Data Deficient category contains 122 species (28%) where it was felt that not enough knowledge was available to evaluate their risk of extinction; - these will include potential ‘Threatened’ and ‘Near Threatened’ species as well as ‘Least Concern’ ● the population trend for 249 species (57%) remains unknown There is therefore a clear need for improved monitoring, especially of ‘Threatened’ and ‘Near Threatened’ species. Little evidence was found during the data gathering process of attempts to quantify populations, and yet without reliable estimates it will be impossible to monitor change, identify conservation priorities, and assess the success of conservation measures.

5. Priority areas for ecological research The conservation of saproxylic beetles requires considerable knowledge about their ecology and especially their population dynamics, but – with a few exceptions – little is known about most species. It is the author’s view that the relationship between these beetles and their host trees is the largest and most important gap in knowledge. Alexander (2008) points out that the key factors affecting the presence or absence of saproxylic beetles are: ● the total numbers of trees, impacting on beetle population viability; ● the age structure of the tree population, impacting on the cycle of availability of trees in suitable condition for the beetle; ● the density of trees, which is important in determining the proportion of open-grown trees with well– developed lateral branching and sun-warmed trunks – features known to be of considerable importance for many saproxylic beetles; ● the history of the above on the site – tree populations fluctuate over time (naturally or through the activities of people) and local extinctions of the beetles may occur during the low periods but not re-colonise during the high periods. This is a multidisciplinary topic involving tree biologists, population biologists and mycologists as well as invertebrate ecologists, which is perhaps why it has not been tackled by saproxylic beetle ecologists.

6. Improvements in conservation management It is very pertinent that the Council of Europe’s Recommendation No R “88” 10 of the Committee of Ministers to member states on the protection of saproxylic organisms and their biotopes and which was formally adopted on 13 June 1988, includes as Recommendation 4: manage protected forests according to local conditions and in such a way as to maintain their saproxylic fauna and flora. The full text is recorded in Speight (1989). The Natura 2000 Network appears to be failing saproxylic beetles. It is not only too site-based, but the management of those sites is too dominated by vegetation ecologists and their unproven hypotheses of ‘natural processes’. The ‘Strict Forest Reserve’ concept is especially damaging as it is based on non–intervention management. The role of large herbivores in maintaining the structural dynamic of the tree population (VERA 2000) is rarely appreciated. The number of large veteran trees is declining in these sites – especially open-grown trees – and new generations of suitable trees are not developing – the rare and threatened saproxylic beetles are doomed to extinction under a system which claims to be primarily about conservation. The current conception of ‘Strict Forest Reserves’ is actually very damaging as livestock grazing is deemed ‘un-natural’ and yet natural large herbivore populations have been decimated by people and natural grazing is no longer feasible. A good example is the Hasbruch in Lower Saxony, Germany. This former historic wood pasture, with its ancient trees and rich saproxylic beetle fauna, and the historic cultural importance of its medieval working landscape, now has large herbivores excluded. The consequence has been extensive secondary growth of trees and shrubs, and especially shade-tolerant species, which are now beginning to outcompete the veteran trees for light. Trees killed by this canopy closure are now widely present, and the remaining live ancient trees are seriously threatened. The same situation can be found elsewhere across Europe in other famous Natura 2000 sites, eg Fontainebleau Forest in France and Bialowieza Forest, Poland.

7. Landscape scale conservation With the famous sites undergoing such damaging vegetation change what future do the threatened saproxylic beetles have in the wider landscape? Many of these beetles are well-known to be relatively slow colonists; they tend to be species which do not travel far as adults and are unable to cross large expanses of unsuitable habitat. Mobility within the wider landscape is therefore very constrained. If conservation is to improve the robustness of the relict populations of the threatened saproxylic beetles then it requires a landscape approach. Attention needs to be given

Aleksander, K. N. A.: The IUCN European Red List of Saproxylic Beetles – working towards ... to conservation of veteran trees throughout the landscape. While historic wood pastures have largely disappeared from the European landscape, veteran trees may still be widely found in traditional orchards, historic avenues, and field and boundary trees. These are all land– use types which promote open–grown trees and thereby favour the development of veteran trees with their wide variety of saproxylic habitats (ALEXANDER et al. 2003, ALEXANDER 2008). In many parts of Europe, rare and threatened saproxylic beetles are well-known to thrive in such landscapes. Osmoderma eremita, for example, is known as much from such situations as old forests – in veteran willows along field boundaries in Slovenia, in traditional orchards and chestnut groves in France, and in roadside avenues in Latvia. The great difficulty in conserving such species in the wider landscape is to maintain the viability of the beetle populations in such dispersed tree landscapes. Attention needs to be given to the population dynamics of the host trees as well as the beetles, to ensure that sufficient trees are developing for the longterm continuity of veteran trees. In the UK there are large projects under way to document veteran trees (Woodland Trust and Ancient Tree Forum) and traditional orchards (People’s Trust for Endangered Species) throughout the landscape, and to encourage local people to appreciate and conserve these important features of the cultural landscape. It has proved much easier to enthuse the general public about their tree heritage than their beetle heritage, and yet conserving the trees automatically conserves the beetles. This clearly is a successful and practical way forwards for the conservation of saproxylic beetles through awareness raising of tree conservation issues.

8. Provision of information The work of the Ancient Tree Hunt (ATH) in the UK has clearly shown that encouraging the general public to take an active interest in the trees in their local landscapes has considerable benefits in terms of saproxylic beetle conservation. The ATH used a wide variety of media to contact and engage people, including a dedicated website with links to related sites, a Facebook page, Twitter, blogs, publication of a series of leaflets, posters, and public talks. The project was featured on national television as well as locally. There is a similar requirement to engage with site managers and other conservation professionals, to share experience of good and bad practice, to make specialist publications more accessible, etc, using a wide variety of media.

9. Conclusion and the way forwards A European Saproxylic Beetle Conservation Strategy needs to be developed and promoted among conservation

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professionals in order to encourage good practice throughout European landscapes. The plan at the moment is to form a small working group of key activists, to develop a working strategy document, and to keep the wider network of saproxylic beetle specialists in touch through the regular Symposia and Workshops, and the e-mail group on [email protected]. The working draft will be circulated via the e-group to enable as many specialists as possible to have the opportunity of commenting and making suggestions for improvements. Once a final document has been agreed then it will be presented to the IUCN and – with their approval – promoted through the European conservation literature. Direct targeting will undoubtedly be needed in order to draw attention to key problem areas, eg with the Natura 2000 Network. It is hoped that the Strategy document will provide a good framework for conservation action.

10. References ALEXANDER, K. N. A. 2008.Tree biology and saproxylic Coleoptera: issues of definitions and conservation language. Pp 9-14 in VIGNON, V. / ASMODÉ, J.-F. (eds) Proceedings of the 4th Symposium and workshop on the conservation of saproxylic beetles, held in Vivoin, Sarthe Department – France, 27-29 June 2006. Rev. Ėcol. (Terre Vie), suppt. 10. ALEXANDER, K. N. A. / SMITH, M. / STIVEN, R. / SANDERSON, N. 2003. Defining ‘old growth’ in the UK context. English Nature Research Reports No. 494, 54 pp. BARCLAY, M. V. L. / TELNOV, D. (Eds.) 2005. Proceedings of the 3rd Symposium and Workshop on the Conservation of Saproxylic Beetles, Riga, Latvia, 07th – 11th July, 2004. Latvijas entomologs, Supplementum VI, 125 pp. BOWEN, C. P. (ed.) 2003. Proceedings of the second panEuropean conference on Saproxylic Beetles held at Royal Holloway, University of London, June 2002. London: People’s Trust for Endangered Species, 77 pp. BUSE, J. / ALEXANDER, K. N. A. / RANIUS, T. / ASSMANN, T. 2009. Saproxylic Beetles – their role and diversity in European woodland and tree habitats. Proceedings of the 5th Symposium and Workshop on the Conservation of Saproxylic Beetles. Sofia: Pensoft, 235 pp. HASLETT, J. R. 2007. European Strategy for the conservation of invertebrates. Nature and environment, No. 145. Strasbourg: Council of Europe, 84 pp. MASON, F. / NARDI, G. / TISATO, M. (eds) 2003. Proceedings of the International Symposium “Dead wood: a key to biodiversity”, Mantova, May 29th – 31st 2003. Sherwood 95, Suppl. 2, 100 pp. NIETO, A. / ALEXANDER, K. N. A. 2010.European Red List of Saproxylic Beetles. Luxembourg: Publications Office of the European Union, 45 pp. SPEIGHT, M. C. D. 1989. Saproxylic invertebrates and their conservation. Nature and Environment Series, No. 42. Strasbourg: Council of Europe, 79 pp. VALLAURI, D. / ANDRĖ, J. / DODELIN, B. / EYNARDMACHET, R. / RAMBAUD, D. (eds) 2005. Bois mort et à cavités. Paris: Lavoisier. VERA, F. W. M. 2000. Grazing Ecology and Forest History.

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Saproxylic beetles in Europe: monitoring, biology and conservation Wallingford: CABI Publishing, 506 pp.

VIGNON, V. / ASMODĖ, J.-F. (eds.) 2008. Proceedings of the 4th Symposium and Workshop on the Conservation of Saproxylic Beetles, held in Vivoin, Sarthe Department – France 27-29 June 2006. Revue D’Ėcologie (Terre Vie) Supplément 10, 159 pp.

Saproxylic beetles in Europe: monitoring, biology and conservation p. 11–16 GDK 145.76:41

Management of a forest reserve conserving saproxylic beetles: the example of the Bois de l’Hôpital (Neuchâtel, Switzerland) Sylvie Barbalat1 Abstract The purpose of this study is to propose specific actions aiming at preserving saproxylic beetle populations, and especially rare species. The study site is a peri-urban forest above the city of Neuchâtel in western Switzerland, with oaks (Quercus sp.) and beeches (Fagus sylvatica) as dominating tree species. Its general management goal is to preserve rare plant associations and to keep characteristic fauna and flora. An inventory of four beetle families (Cerambycidae, Buprestidae, Lucanidae and Scarabaeidae subfam. Cetoniinae) was made by means of direct collection. Fifty-two beetle species were caught. Their ecological requirements were assessed and six ecological groups were identified. On this basis, proposals were made to preserve these beetles. A patchwork of forest and open biotopes favours the studied beetles. In the forest itself, tree diversity should be enhanced and old trees preserved. In the open areas, special attention should be paid to old bushes growing in the edges, which should not be removed at the time of the clearing maintenance.

Key words: saproxylic beetle conservation, forest reserve, Switzerland

1. Introduction Nowadays the role of saproxylic beetles in the forest ecosystem is becoming better understood. Saproxylic beetles are very important to enhance dead wood recycling (DAJOZ 1980, SPEIGHT 1989), as pollinators and as prey for vertebrate and invertebrate predators (GUTOWSKI 1988, IRMLER et al. 1996). More generally, Gutowski (1988) indicated that a pristine forest is less liable to Buprestidae or Cerambycidae outbreaks. They represent an important part of forest biodiversity. As an example, the Fontainebleau forest in France hosts 7600 animal species, 3000 of which are beetles (DAJOZ 2007). Köhler (2000) indicates that 56% of the forest beetles in Germany rely on wood. Saproxylic beetles are also an indicator of old growth forests close to pristine conditions (BRUSTEL 2001, SCHMIDL / BUSSLER 2004). It is therefore important that general forest management and specifically forest reserve management take into account saproxylic beetle conservation. In Switzerland, there is a government policy aiming at favouring forest biodiversity (www.bafu.admin.ch). In this perspective, the Federal Office for the Environment grants financial support for two kinds of forest reserves: total forest reserves, where no management occurs and special forest reserves, where management aims at promoting biodiversity. Based on a concrete example, the aim of this paper is to propose specific actions in view of preserving saproxylic beetle populations and especially rare species, taking into 1

account the general management of a forest reserve and the sometimes contradictory requirements of the species that are to be preserved.

2. Methods

The study area is a peri-urban 93-hectare forest located just above the city of Neuchâtel (47°00’N/ 6°56’E) in Western Switzerland, on the Jura first slopes between 550 and 600 m a.s.l. (Fig.1). It has been a forest reserve since 2001. In this thermophilous situation, the main plant associations are the following: downy oak forest (CoronilloQuercetum), sessile oak forest (Lathyro-Quercetum), beech forest (Luzulo-Fagetum and Carici-Fagetum), large black plantations of black pines (Pinus nigra), and dry meadow patches (Meso- and Xerobrometum), which were used for grazing in the past (JEANRICHARD 2003). General management aims at preserving rare plant associations, characteristic flora and fauna and especially rare species. In order to achieve these goals, the following actions are undertaken: preserving open and half-open habitats, reducing the occurrence of black pine, restoring and enhancing oak forests, and creating old tree islands. Since 2001, there has been management monitoring for the birds, butterflies, grasshoppers and plants. For the three groups, the rarest species located in the dry meadows (JEANRICHARD 2004). The forest itself is very attractive for birds as it hosts seven woodpecker species (JEANRICHARD 2003). The beetle inventory started in 2004, when management actions for the other groups were

dr., S. B., Pavés 65, CH-2000 Neuchâtel, Switzerland; [email protected]

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Saproxylic beetles in Europe: monitoring, biology and consevation

already taking place (JEANRICHARD 2003).

Deciduous tree beetle species

The following methodology was used: an inventory of four beetle families with a well-known ecology (Buprestidae, Cerambycidae, Scarabaeidae and Lucanidae) was performed. The beetles were identified to species level and their ecological requirements were assessed according to the following literature: SCHAEFFER 1949, FREUDE / HARDE / LOHSE 1966, 1969, 1979, BENSE 1995 as well as to our personal experience. On this basis, six ecological groups, mainly based on larval diet were identified. Proposals for specific management actions enhancing these beetles were made with a special emphasis on rare species for Switzerland, identified as priority species by the Swiss Centre for Fauna Cartography (www.cscf.ch). Possible conflicts between existing management actions and beetle conservation were identified and solutions are proposed.

The deciduous tree generalist beetle is less liable to be threatened than more specialised species. In this group, only Molorchus umbellatarum is considered to be a priority species. To enhance this beetle group, tree species diversity should be promoted and old trees preserved. For this beetle group as well as for all the following, it is important to maintain clear forests or clearings with flowers for the anthophilous species. These recommendations do not imply a conflict with any of the other management actions.

Direct collection was the only sampling method used. Direct collection includes: observation, beating of bushes and dead branches and looking for indirect clues (exit holes and galleries) (BRECHTEL / KOSTENBADER 2000, EHNSTRÖM / AXELSSON 2002). Twenty-five investigation tours, each of them lasting an average of 1.45 hours were performed between 2004 and 2009 from the beginning of May to the beginning of July. All the data are stored in the CSCF database. Specimens that had to be collected are in the author’s collection.

Lime tree (Tilia sp.) beetle species

Only four beetle species belong to this group, three of them being priority species: Ovalisia rutilans, Saperda octopunctata and Exocentrus lusitanus. Lime trees are not very common in Switzerland and rarely occur in large stands (DELARZE / GONSETH / GALLAND 1998). To promote lime-dependent beetles, limes and particularly old ones should be enhanced. Lime is especially favourable for the studied beetles in or near clearings, so there is a possible conflict between the aim of clearing extension and lime tree conservation. To solve this conflict, we suggest marking lime trees to be preserved in the field in order to prevent their felling at the time of clearing extension. Beetles developing in old stumps

In order to favour species developing in old stumps, such stumps have to be left after a felling. Removing stumps after a felling never occurs in the study area. Therefore, there is no identified conflict between old stump species and the other management actions taking place in Bois de l’Hôpital. The only priority and legally protected species of this group is Lucanus cervus. Bush-dependent species

Figure 1: Location of the study site.

3. Results

For the bush-dependent beetles, one has to maintain and regenerate stratified edges, preserve old bushes, enhance bush diversity, especially species hosting beetles such as Lonicera sp., Crataegus sp., Rosa sp., Daphne sp. or Rubus sp. In our study, we found the following priority species: Oberea pupillata depending on Lonicera sp., Agrilus integerrimus, depending on Daphne sp. and Agrilus sinuatus depending on Crataegus sp. There is a clear conflict with the clearing expansion, which requires the removal of bushes. As a solution, we suggest enhancing bush diversity and preserving old bushes by marking them in the field to preserve them from being logged. Oak tree beetle species

During the collection tours, 52 species were collected: 16 Buprestidae, 31 Cerambycidae, 2 Cetoniinae and 3 Lucanidae. The collected species grouped by their ecological requirements are shown on Table 1.

Beetles developing in oaks, of course, need their host plant and especially old and weakened trees, mainly in open or half-open situations. In this case, there is a possible conflict between old oak conservation and oak forest restoration, which implies logging old oaks to allow regeneration by young ones requiring much light to grow. To solve this possible conflict, a balance should be found

Barbalat, S.: Management of a forest reserve conserving saproxylic beetles...

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Table 1: Collected species grouped by their ecological requirements (taxonomy after Fauna europaea). Bold: priority species. Species

Family

Anastrangalia dubia (Scop. 1763)

Cerambycidae

Larval diet

coniferous trees

Anastrangalia sanguinolenta (L. 1761)

Cerambycidae

coniferous trees

Anthaxia helvetica Stierl. 1868

Buprestidae

coniferous trees

Anthaxia quadripunctata (L. 1758)

Buprestidae

coniferous trees

Arhopalus sp. (exit holes) Serv. 1834

Cerambycidae

coniferous trees coniferous trees

Clytus lama Muls. 1847

Cerambycidae

Stictoleptura rubra (L. 1758)

Cerambycidae

coniferous trees

Molorchus minor (L. 1758)

Cerambycidae

coniferous trees

Phaenops cyanea (exit holes) (F. 1775)

Buprestidae

coniferous trees

Rhagium inquisitor L. 1758

Cerambycidae

coniferous trees

Spondylis buprestoides (L. 1758)

Cerambycidae

coniferous trees

Agrilus cuprescens Menetr. 1832

Buprestidae

Rubus sp.

Agrilus cyanescens (Ratz. 1837)

Buprestidae

Lonicera sp.

Agrilus integerrimus (Ratz. 1837)

Buprestidae

Daphne sp.

Agrilus sinuatus (Ol. 1790)

Buprestidae

Crataegus sp.

Oberea pupillata (Gyll. 1817)

Cerambycidae

Lonicera sp.

Tetrops praeustus (L. 1758)

Cerambycidae

Crataegus sp.

Alosterna tabacicolor (De Geer 1775)

Cerambycidae

Deciduous trees

Anaglyptus mysticus (L. 1758)

Cerambycidae

Deciduous trees

Chrysobothris affinis (F. 1794)

Buprestidae

Deciduous trees

Clytus arietis (L. 1758)

Cerambycidae

Deciduous trees

Paracorymbia maculicornis (De Geer 1775)

Cerambycidae

Deciduous trees

Dinoptera collaris (L. 1758)

Cerambycidae

Deciduous trees

Grammoptera ruficornis (F. 1781)

Cerambycidae

Deciduous trees

Leiopus nebulosus (L. 1758)

Cerambycidae

Deciduous trees

Rutpela maculata (Poda 1761)

Cerambycidae

Deciduous trees

Glaphyra umbellatarum (Schreb. 1759)

Cerambycidae

Deciduous trees

Pachytodes cerambyciformis (Schrk. 1781)

Cerambycidae

Deciduous trees

Pogonocherus hispidulus (L. 1758)

Cerambycidae

Deciduous trees

Rhagium mordax (De Geer 1775)

Cerambycidae

Deciduous trees

Stenurella bifasciata (Mul. 1776)

Cerambycidae

Deciduous trees

Stenurella melanura (L. 1758)

Cerambycidae

Deciduous trees

Trachys minutus (L. 1758)

Buprestidae

Deciduous trees

Agrilus angustulus (Ill. 1803)

Buprestidae

Quercus sp.

Agrilus biguttatus (F. 1776)

Buprestidae

Quercus sp.

Agrilus laticornis (ill. 1803)

Buprestidae

Quercus sp.

Agrilus obscuricollis Kiesw. 1857

Buprestidae

Quercus sp.

Agrilus sulcicollis Lacord. 1835

Buprestidae

Quercus sp.

Anthaxia salicis (F. 1776)

Buprestidae

Quercus sp.

Grammoptera abdominalis (Steph. 1831)

Cerambycidae

Quercus sp.

Plagionotus arcuatus (L. 1758)

Cerambycidae

Quercus sp.

Pyrrhidium sanguineum (L. 1758)

Cerambycidae

Quercus sp.

Exocentrus lusitanus (L. 1767)

Cerambycidae

Tilia sp.

Saperda octopunctata (Scop. 1772)

Cerambycidae

Tilia sp.

Ovalisia rutilans (F. 1777)

Buprestidae

Tilia sp.

Stennostola dubia (Laich. 1784)

Cerambycidae

Tilia sp.

Anoplodera sexguttata (F. 1775)

Cerambycidae

old stumps

Dorcus parallelipipedus (L. 1758)

Lucanidae

old stumps

Lucanus cervus (L. 1758)

Lucanidae

old stumps

Platycerus caraboides (L. 1758)

Lucanidae

old stumps

Trichius fasciatus (L. 1758)

Cetoniinae

old stumps

Cetonia aurata (L. 1761)

Cetoniinae

organic matter

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Saproxylic beetles in Europe: monitoring, biology and consevation

between sites where oaks are regenerated and areas where old oaks are preserved. We suggest marking old oaks in the field in order to avoid their felling at the time of oak forest restoration. In this category, priority species are Agrilus obscuricollis and Grammoptera abdominalis, the larvae of which develop in dead twigs and therefore do not really depend on very big trees.

4. Discussion Except for the coniferous tree species, each ecological group hosts at least one rare species. Favouring coniferous tree beetles would imply conserving conifers, which are almost absent in the study area, with the exception of black pine. This is in contradiction with the general goal of reducing black pine occurrence. Except Spondylis buprestoides, the coniferous tree species are common mountain species (www.cscf.ch), which could extend their distribution range thanks to coniferous tree plantations to the lowlands. Continuing to reduce the occurrence of black pine might lead to a local rarefaction of these species. We believe that a forest reserve in the lowlands should not be devoted to the conservation of common mountain species outside their natural distribution range. Therefore, we do not make any proposal to solve the conflict between the coniferous tree beetle conservation and the general goal of reducing the occurrence of black pine. To a certain extent, the Bois de l’Hôpital forest reserve was created in order to protect the downy oak forest: a rare forest association. As the productivity of this forest type is very low, it had not been managed in our study site since 1955. Nevertheless, we did not find any species characteristic of pristine forest conditions. As matter of fact, this peri-urban forest was intensively managed as a coppice in the past for the production of fire wood. The present amount of dead wood ranges from 9 to 12 m³/ha (BONI pers. com.), which is higher than in the managed parts of the forest (around 5 m³/ha) (BONI pers. com.). This important habitat must have been absent long enough to provoke local extinction of the most demanding species. Nevertheless, old trees, some of them with cavities, are still present in the area and one cannot exclude the presence of relict species in very low density and out of an observer’s direct sight. A study including traps and a larger panel of saproxylic families could certainly yield interesting results in this perspective. Our results also show the importance of limes and bushes in conserving threatened species in this type of biotope.

small surface, such as the Bois de l’Hôpital, is a patchwork of forest and open biotopes. The current old trees must be preserved and mature trees should be marked out as their successors in order to avoid a time gap between the death of a very old tree and the availability of a senescent one. As a large amount of species are mono- or oligophagous, a maximum diversity of tree species must be ensured. Clearings are important to preserve plants, grasshoppers and butterflies, as well as saproxylic species needing flowers absent from the closed forest. They must be artificially maintained to avoid their recolonisation by lignous plants. Therefore, special attention should be paid at the time of their maintenance in order to conserve dry meadow surfaces for their specific flora and fauna as well as old bushes for saproxylic species. Recolonisation of relict species must be a long term goal. In this perspective, a network of old trees that could fulfil their entire biological cycle should be created.

Acknowledgements We thank the forester team of the city of Neuchâtel and especially Jan Boni, Stéphane JeanRichard and Christian Tchanz for their fruitful collaboration, as well as Oscar Barbalat for the revision of the English text and the two anonymous reviewers for their useful comments.

6. References BENSE, U. 1995. Longhorn beetles. Illustrated Key to the Cerambycidae and Vesperidae of Europe. Margraf Verlag, 512 pp. BRECHTEL, F. / KOSTENBADER, H. 2002. Die Pracht- und Hirschkäfer Baden-Württembergs. Ulmer Verlag, 632 pp. BRUSTEL, H. 2001. Coléoptères saproxyliques et valeur biologique des forêts françaises. Thèse, 327 pp. DAJOZ, R. 1980. Ecologie des insectes forestiers. Bordas, 489 pp. DAJOZ, R. 2007. Les insectes et la forêt. Lavoisier, 648 pp. DELARZE, R. / GONSETH, Y. / GALLAND, P. 1998. Guide des milieux naturels de Suisse. Delachaux et Niestlé, 413 pp. EHNSTRÖM, B. / AXELSSON, R. 2002. Insektsgnag i bar koch ved. Artdatabanken SLU, 512 pp. FAUNA EUROPAEA: www.faunaeur.org FEDERAL OFFICE FOR THE ENVIRONMENT (FOEN) : www.bafu.admin.ch FREUDE, H. / HARDE, K. W. / LOHSE, G. A., 1966. Die Käfer Mitteleuropas. Band 9: Cerambycidae, Chrysomelidae. Krafeld, Goecke & Evers Verlag, 299 pp.

5. Conclusion

FREUDE, H. / HARDE, K. W. / LOHSE, G. A., 1969. Die Käfer Mitteleuropas. Band 8. Krafeld, Goecke & Evers Verlag, 388 pp.

A forest reserve manager must deal with many species with very different and sometimes contradictory requirements. Our study shows that the best solution on a

FREUDE, H. / HARDE, K. W. / LOHSE, G. A., 1979. Die Käfer Mitteleuropas. Band 6. Krafeld, Goecke & Evers Verlag, 367pp.

Barbalat, S.: Management of a forest reserve conserving saproxylic beetles... GUTOWSKI, J. 1988. The role of Cerambycidae and Buprestidae (Coleoptera) in forest ecosystems and some remarks on their economical significance. Warsaw Agricultural University – SGGWR – AR. IV th symposium on the protection of forest ecosystems: 165-175. IRMLER, U. / KELLER, K. / WARNING, J. 1996. Age and tree species as factors influencing the populations of insects living in Dead wood (Coleoptera, Diptera : Sciaridae, Mycetophylidae). Pedobiologia 40 : 134-148. JEANRICHARD, S. 2003. La réserve à interventions particulières « Ermitage – Bois de l’Hôpital ». L’Ermite herbu: 6-12. KÖHLER, F. 2000. Totholzkäfer in Naturwaldzellen des nördlichen Rheinlands; Labdesabstakt für Ökologie, Bodenordnung und Forsten / Landesamt für Agrarordnung NRW, LÖBF-Schriftenreihe, Band 18, 352 pp. SCHAEFFER, L. 1949. Les Buprestides de France. Miscellanea entomologica, 511 pp. SCHMIDL, J. / BUSSLER, H. 2004. Ökologische Gilden xylobionter Käfer Deutschlands. Naturschutz und Landschaftsplannung 36 (7): 202-218. SPEIGHT, M. 1989. Les invertébrés saproxyliques et leur protection. Collection sauvegarde de la nature 42, 76 pp. SWISS CENTRE FOR FAUNA CARTOGRAPHY (CSCF): www.cscf.ch

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Saproxylic beetles in Europe: monitoring, biology and consevation

Saproxylic beetles in Europe: monitoring, biology and conservation, p. 17–22 GDK 145.7(450)

Walk transects for monitoring of Lucanus cervus in an Italian lowland forest Alessandro Campanaro1, Marco Bardiani2 Abstract Obtaining data on the conservation status of the species listed in Habitats Directive is a requirement of the European Commission. In order to accomplish this task and obtain comparable results from different countries, the development of standardised and simple methods, not yet formalised for most invertebrates, is necessary. A new method for monitoring the saproxylic species Lucanus cervus (Coleoptera: Lucanidae) is described in this paper. The method is based on the detection of stag beetle males during their flight period along predefined walk transects and was tested in exploratory campaigns in 2009 and 2010 in a lowland forest on the Po Plain. The method could be used in other forest areas, with specific calibrations.

Key words: Stag beetle, Lucanus cervus, transect, Habitats Directive, lowland forest, saproxylic, monitoring, conservation status

1. Introduction The stag beetle, Lucanus cervus (Linnaeus, 1758), is an obligate saproxylic species that feeds on subterranean decaying wood during the larval stages. The species is distributed widely across Europe and typically inhabits oak woodland areas, including urban parks, and isolated trees in agricultural landscapes. Detailed maps and data sources from 30 countries as well as a number of biological and ecological traits of the species have been recently reviewed in a comprehensive study that involved research from 41 countries (HARVEY et al. 2011a). The stag beetle has the IUCN conservation status of “near threatened” (NIETO / ALEXANDER 2010), and the species is listed in Annex II of the Habitats Directive. According to Articles 11 and 17 of the same directive, the conservation status of the species must be reported by each Member State every six years, which means: (1) the necessity of using the same standard method in the different sites within each country, and (2) the possibility of aggregating data coming from the different countries. This results in the need to develop a standard method across Europe. The methods thus far implemented for stag beetle surveys were reviewed in Harvey et al. (2011b). Using the remains of predation (CAMPANARO et al. 2011a) is another method that can be added to those already reviewed. Regarding initiatives at the national level, the example of the UK Great Stag Hunts, which took place in 1998, 2002 and 2006–2007, can be considered the longest and most relevant (SMITH 2011).

In Italy, we analysed and tested different survey methods in the field, as part of a broader project aimed at providing national monitoring methods for the saproxylic species of insects listed in the Habitats Directive (CAMPANARO et al. 2011b). We discussed one of these methods for L. cervus, called “walk transect and observation”, which is based on the detection and count of stag beetles at fixed points along a linear transect. Walk transects were first applied to the monitoring of L. cervus in Spain (GTLI 2005) and then adjusted in Slovenia (VREZEC / KAPLA 2007). The method discussed here was inspired by those experiences. The scientific background and the applications of the transect method for invertebrate monitoring have been discussed in a number of papers (e.g. AUSDEN / DRAKE 2006 dealt with Lepidoptera, dragonflies and damselflies). This kind of method is considered suitable for deriving abundance indices (e.g. BLONDEL et al. 1970). The walk transect method for monitoring stag beetles is described. The results obtained by the application in the Bosco della Fontana Nature Reserve (Northern Italy) and future perspectives are discussed. 2. Methods

The method implemented was based on the observation of stag beetle males during their flight period. According to the biology of the species in Italy (FRANCISCOLO 1997), the period between 7:00 and 9:00 p.m., from June to July, was chosen as the most suitable time for the monitoring of the species.

1 dr. A. C., Corpo Forestale dello Stato, Centro Nazionale Biodiversità Forestale “Bosco Fontana”, Verona (37100, IT) and Sapienza Università di Roma, Department of Biology and Biotechnology, Rome (00185, IT); [email protected] 2 M. B., Corpo Forestale dello Stato, Centro Nazionale Biodiversità Forestale “Bosco Fontana”, Verona (37100, IT); [email protected]

18

Saproxylic beetles in Europe: monitoring, biology and conservation

A number of linear transects allowing good visibility of the sky beyond the forest canopy were designed on existing tracks in 2009 and 2010. The first year of monitoring (2009) was used to test the feasibility of detecting parameters in the field, and the specific procedures of the method. The method was repeated in 2010 in the peak activity period of stag beetles, detected by non-systematic observation. Each transect was subdivided into a series of contiguous observation units (Fig. 1) represented by rectangles of fixed length (10 m). The width depended on the distance between the two margins of the forest, and could thus vary among transects; in the present case study it was 13 m. Two surveyors were necessary for each transect: Surveyor A was responsible for the sighting and counting of stag beetles, while Surveyor B was responsible for keeping the time of sighting and recording the data on a field-sheet at every stop, including the number of stag beetles observed by Surveyor A (Surveyor B could not participate in the observation). The time of observation was 30 seconds, concluded when the two surveyors moved as a pair at a distance of 10 m from one another (Fig. 1); the total duration of the transect was 1 hour. Sighting and recording of stag beetle females was allowed but these data was not used for calculation of any indices. A number of parameters were registered in the field: some were taken only once (structural parameters of the transects), others are reported every session (geographical,

physical, meteorological and ephemeral parameters). The list of parameters registered as well as the characteristics of the transects are summarised in Tab. 1. During the first year of monitoring, eight transects were set up in different parts of the forest (Fig. 2); five of these (A, B, C, D, H) were located within the area of the forest with the highest number of stag beetles (according to the results published by (CAMPANARO et al. 2011a). The monitoring took place in the second half of June: 15.06.2009 - 2 transects; 23.06. 2009 - 2 transects; 30.06.2009 - 4 transects. During the second year of monitoring, three different transects were designed (Fig. 2). Monitoring in the second year took place on 23.6.2010. Study area

The study area was the Bosco della Fontana Nature Reserve, located 5 km from the city of Mantova in northern Italy. The reserve occupies a surface of 236 ha, mainly covered by an oak-hornbeam forest (Habitats Directive code 9160: Sub-Atlantic and medio-European oak or oakhornbeam forests of the Carpinion betuli), which is one of the last remaining examples of lowland forest in the Po valley (MASON 2004). The history of the forest, the abandonment of coppicing and the recent management activities focused on the conservation of dead wood (CAMPANARO et al. 2007) have conferred on Bosco della Fontana the characteristics of an old-growth forest.

Figure 1: Schematic of the walk transect and observation for stag beetles. The grey rectangles indicate the observation unit, the black dot O1 and O2 indicate the position of the operators, t1, t2, t3 (and following) indicate the sequence of the observation units along the transect.

Campanaro, A., Bardiani, M.: Walk transects for monitoring of Lucanus cervus in an Italian lowland forest

19

Table 1: Walk transect, observation protocol, and parameters. Notes: 1 structural parameters of the transect (taken only once), 2 parameters reported every session, 3 parameters recorded for each session at the beginning and at the end points of each transect. Type of transect

Linear

Frequency

from 1 to 4 day/s

Number of surveyors per transect

2

Distance between every observation points

10 m

Total duration of the transect

60 minutes

Time of sighting at each observation unit

30 seconds

Parameters recorded for each transect

� � � � � � � � � � �

Geographic position1 (UTM WGS84) Canopy coverage1 (absent, partial, present) Human disturbance1 (high, medium, low) Presence of dead wood near the transect1 (stumps, living trees with dead wood) Type of track1 (footpath, forest track, road, other) Date of session2 (dd/mm/yyyy) Local sunset time2 (hh:mm) Weather condition2 (clear, cloudy, rain, windy) Time3 (hh:mm) Temperature3 (°C) Relative humidity3 (%)

Figure 2: Location of the transects in the map of the Bosco della Fontana Nature Reserve; the grey lines indicate forest tracks and streams, the grey area in the central part of the map indicate the grassland.

20

Saproxylic beetles in Europe: monitoring, biology and conservation

3. Results The total length of the transects ranged from 700 to 800 m, corresponding to an area comprised between 9,100 and 10,400 m² (transect G was excluded because the total transect time did not reach one hour). A maximum of 10 individuals/hour (in 2009) and 22 individuals/hour (in 2010) were detected in a single transect. These values can be considered an estimate of the number of individual males per day in each transect, because the monitoring sessions covered the entire flight activity of stag beetle males. The maximum number of stag beetles detected at a single observation point of a transect were four individuals in 2009 and three individuals in 2010. The entire sample, except one specimen collected in transect C, was represented by males. The results were expressed as total numbers of individuals per transect; this and some other parameters are summarised in Table 2.

4. Discussion The method described is the first application of transect sampling of stag beetles in Italy. The large body size, behaviour and easy detectability of L. cervus made this application possible.

The method is suitable in all forest habitats in which certain characteristics are present, such as tracks, paths or margins that create openings and walking space below the forest canopy. The “walk transect and observation method” for stag beetles can be considered a belt transect with a number of contiguous observation units shaped as rectangles set along a line. The sampling effort is standardised for a total duration of one hour. The flight behaviour of males across open spaces (e.g. the forest tracks) is typical of the biology of the species during the reproductive season. For this reason, the detectability of the species can be considered constant, accomplishing an important assumption for transect methods (FASHAM / MUSTOE 2010). The proposed method can be used in other forest areas, maintaining a fixed time of observations (30 seconds), total duration (1 hour), and length of observation units (10 m), sufficient to ensure the visibility of the beetles, also approaching at dusk (approx. time 20:30–21:30 at the Bosco della Fontana Nature Reserve). The presence of two surveyors at opposite sides of the observation unit (Fig. 1) allows easily identifying the length of the observation unit in the field. The width of the observation units is variable depending on the physical characteristics of the area and in particular on the distance between the forest margins at the two sides of the transects. The reasons for discrete observation units, instead of a continuous observation while moving, are related to: 1) the detectability of the species, because the size

Table 2: Results of the transect for the monitoring of abundance of stag beetles in the Bosco della Fontana Nature Reserve and some registered parameters. The transect code, the time, the atmospheric temperature, the relative humidity at the beginning and the end of the session, the sunset time, the weather condition and the number of specimens are reported.

Date

Transect

ti-tf

Observation points

Ti-Tf (°C)

Ui-Uf (%)

Sunset

Weather

N�

15.06.09

A

20:20–21:19

75

27.1–26.1

66–54

21:08

clear

5

15.06.09

B

20:23–21:23

77

26.6–26.1

67–58

21:08

clear

4

23.06.09

C

19:34–20:33

78

21.6–19.6

49–65

21:10

cloudy–rain

5

23.06.09

D

19:34–20:34

74

20.6–17.8

52–77

21:10

cloudy–rain

1

30.06.09

E

20:30–21:30

70

27.6–25.2

34–42

21:10

cloudy

10

30.06.09

F

20:46–21:45

75

26.8–24.1

63–73

21:10

cloudy

3

30.06.09

G

20:39–21:30

59

28.0–24.1

68–81

21:10

cloudy

6

30.06.09

H

20:30–21:31

71

26.6–23.8

78–79

21:10

cloudy

6

23.06.10

R

20:31–21:33

80

21.7–22.0

69–64

21:06

clear

22

23.06.10

S

20:33–21:33

72

22.0–25.0

70–63

21:06

clear

5

23.06.10

T

20:39–21:38

76

21.0–21.4

72–65

21:06

clear

10

Campanaro, A., Bardiani, M.: Walk transects for monitoring of Lucanus cervus in an Italian lowland forest

21

of stag beetles and the time of monitoring make detection difficult while the observer is moving; 2) the possibility of obtaining information on the distribution of stag beetles among the discrete observation units along the transect.

for calculation of the indices. If multiple repetitions are performed, the direction of the transect should be inverted at every session in order to prevent a bias concerning stag beetle detection, because observations always have to be made at the same time in the same observation unit.

Some differences were registered in the field for the total duration of the transects; this mainly depended on the different speed of the pair of surveyors in moving from one observation point to the next.

The repetition of the method every year can be used to derive population trends.

The data obtained in 2009 and 2010 confirmed a heterogeneous distribution of stag beetles at Bosco della Fontana, with the highest number of specimens observed in the transect located on the eastern side of the Reserve (Fig. 2).

5. Conclusions The method proposed and tested in the Bosco della Fontana Nature Reserve is a suitable standardised method for accomplishing the requirements of Articles 11 and 17 of the Habitats Directive. Nevertheless, a “latitudinal calibration” and a “habitat calibration” are necessary for some parameters of the monitoring protocol that depend on the characteristics of the area where the method is applied. One of the major limits of the method is the lack of visibility inside the forest. In fact, close to sunset, the detection of stag beetles becomes difficult and uncertain for individuals flying at distances of more than 2 m, and other species could be erroneously detected as stag beetles, such as the Dynastidae Oryctes nasicornis (Linnaeus, 1758) or the Cerambycidae Prionus coriarius (Linnaeus, 1758). Therefore, carrying out the last part of the transect in open areas after sunset (21:08 between June and July in Mantova) is suggested. Heavy rain and/or strong wind are other factors influencing the detection of L. cervus by means of walk transect and observation: in these weather conditions, the flight of stag beetle is strongly inhibited (FRANCISCOLO 1997, VREZEC / KAPLA 2007 cited after VREZEC et al. 2006) and the proposed method cannot applied. Instead, according to our results, clouds or light rain seem to permit the flight and allow the application of the proposed method. This method is not applicable in habitats where Lucanus cervus coexists with other species of Lucanus showing a similar behaviour, like L. tetraodon Thunberg, 1806, because the observation of specimens without direct collection does not allow their correct determination. Due to the uneven distribution of suitable habitats for Lucanus cervus in a forest, results cannot be expressed as density but only as abundance indices. More sessions of walk transects during the season (one session every 3–4 days during the flight period) provided more accurate data

Acknowledgements The development and testing of the transect method was possible with the help of many people. We are grateful to: Franco Mason (Centro Nazionale Biodiversità Forestale “Bosco Fontana”, Verona, Italy) as promoter of this study; Francesca Della Rocca (University of Pavia, Italy), Stefano Focardi (ISPRA, Bologna, Italy), Marcos Méndez (Universidad Rey Juan Carlos, Madrid, Spain), Al Vrezec (National Institute of Biology, Ljubljana, Slovenia) and Livia Zapponi (Centro Nazionale Biodiversità Forestale “Bosco Fontana”) for useful methodological information; Daniel Whitmore (Centro Nazionale Biodiversità Forestale “Bosco Fontana) for the linguistic revision of the text. Thanks to our colleagues at Centro Nazionale Biodiversità Forestale “Bosco Fontana” Donatella Avanzi, Daniele Birtele, Serena Corezzola, Paolo Cornacchia, Liana Fedrigoli, Rosy Fezzardi, Sönke Hardersen, Massimo Lopresti, Fabio Mazzocchi, Emma Minari, Gianluca Nardi, Laura Spada and Ilaria Toni for fundamental field work and useful advice. We also thank Emanuela Bastianelli, Roberto Budinho, Alberto De Iseppi, Paola Ferretti, Davide Montanari, Alessandro Morelli, Rita Pesti, Arianna Quaratino, Alberto Rigamonti, Paolo Sassi, Erica Simoni, Benedetta Zecchini (Mantua) and Christian Nogara (Verona), who voluntarily took part in the transects as surveyors. The research was financed by “Ministero dell’Ambiente e della Tutela del Territorio e del Mare” and “Corpo Forestale dello Stato” within the project “Linee guida per il monitoraggio e la conservazione dell’entomofauna saproxilica”.

6. References AUSDEN, M. / DRAKE, M. 2006. Invertebrates. In: SUTHERLAND W.J. (ed.) Ecological Census Techniques. A handbook. Second edition. Cambridge University Press: 214-260. BLONDEL, J. / FERRY, C. / FROCHOT, B. 1970. La méthode des indices ponctuels d’abondance (I.P.A.) ou des relevés d’avifaune par “stations d’écoute”. Alauda 38: 55−71. CAMPANARO, A. / BARDIANI, M. / SPADA, L. / CARNEVALI, L. / MONTALTO, F. / ANTONINI, G. / MASON, F. / AUDISIO, P. 2011b. Linee guida per il monitoraggio e la conservazione dell’entomofauna saproxilica. Quaderni Conservazione Habitat, 6. Cierre Grafica, Verona, 8 pp. + CD-ROM. CAMPANARO, A. / HARDERSEN, S. / MASON, F. 2007. Piano di gestione della Riserva Naturale Statale e Sito Natura 2000 “Bosco della Fontana”. Quaderni Conservazione Habitat, 4. Cierre edizioni, Verona, 221 pp.

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CAMPANARO, A. / TONI, I. / HARDERSEN, S. / GRASSO, D. A. 2011a. Monitoring of Lucanus cervus by means of Remains of Predation. Entomologia Generalis, 33(1-2): 79−89. FASHAM, M. / MUSTOE, S. 2010. General principles and methods for species. In: Handbook of Biodiversity methods (HILL, D. / FASHAM, M. / TUCKER, G. / SHEWRY, M. / SHAW, P. (eds.). Cambridge University Press: 255–270. FRANCISCOLO, M. E. 1997. Fauna d’Italia, XXXV. Coleoptera Lucanidae. Calderini, Bologna, I−XII + 228 pp. GTLI (Grupo de Trabajo sobre Lucanidae iberico) 2005. Proyecto ciervo volante. Available at http://www.sea-entomologia. org/PDF/BOLETIN_11/B11-010-041.pdf [accessed 5 December 2011]. HARVEY, D. J. / GANGE, A. C. / HAWES, C. J. / RINK, M. 2011a. Bionomics and distribution of the stag beetle, Lucanus cervus (L.) across Europe. Insect Conservation and Diversity, 4 (1): 23−38. HARVEY, D.J. / HAWES, C. J. / GANGE, A. C. / FINCH, P. / CHESMORE, D. / FARR, I. 2011b. Development of non-invasive monitoring methods for larvae and adults of the stag beetle, Lucanus cervus. Insect Conservation and Diversity, 4 (1): 4−14. MASON, F. 2004. Dinamica di una foresta della Pianura Padana. Bosco della Fontana. Primo contributo, monitoraggio 1995. Seconda edizione con linee di gestione forestale. Rapporti scientifici, 1. Gianluigi Arcari Editore, Mantova, Italy, 224 pp. NIETO, A. / ALEXANDER, K. N. A. 2010. European Red List of Saproxylic Beetles. Publications Office of the European Union, Luxembourg, 45 pp. SMITH, M. N. 2011. Great Stag Hunt III: National stag beetle survey 2006−2007. People’s Trust for Endangered Species, London, 22 pp. VREZEC, A. / KAPLA, A. / GROBELNIK, V. / GOVEDIOE, M. 2006. Analiza razširjenosti in ocena velikosti populacije rogaoea (Lucanus cervus) s predlogom conacije Natura 2000 območja Goričko (SI3000221). (Projekt: »Zasnova conacij izbranih Natura 2000 območij« (7174201-01-01-0002) Phare čezmejno sodelovanje Slovenija-Avstrija 2003). Nacionalni inštitut za biologijo, Ljubljana & Center za kartografijo favne in flore, Miklavž na Dravskem polju. VREZEC, A. / KAPLA, A. 2007. Kvantitativno vzorčenje hroščev (Coleoptera) v Sloveniji: referenčna študija. Acta Entomologica Slovenica, 15 (2): 131−161.

Saproxylic beetles in Europe: monitoring, biology and conservation, p. 23–32 GDK 145.76(497.4)

Biodiversity of saproxylic beetles of pine forests in Slovenia with emphasis on Monochamus species Maja Jurc1, Srdjan Bojovic2, Roman Pavlin3, Gregor Meterc4, Andreja Repe5, Danijel Borkovič6, Dušan Jurc7 Abstract From 2007 to 2010, we assessed the presence of entomofauna in two ecological regions of Slovenia on three locations: on limestone parent rock in monocultures of Pinus nigra, on flysch in a stand of Pinus halepensis (both in the Sub-mediterranean ecological region) and in a stand of Pinus sylvestris on brown soil (Pre-alpine ecological region). The samples were collected in one-month intervals from May to November using four cross vane funnel traps per location with wet collecting cups and attractants (ethanol+αpinene, Pheroprax® and Gallowit®). Collected insects from the order Coleoptera belonged to the families Curculionidae (and subfam. Scolytinae), Cerambycidae and Buprestidae. The most important saproxylic groups were Scolytinae as the primary saproxylic beetles at 90.7% (21,820 specimens), containing 21 taxa and 18 species; Cerambycidae at 6.4 % (1534 specimens), 24 taxa, 20 species; Curculionidae at 2.5% (613 specimens), eight species and Buprestidae at 0.4% (90 specimens) and one species. With respect to the number of species identified, the most numerous family was Cerambycidae; the dominant species was Spondylis buprestoides, followed by Rhagium inquisitor, Arhopalus rusticus, Acanthocinus aedilis, Neoclytus acuminatus, Monochamus galloprovincialis, Leiopus nebulosus, Arhopalus ferus, Sticoleptura rubra and Cerambyx scopoli. Collected species of long-horned beetles represent ca. 10% of all known species of Cerambycidae in Slovenia. With regard to our findings, we can conclude that Slovenian forestry legislation (Act of Forestry 1993 and Rules on the Protection of Forests 2009) regarding the protection of forest biodiversity is appropriate for the preservation of saproxylics.

Key words: Pine forests, saproxylic beetles, Cerambycidae, ethanol+α-pinene, Pheroprax®, Gallowit®

1. Introduction According to the data of the Slovenian Forest Service, in 2010 forests occupied 1,185,169 ha, which represents 58.8% of the total surface area of the country. The growing stock of Slovenian forests was 330,982,374 m³ or 279.72 m³/ha. Conifer trees’ growing stock is 46.43%, and deciduous trees’ stock is 53.57%. The yearly increment of trees in the forests is 8,117,325 m³ or 6.85 m³/ha (ZGS 2010). In 2008, the share of all species of pines in the growing stock amounted to 19,527,961 m³, which represents 5.9% in the total growing stock of forests. In Slovenia the following species of pines are present: Pinus nigra, P. sylvestris, P. mugo, P.halepensis, P. pinea, P. strobus, P. cembra, P. pinaster, but only four of them are native (P. nigra, P. sylvestris, P. mugo and P. cembra). P. sylvestris dominates among all pines, its proportion in the pine growing stock is 72.8% or 14,216,874 m³ and it appears on 310,513 ha, while the area of stands with more than 50% of P. sylvestris in the growing stock amounts to 36,833 ha. Up to 51.4% of P. sylvestris is (according to diameter of breast height (dbh)) classified in the thickness class of 30–50 cm, 37.3% in thickness class of 10–30 cm and 8.3% in the thickness

class of over 50 cm dbh. The second most common species of pine in Slovenia is P. nigra; its proportion the wood stock of pine is 25.3% or 4,935,411 m³ and appears on 67,882 ha, while the area of stands with more than 50% of P. nigra trees in the growing stock is 23,516 ha. The largest number of P. nigra trees according to the dbh is in the thickness class 30–50 cm and it comprises 49.4%; in the thickness class of 10–30 cm it is 43.4% and 7.2% of the trees in the thickness class of over 50 cm dbh (ZGS 2008a). In Europe and also in Slovenia, anthropogenic impacts on natural forest vegetation have been very substantial; the result of those effects was (among others) the loss of habitats of saproxylic organisms. In prehistoric times, inappropriate treatment with forests on the territory of Slovenia took place, stacks of charcoal and ashes in karst caves have been detected (JURHAR et al. 1963). After the 15th century, areas were deforested with slash and burning; this continued until the 19th and 20th centuries (Enciklopedija Slovenije 1995). P. nigra is found in the Sub-mediterranean ecological region and was planted in the 19th and 20th centuries during the period of the AustroHungarian Empire; since then, it has been regenerating on abandoned land. This afforestation has been large and successful. Until recently, it has encompassed more than 20,000 ha of plantations and areas with natural regeneration

prof. dr. M. J., Biotechnical Faculty, Dpt. of Forestry and Renewable Forest Resources, Večna pot 83, 1000 Ljubljana, Slovenia; [email protected] dr. S. B., Institute for Biological Research S. Stankovic, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade; Serbia; [email protected] 3 R. P., Biotechnical Faculty, Dpt. of Forestry and Renewable Forest Resources, Večna pot 83, 1000 Ljubljana, Slovenia; [email protected] 4 G. M., Biotechnical Faculty, Dpt. of Forestry and Renewable Forest Resources, Večna pot 83, 1000 Ljubljana, Slovenia; [email protected] 5 A. R., Biotechnical Faculty, Dpt. of Forestry and Renewable Forest Resources, Večna pot 83, 1000 Ljubljana, Slovenia; [email protected] 6 D. B., Biotechnical Faculty, Dpt. of Forestry and Renewable Forest Resources, Večna pot 83, 1000 Ljubljana, Slovenia; [email protected] 7 prof. dr. D. J., Slovenian Forestry Institute, Večna pot 2, 1000 Ljubljana, Slovenia; [email protected] 1 2

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Saproxylic beetles in Europe: monitoring, biology and conservation

of P. nigra. In the study area, P. nigra is not native, and it has been weakened by exposure to biotic and abiotic damage. Elswere in Europe, there was also no proper method of managing forests, so primeval forests in Europe are very rare; their surfaces are small and fragmented, and therefore the saproxylic biodiversity is also diminished. The group of saproxylic beetles in Europe is, because of the small amounts of decomposing wood in forests, one of the most endangered groups of beetles; many of them are on the red list of endangered species and lists of Natura 2000. In recent times, the saproxylic species are endangered in most of its original territory because of intensive forest management and the loss of primeval forest conditions. Under the influence of fire and others factors, specific habitats, such as old and dead trees, have disappeared. The surface area of mature forests has been reduced, and there have also been changes in the size of patches of old trees (KOUKI et al. 2001). Data from the World Resources Institute from Washington shows that around 40% of forests in the world still have characteristics of mature forests. In some European countries, the proportions of mature forest are lower; for example, in Sweden the proportion of mature forest is only 3% (BRYANT et al. 1997). Saproxylic organisms contribute significantly to forest biodiversity, representing 20–25% of all species living in forests (SIITONEN 2001). Analysis of the conservation of the forests in Slovenia, however, shows a relatively favourable situation, contributing to conservation of the habitats of saproxylic beetles. Based on the data from permanent sample plots in forests (n = 94,660) of the Slovenian Forest Service (2008b), the amount of dead wood in forests is 3.6% of the growing stocks of forest stands, representing 10 m³/ha of dead wood mass or 26 dead trees with diameters of more than 10 cm per ha of area. The proportion of deciduous trees is 56%, while the proportion of conifers is 44% (POLJANŠEK 2008). Our study was conducted within the framework of national monitoring of Monochamus spp. (Col.: Cerambycidae) as vectors of pine wood nematode (PWN) in Slovenia; we present the part of the results related to saproxylic beetles. In recent years, interest in the Monochamus species has increased because these species are vectors of the PWN, Bursaphelenchus xylophilus (NICKLE, 1970) (Tylenchida: Aphelenchoididae), (STEINER and BUHRER 1934), which causes the fatal pine wilt disease of some pine species in Japan and other Asian and also European countries (SOUSA et al. 2001). EVANS et al. (1996) have demonstrated in pest risk assessments that the nematode can survive in Europe, but extensive damage and tree mortality are likely to be restricted to the warmer southern countries. Taking into account the bioclimatic parameters such as temperature, hosts (particularly Pinus sylvestris and P. pinaster) and vectors, pine wilt disease has the potential to become a major threat if it is introduced

to other European countries; it could become one of the most serious threats to pine forests worldwide in the 21st century (ØKLAND et al. 2010, TOMICZEK / HOYERTOMICZEK 2008), including in Slovenia (JURC et al. 2003). A variety of approaches have been investigated for the management of wood-boring insect populations. These insects are attracted to potential hosts by volatile compounds and possibly by visual cues. Few studies have examined traps of different designs to determine the influence of silhouette and shape on the capture of Monochamus species. Groot and Nott (2002) have recommended a pan trap with a black silhouette for general use in capturing woodboring Cerambycidae. Other authors have recommended the use of conventional multiple funnel traps with certain modifications, such as multiple funnel traps with waterfilled collecting cups or large-bottom funnels and cross vane traps with a prominent silhouette (MOREWOOD et al. 2002). Some authors have recommended the suspension of multiple funnel traps from ropes between trees with the uppermost funnel at a height of 1.8 m above the ground (IBEAS et al. 2007). In North America, several researchers have demonstrated a kairomonal response of Monochamus titillator to blends of bark beetle pheromones acting synergistically with a turpentine host (BILLINGS / CAMERON 1984, BILLINGS 1985). Other investigations have shown that ipsenol and ipsdienol, aggregation pheromones of Ips DeGeer, 1775 species, are highly synergistic with α-pinene and ethanol in attracting Monochamus clamator and Monochamus scutellatus, whereas pheromone compounds from Dendroctonus Erichson, 1836 species are not (ALLISON et al. 2003). In Spain, Pajares et al. (2004) have studied the effects of bark beetle (Ips spp.) pheromone components, released individually (ipsenol) or in blends (ipsenol, ipsdienol, cisverbenol and methyl-butenol), together with host volatiles (turpentine or α-pinene and ethanol) on Monochamus galloprovincialis trap catches. They found that the full blend of the four Ips semiochemicals with the host compounds is highly attractive. The latest research shows some news on sex attraction and mating behaviour in M. galloprovincialis (IBEAS et al. 2007, IBEAS et al. 2009), and considerable progress has been made in the study of M. galloprovincialis pheromones. Pajares et al. (2010) have found that 2-undecyloxy-1-ethanol is a male-produced aggregation pheromone of the pine sawyer beetle, and that this compound is potentially useful at a concentration range that is suitable for trap bait. In this paper, we report the results of field experiments designed to a) evaluate the kairomonal responses of saproxylic beetles in three types of pine forests in Slovenia, b) assess biodiversity of saproxylic beetles depending on the sampling method used, and c) establish the effectiveness of forestry legislation which regulates the quantity of dead wood in forests as habitats of saproxylic beetles.

Jurc, M., Bojovic, S., Pavlin, R., Meterc, G., Repe, A., Borkovic, D., Jurc, D.: Biodiversity of saproxylic ...

2. Materials and methods 2.1. Field tests

Entomofauna was collected during the growing seasons from May 2007 to Novembar 2010 at three different sites in western, south-western and central Slovenia (Kastelec, Dekani, Brdo pri Kranju, respectively). We monitored saproxylic beetles, and tested the effectiveness of an ethanol+α-pinene blend and two commercial baits under different ecological conditions and in different host tree stands. The locations and sampling dates are summarised in Table 1. In the Sub-mediterranean ecological region, the climate is Sub-mediterranean: average yearly temperature is 13.8 ºC; average growing season temperature is 21.6 ºC; maximum temperature is above 27 ºC; minimum temperature is below 16 ºC; precipitation is 1031 mm. In the Pre-alpine ecological region, the climate is alpine: average yearly temperature is 9.5 ºC; average growing season temperature is 17.8 ºC; maximum temperature is above 24 ºC; minimum temperature is below 12 ºC; precipitation is 1336 mm, (Statistical Yearbook of the Republic of Slovenia 2000 – 2010). Material was collected using black cross vane funnel traps (WitaPrall IntPt – Nassfalle, Witasek PflanzenSchutz GmbH) equipped with wet collecting cups and attractants; in each location, there were four traps at a height of about 2 m on self-supporting stages, the distance between the traps was at least 50 m. At each location, one trap contained a blend of ethanol (p.a., Merck) and α-pinene (98%, Sigma-

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Aldrich), released at about 2 g/day at 25–28 °C; one contained the pheromone Pheroprax® (BASF) (ingredients: 2-methylbut-3-en-2-ol); one contained Gallowit® (Witasek PflanzenSchutz GmbH) (ingredients: ipsdienol CAS 14434-41-4, ipsenol CAS 60894-96-4, DMWK CAS 11518-4, cis-verbenol CAS 18881-04-4, α-pinene CAS 80-568, ethanol CAS 64-17-5); and one contained no attractants as a control. All collecting cup were filled with 200 ml of propylene glycol to preserve the collected entomofauna. The samples were collected at one-month intervals, fixed with 0.1% benzoic acid (C6H5COOH) (p.a., Merck), prepared, identified (determination keys and catalogue used: BENSE 1995, FREUDE et al. 1966, GRÜNE 1979, PFEFFER 1995¸ SAMA 2002, LÖBL / SMETANA 2006) and deposited in the entomological collection of the Biotechnical Faculty, Department of Forestry and Renewable Forest Resources, in Ljubljana. 2.2. Statistical analysis

Variables were ln (x+1) transformed whenever found to be non-normal (P