Towards a common methodology for efficient bryophyte and lichen long-term monitoring at species and community level in Portugal Helena Hespanhol1, Cristiana Costa Vieira1, Joana Marques1,2 1 2
Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto (CIBIO-UP). Faculdade de Ciências, Universidade do Porto (FC-UP).
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Introduction
Table 1: Examples of the most recent literature research on long-term monitoring of bryophytes and lichens.
Currently, natural habitats are subjected to profound environmental changes and a decline of plant diversity has been observed over long temporal and broad spatial scales. Bryophyte and lichen long-term monitoring presents considerable problems, since these organisms are sometimes inconspicuous, especially endangered ones, and their identification might be difficult and time-consuming, even for specialists. Although there are some published studies about sampling techniques and monitoring guidelines for bryophyte and lichen species in the literature (especially for epiphytes), broad scale bryophyte and lichen monitoring programs are globally rare (see table 1) and are mainly focused on pollution rather than on diversity changes. In Europe, large-scale pollutant monitoring programs using bryophytes and lichens and monitoring projects focused on epiphytic lichens are successfully implemented, profiting from the easier recognition of most species in the field and consequent reduction of time and costs. The aims of this study were to collect and summarize information on (i) the methodologies for species and community long-term monitoring adopted in other countries and (ii) the inclusion of bryophytes and lichens in environmental impact assessments or monitoring procedures occurring in Portugal. In addition, four case-studies to develop ideas on the best methodologies for long-term monitoring and a framework of the possible monitoring methodologies for Portuguese reality are presented.
Author and Country publication year Doubt & Belland, Western 2000 Canada (Alberta)
Type of monitoring Forested zones monitoring
Monitoring targets Bryophyte and lichen species
Monitoring reasons/aims Monitoring protocols to assess human-induced changes in nonvascular plant diversity
Monitoring method Estimation of % cover of common species within sub-plots of a 100x100 m plot and collection of non-common species in microhabitats
JNCC, 2005
UK
Monitoring of habitats associated with bryophyte and lichen interest features
Bryophyte and lichen species
Surveillance and monitoring program in the UK
List of rare and scarce species found within the habitats and an indication of their extent within the habitat
Papp et al., 2005
Hungary
Long-term monitoring program
Bryophyte species and community
National Biodiversity Monitoring System
Species: estimation of the number of indivuals and population size; Community: list of species weigthed with abundance in the quadrate; systematic sampling recording presence/absence
Hofmann, 2008
Switzerland
Monitoring of priority species of mosses
Bryophyte species
Monitoring project of the National Inventory of Swiss Moss Flora
Recording sheet with accurate localization of a population using GPS, field sketches and recessed magnets
Stahl et al., 2011
Sweden
Multiscale biodiversity monitoring system
Bryophyte and lichen species
Monitoring program of Permanent circular sample plots within National Inventory of the 1km2 squares, where the presence or Landscapes in Sweden absence of a number of common or characteristic lichens and bryophytes are registered
Four case-studies to be implemented in Portugal 2. Optimization of protocols for long-term monitoring of bryophyte and lichen communities
1. Optimization of protocols for long-term monitoring of bryophyte and lichen species •A. Monitoring target • Bryophyte species listed in Habitats Directive (e.g. Bruchia vogesiaca, Bryoerythrophyllum camplylocarpum, Marsupella profunda) or threatened bryophyte species listed in Iberian or National Red Lists; •lichen species listed in Habitats Directive (e.g. Cladonia stygia) or Iichen species with rare occurrence in Portugal (e.g. Epiphloea terrena, Leptochidium albociliatum, Massalongia carnosa, Peltula euploca); •Invasive bryophyte species, such as Campylopus introflexus. •B. Monitoring parameters/ type of data •Percentage cover; •Reproductive biology parameters. •C. Aim/ Monitoring questions related to sampling design • a) Which is the best monitoring method? •Permanent plot monitoring •b) Which is the best plot size? • 50x50 cm quadrats •c) Which is the minimum number of replicates? •5 •d) Other questions are related to: • Site selection and species selection
Figure 1. Example of a permanent monitoring plot on a rock surface in order to monitor a threatened bryophyte species – Coscinodon cribrosus - in Portugal.
• A. Monitoring target • Saxicolous (terrestrial and aquatic) and terricolous (dune and skeletal soils) communities. • B. Monitoring parameters/ type of data • Percentage cover of species within a monitoring plot; • C. Aim/ Monitoring questions related to sampling design • • • • • • • •
a) Which is the best monitoring method? Permanent plot monitoring b) Which is the best plot size? 50x50 cm quadrats c) Which is the minimum number of replicates? 5 d) Other questions are related to: Site selection
Figure 2. Example of a permanent monitoring plot on a rock surface for saxicolous communities monitoring.
3. Applicability of functional groups on long-term monitoring of bryophyte and lichen communities
4. Fixed-point photography applied to long-term monitoring of bryophyte and lichen species and communities
• A. Monitoring target • Bryophyte and lichens species and functional groups response along modified gradients.
• A. Monitoring target • Bryophyte and lichen species, functional groups and communities.
• B. Monitoring parameters/ type of data • Percentage cover of functional classes and each species within a plot monitoring .
• B. Monitoring parameters/ type of data • Percentage cover of species or species groups within a monitoring plot.
• C. Aim/ Monitoring questions related to sampling design
• C. Aims/ Monitoring questions related to sampling design
• a) Are the functional groups an alternative to species identification? • Comparative study using the same plots and two groups of information (species level and functional groups level). • b) Which is the best monitoring method? • Permanent plot monitoring • c) Which is the best plot size? • 50x50 cm quadrats and zones • d) Which is the minimum number of replicas? •5 • e) Other questions are related to: • Site selection
• a) What communities or species give the most accurate results? • In this case study the efficiency of fixed-point photography on long-term monitoring will be assessed, on horizontal or vertical surfaces, by comparison with classical techniques of inventory by direct observation.
Figure 3. Example of a permanent monitoring plot (and zones) on a rock surface in the river margin for saxicolous communities functional groups monitoring.
Monitoring aims and methods proposed for Portugal for each level of ecological organization •In Portugal there is a tendency to focus the monitoring programs on vascular plants and to limit its application to environmental impacts studies. Bryophytes and lichens were only recently included as components of the flora in the context of some environmental impact assessments. However, this inclusion has been sporadic, since there is no legal obligation of studying these organisms and the impacts on them in such studies. •So far, there is no national program for long-term monitoring of bryophyte and lichen species and communities, either due to the reduced number of specialists, or to the absence of standard methodologies for the majority of habitats, with the exception of epiphytic habitats, whose monitoring methodology has been widely implemented in Portugal.
Monitoring scale
Monitoring targets
Species level Threatened Rare
Community level
Monitoring methods
Monitoring aims
Permanent quadrats and fixed-point photography Permanent quadrats
• Species trends due to legislative demands (national law or European directive); • Effects of management actions, natural disturbances or environmental impact assessments on species.
Invasive
Permanent quadrats/transepts
Terricolous
Permanent quadrats
Saxicolous
Permanent quadrats and fixed-point photography
Epiphytes
Permanent quadrats
• Functional groups trends, instead of species trends within each community; • Effects of management actions, natural disturbances or environmental impact assessments on communities
Figure 4. Example of a result from image analysis through unsupervised pixel classification (K-means) performed in R software.
Concluding remarks It is expected that this synthesis and the following work will result in a series of recommendations that could be encompassed by Portuguese law or environmental technicians, namely: (1) the selection of habitats for the implementation of bryophyte and lichen species and community monitoring, in the context of environmental impact assessments; (2) the presentation of standardized methodologies for bryophyte and lichen community monitoring, in line with similar systems adopted in other countries; and (3) the definition of protocols for species monitoring. All these insights are expected to contribute to a common methodology for efficient bryophyte and lichen long-term monitoring at species and community level in Portugal.
