RESOLVING CONFLICTS BETWEEN RECREATION AND CONSERVATION IN BRITAIN'S URBAN WOODLANDS - A MANAGEMENT GUIDE by JAMES LITTLEMORE* SUMMARY
Urban woodlands provide a range of opportunities for people to enjoy open-air recreation. Unfortunately, recreational trampling is a major contributor in facilitating ecological change in these woods, threatening their wildlife conservation value. This paper discusses the various woodland management techniques which are available to help to resolve conflicts between recreation and conservation in urban woods. Introduction A substantial area of Britain's woodland consists of small fragments located on the urban fringe. These woods offer incredible opportunities for recreational activities to take place and remain a valuable free recreational resource which provides benefits for people's physical and mental satisfaction. The most common forms of recreational use occur in open areas of woodlands and along footpaths, rides, tracks and bridleways (collectively termed 'trails' in this paper). There, informal recreational activities, such as dog walking, picnicking, horse riding, jogging and mountain hiking, take place alongside more formal recreational activities, such as paintball games, orienteering, guided walks, conservation work parties and educational visits. Urban fringe woodlands are also used for anti-social and occasionally illegal activities such as vandalism, the abuse of drugs and alcohol, rubbish tipping, homes for vagrants and motorbike scrambling (Barker and Littlemore, 1997). The demand for recreation in British woodlands is increasing, with woodlands in England and Wales receiving a staggering 330 million day visits a year (National Centre for Social Research, 1999). A Countryside Commission (now the Countryside Agency) report published in 1999 called for trees, forests and woodlands to play a more major role in the continuing development of recreation opportunities close to people's homes. Along with the push for increased access to forests and woodlands through the Access to the Countryside Bill (DETR Consultation Paper, 1998), potential recreational impacts are considerable. This trend of increasing recreational use is creating huge problems for woodland managers who have to deal with the conflicts between recreation and conservation. The Ecological Impact of Recreation in Woodlands The primary impact of recreation is through trampling by people or other large mammals and from the passage of machinery. Unfortunately, most forms of recreational activity are incompatible with priorities for wildlife (Speight, 1973) and * Countryside Management Section, Pitsford Centre, Moulton College, Moulton, Northampton NN3 7RR. E-mail:
[email protected] James Littlemore is a lecturer in countryside and water management at Moulton College. He previously undertook postgraduate research into the impacts of recreation in woodlands at the University of Warwick.
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overuse by visitors and lack of management will lead to the degradation of woodlands of high nature conservation value. Recreational trampling is linked with two main impacts. i. The deterioration of woodland ground vegetation Recreational trampling in woods causes losses in ground-flora plant cover, height and species richness (Cole, 1985; Littlemore, 1998). In addition, as most woodland ground-flora species possess delicate leaves and stems, a single exposed perennating organ and adaptations to moist, undisturbed soils, they are extremely vulnerable to prolonged spells of recreational trampling (Littlemore, 1998).
ii. Changes to soil conditions along trails The soil conditions along woodland trails deteriorate with increasing levels of trampling. They become heavily compacted with underlying mineral soils exposed at the expense of accumulated woodland litter and humus layers, which are fragmented and broken up by treading (Littlemore, 1998). The end result will be an increase in soil erosion, with exposure and damage to tree roots. The Ecological Carrying Capacity of British Woodlands The definition of ecological carrying capacity is modified from Speight's (1973) as: "The maximum intensity of use, measured in terms of the number of people a year woodland ground vegetation will support without undergoing an unacceptable degree of ecological change away from the original ecosystem condition considered desirable." Unfortunately, the ability of woods to accommodate free-roaming visitors is much lower than thought previously (Barker and Littlemore, 1997; Littlemore, 1998). Therefore, in order that the ecological integrity of Britain's more popular urban woodlands are preserved, the number of people visiting these sites needs to be
controlled at or below those ecological carrying capacities specified in Table 1. The carrying capacity of woodland vegetation under heavy shade is lower than vegetation in more open light climates (Littlemore, 1998). Therefore, stands beneath Table 1. The ecological carrying capacity of woodland ground flora for recreation (after
Littlemore, 1998).
dominant species in vegetation stand
ecological carrying capacity (people/year)
Hyacinthoides non-scripta (bluebell) heavily-shaded coniferous cover
50-75
Hyacinthoides non-scripta partially-shaded deciduous cover
75-100
Pteridium aquilinum (bracken)
100-150
Rubus fruticosus agg (bramble)
100-150
11] Assuming a single person makes one walking pass. Approximations of carrying capacity were made by quantifying the amount of trampling (in number of passes per year) which created a noticeable path and the amount of trampling (in number of passes per year) which caused paths to remain noticeable after a full year's recovery. 12] If the ecological carrying capacity is based on the ability of Hyacinthoides non-scripta to produce flowers and seeds instead of basing it on vegetative biomass and cover, then the carrying capacity drops to just 25 passes per year.
Indeed, seed production in Hyacinthoides non-scripta dramatically declines to just one-tenth of that of an undisturbed patch once 200 people have walked through (Barker and Littlemore, 1998).
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senile coppice, overgrown plantation woodland and dense shrub layers are at particular risk. Using Cole's (1985) estimate of the impact of camping on forest vegetation, woodlands should not be used for more than one night a year for camping and, even if woodland vegetation is present on the periphery of camp-sites, woodland managers should expect some deleterious impacts encroaching into their woods. The process of restoration after trampling, back to the native floral diversity, is slow. Even though vegetative productivity will return in a few years, the restoration of original floristic characteristics will take much longer (Littlemore, 1998). Nevertheless, the recovery of vegetation from low levels of trampling in fairly open woodland will occur approximately four weeks after trampling, provided that there is
a complete cessation of impact (Littlemore, 1998). Recovery rates will also depend on the nature of the vegetation which has been affected. For instance, stands dominated by Rubus fruticosus agg or Pteridium aquilinum will take up to two years to recover from one season of heavy trampling but Hyacinthoides non-scripta will take up to five (Littlemore, 1998). The recovery rates of woodland soils are also notoriously slow. For example, trails subjected to a single season of heavy trampling by 500 people will take at least six years to recover to the pre-trampling conditions (Littlemore, 1998). Predicting the Ecological Impacts of Recreation in Woodlands Woodland managers can obtain an immediate appraisal of the potential of a site to withstand recreational use by examining the various plant strategies which are exhibited by in situ ground-flora species. Impacts will be greatest in tall, herbaceous and woody vegetation, which exploit shady conditions of high environmental stress and competition; for example, Mercurialis perennis (dog's mercury), Anemone nemorosa (wood anemone) and woodland ferns (Littlemore, 1998). Impacts will be lessened in short, rosette and tussocky vegetation which thrives in open or partially-shaded conditions of high environmental disturbance; for example, sedges, rushes and grasses (Littlemore, 1998). An index of vulnerability to trampling is provided in Table 2 (after Littlemore, 1998). It enables woodland managers to assess the potential of woodland stands to withstand recreational damage. Individual stands can be assessed using the index, or even specific species and other non-woodland habitats. The index of vulnerability was applied to undisturbed ground flora in Tocil Wood (SP 303 764), Warwicks, during the spring of 1998. The vegetation was dominated by a homogeneous stand of Hyacinthoides non-scripta in a National Vegetation Classification W10 Quercus robur-Pteridium aquilinum-Rubus fruticosus woodland community (Rodwell, 1991).
It scored as follows: 1. suburban - 1 point 2. partial shade - 1 point 3. moist - 0 4. monocots - 0 5. intermediate - 1 point 6. narrow - 1 point 7. brittle - 2 points 8. erect herbaceous - 2 points 9. geophytes - 2 points
10. C-S-R intermediates - 1 point final score = 11 points
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Table 2. An index of vulnerability for woodland sites, using environmental characteristics as
weighting factors. Sites for evaluation are graded 2,1 or 0 points on each of the 10 environmental factors, yielding a score which ranges from 0 to 20 points (0 to 5 = not vulnerable; 6 to 10 = intermediate; 11 to 15 = vulnerable; 16 to 20 = extremely vulnerable).
environmental factor
2 points
score 1 point
0 points
locality
urban
suburban
rural
light climate
heavily shaded
partial shade
open
soil moisture status
wet
dry
moist
typical ground flora
dicots
mixed
monocots
ground vegetation
tall
intermediate
short
leaf morphology
wide, large, delicate
narrow
flat, small, tough
stern structure
brittle, rigid
branched, layered,
flexible, tussocky
stature
woody growth form 1
life forml ]
erect herbaceous, woody
prostrate
rosette, tussock/tufted
phanerophytes,
therophytes, semi-rosette hemicryptophytes
hemicryptophytes
C-S-R intermediates
ruderals
geophytes,
chamaephytes proto-hemicryptophytes ecological strategyt2!
competitors
rosette
[1] Phanerophytes are woody plants with buds >25cm above the soil surface; chamaephytes are woody or herbaceous plants with buds above the soils surface but
