Vegetation trampling resulting from recreation can adversely impact natural habitats, leading to the loss of vegetation and the degradation of plant communities. A considerable primary literature exists on this topic, therefore it is important to assess whether this accumulated evidence can be used to reach general conclusions concerning vegetation vulnerability to inform conservation management decisions. Experimental trampling studies on a global scale were retrieved using a systematic review methodology and synthesised using random effects meta-analysis. The relationships between vegetation recovery and each of initial vegetation resistance, trampling intensity, time for recovery, Raunkiaer life-form (perennating bud position), and habitat were tested using random effects multiple meta-regressions and subgroup analyses. The systematic search yielded 304 studies; of these, nine reported relevant randomized controlled experiments, providing 188 vegetation recovery effect sizes for analysis. The synthesis indicated there was significant heterogeneity in the impact of trampling on vegetation recovery. This was related to resistance and recovery time, and the interactions of these variables with Raunkiaer life-form, but was not strongly dependent on the intensity of the trampling experienced. The available evidence suggests that vegetation dominated by hemicryptophytes and geophytes recovers from trampling to a greater extent than vegetation dominated by other life-forms. Variation in effect within the chamaephyte, hemicryptophyte and geophyte life-form sub-groups was also explained by the initial resistance of vegetation to trampling, but not by trampling intensity. Intrinsic properties of plant communities appear to be the most important factors determining the response of vegetation to trampling disturbance. Specifically, the dominant Raunkiaer life-form of a plant community accounts for more variation in the resilience of communities to trampling than the intensity of the trampling experienced, suggesting that simple assessments based on this trait could guide decisions concerning sustainable access to natural areas. Methodological and reporting limitations must be overcome before more disparate types of evidence can be synthesised; this would enable more reliable extrapolation to non-study situations, and a more comprehensive understanding of how assessments of intrinsic plant traits can be used to underpin conservation management decisions concerning access.
References
[1]
Andersen UV. 1995. Resistance of Danish coastal vegetation types to human trampling. Biological Conservation 71:223-230
[2]
Andrés-Abellán M, López-Serrano FR, Morote FAG, Cerro-Barja AD. 2006. Assessment of trampling simulation impacts on native vegetation in Mediterranean Sclerophyllous forest. Environmental Monitoring and Assessment 120:93-107
[3]
Bernhardt-Rmermann M, Gray A, Vanbergen AJ, Bergès L, Bohner A, Brooker RW, De Bruyn L, De Cinti B, Dirnbck T, Grandin U, Hester AJ, Kanka R, Klotz S, Loucougaray G, Lundin L, Matteucci G, Mészáros I, Oláh V, Preda E, Prévosto B, Pykl J, Schmidt W, Taylor ME, Vadineanu A, Waldmann T, Stadler J. 2011. Functional traits and local environment predict vegetation responses to disturbance: a pan-European multi-site experiment. Journal of Ecology 99:777-787
[4]
Brookes ST, Whitley E, Peters TJ, Mulheran PA, Egger M, Davey Smith G. 2001. Subgroup analyses in randomised controlled trials: quantifying the risks of false-positives and false-negatives. Health Technology Assessment 5(33):1-56
[5]
Burden RF, Randerson PF. 1972. Quantitative studies of the effects of human trampling on vegetation as an aid to the management of semi-natural areas. Journal of Applied Ecology 9:439-457
[6]
Chappell HG, Ainsworth JF, Cameron RAD, Redfern M. 1971. The effect of trampling on a chalk grassland ecosystem. Journal of Applied Ecology 8:869-882
[7]
Cole DN. 1987. Effects of three seasons of experimental trampling on five montane forest communities and a grassland in western Montana, USA. Biological Conservation 40:219-244
[8]
Cole DN. 1995a. Experimental trampling of vegetation. I. Relationship between trampling intensity and vegetation response. Journal of Applied Ecology 32:203-214
[9]
Cole DN. 1995b. Experimental trampling of vegetation. II. Predictors of resistance and resilience. Journal of Applied Ecology 32:215-224
[10]
Cole DN, Bayfield NG. 1993. Recreational trampling of vegetation: standard experimental procedures. Biological Conservation 63:209-215
[11]
Cole DN, Monz CA. 2002. Trampling disturbance of high-elevation vegetation, Wind river mountains, Wyoming, USA. Arctic, Antarctic, and Alpine Research 34:365-376
[12]
Cole DN, Spildie DR. 1998. Hiker, horse and llama trampling effects on native vegetation in Montana, USA. Journal of Environmental Management 53(1):61-71
[13]
Cooper HM, Hedges LV. 1994. The handbook of research synthesis. New York: Russell Sage Foundation.
[14]
Deeks JJ, Altman DG, Bradburn MJ. 2001. Statistical methods for examining heterogeneity and combining results from several studies in meta-analysis. In: Egger M, Smith GD, Altman D, eds. Systematic reviews in health care: meta-analysis in context. London: John Wiley & Sons. 285-312
[15]
DerSimonian R, Laird N. 1986. Meta-analysis in clinical trials. Controlled Clinical Trials 7:177-188
[16]
Egger M, Davey Smith G, Schneider M, Minder C. 1997. Bias in meta-analysis detected by a simple, graphical test. British Medical Journal 315:629-634
[17]
Egger M, Davey Smith G, Altman D. 2001. Systematic reviews in health care: meta-analysis in context (2nd edition). London: BMJ Books. 487. Available at http://books.google.co.uk/books?id=ErhNdafPCrQC
[18]
Gallet S, Lemauviel S, Rozé F. 2004. Responses of three heathland shrubs to single or repeated experimental trampling. Environmental Management 33:821-829
[19]
Gallet S, Roze F. 2001. Resistance of Atlantic Heathlands to trampling in Brittany (France): influence of vegetation type, season and weather conditions. Biological Conservation 97:189-198
[20]
Gallet S, Rozé F. 2002. Long-term effects of trampling on Atlantic heathland in Brittany (France): resilience and tolerance in relation to season and meteorological conditions. Biological Conservation 103:267-275
[21]
Gurevitch J, Hedges LV. 2001. Meta-analysis: combining the results of independent experiments. In: Scheiner SM, Gurevitch J, eds. Design and analysis of ecological experiments. New York: Oxford University Press. 347-369
[22]
Hedges LV, Tipton E, Johnson MC. 2010. Robust variance estimation in meta-regression with dependent effect size estimates. Research Synthesis Methods 1:39-65
[23]
Hylgaard T. 1980. Recovery of plant communities on coastal sand-dunes disturbed by human trampling. Biological Conservation 19:15-25
[24]
Ikeda H. 2003. Testing the intermediate disturbance hypothesis on species diversity in herbaceous plant communities along a human trampling gradient using a 4-year experiment in an old-field. Ecological Research 18:185-197
[25]
Kattge J, Díaz S, Lavorel S, Prentice IC, Leadley P, Bnisch G, Garnier E, Westoby M, Reich PB, Wright IJ, Cornelissen JHC, Violle C, Harrison SP, Van Bodegom PM, Reichstein M, Enquist BJ, Soudzilovskaia NA, Ackerly DD, Anand M, Atkin O, Bahn M, Baker TR, Baldocchi D, Bekker R, Blanco CC, Blonder B, Bond WJ, Bradstock R, Bunker DE, Casanoves F, Cavender-Bares J, Chambers JQ, Chapin FS, Chave J, Coomes D, Cornwell WK, Craine JM, Dobrin BH, Duarte L, Durka W, Elser J, Esser G, Estiarte M, Fagan WF, Fang J, Fernández-Méndez F, Fidelis A, Finegan B, Flores O, Ford H, Frank D, Freschet GT, Fyllas NM, Gallagher RV, Green WA, Gutierrez AG, Hickler T, Higgins SI, Hodgson JG, Jalili A, Jansen S, Joly CA, Kerkhoff AJ, Kirkup D, Kitajima K, Kleyer M, Klotz S, Knops JMH, Kramer K, Kühn I, Kurokawa H, Laughlin D, Lee TD, Leishman M, Lens F, Lenz T, Lewis SL, Lloyd J, Llusià J, Louault F, Ma S, Mahecha MD, Manning P, Massad T, Medlyn BE, Messier J, Moles AT, Müller SC, Nadrowski K, Naeem S, Niinemets ü, Nllert S, Nüske A, Ogaya R, Oleksyn J, Onipchenko VG, Onoda Y, Ordoez J, Overbeck G, Ozinga WA, Patio S, Paula S, Pausas JG, Peuelas J, Phillips OL, Pillar V, Poorter H, Poorter L, Poschlod P, Prinzing A, Proulx R, Rammig A, Reinsch S, Reu B, Sack L, Salgado-negret B, Sardans J, Shiodera S, Shipley B, Siefert A, Sosinski E, Soussana J-F, Swaine E, Swenson N, Thompson K, Thornton P, Waldram M, Weiher E, White M, White S, Wright SJ, Yguel B, Zaehle S, Zanne AE, Wirth C. 2011. TRY – a global database of plant traits. Global Change Biology 17:2905-2935
[26]
Kent M. 2012. Vegetation description and data analysis: a practical approach (2nd edition). Chichester: Wiley-Blackwell. 428. Available at http://www.amazon.co.uk/dp/0471490938
[27]
Kuss FR. 1986. A review of major factors influencing plant responses to recreation impacts. Environmental Management 10:637-650
[28]
Kuss FR, Graefe AR. 1985. Effects of recreation trampling on natural area vegetation. Journal of Leisure Research 17:165-183
[29]
Kuss FR, Hall CN. 1991. Ground flora trampling studies: five years after closure. Environmental Management 15:715-727
[30]
Leung Y, Marion J. 2000. Recreation impacts and management in wilderness: a state-of-knowledge review. In: Cole D, McCool S, Borrie W, Oloughlin J, eds. Wilderness ecosystems, threats, and management. US Department of Agriculture, Forest Service, Rocky Mountain Research Station, Ogden, UT. 23-48
[31]
Liddle MJ. 1975a. A selective review of the ecological effects of human trampling on natural ecosystems. Biological Conservation 7:17-36
[32]
Liddle MJ. 1975b. A theoretical relationship between the primary productivity of vegetation and its ability to tolerate trampling. Biological Conservation 8:251-255
[33]
Marren P. 2013. Comment: nature versus people: room for both on NNRs? British Wildlife 25:138-139
[34]
Newton AC, Stewart GB, Diaz A, Golicher D, Pullin AS. 2007. Bayesian belief networks as a tool for evidence-based conservation management. Journal for Nature Conservation 15:144-160
[35]
Monz CA, Pokorny T, Freilich J, Kehoe S, Ayers-Baumeister D. 2000. The consequences of trampling disturbance in two vegetation types at the Wyoming Nature Conservancy’s Sweetwater River Project Area. In: Proceedings: wilderness science in a time of change conference. 5:153-159
[36]
Monz CA. 2002. The response of two arctic tundra plant communities to human trampling disturbance. Journal of Environmental Management 64(2):207-217
[37]
Newton AC, Stewart GB, Myers G, Diaz A, Lake S, Bullock JM, Pullin AS. 2009. Impacts of grazing on lowland heathland in north-west Europe. Biological Conservation 142:935-947
[38]
Pullin AS, Knight TM. 2003. Support for decision making in conservation practice: an evidence-based approach. Journal for Nature Conservation 11:83-90
[39]
Pullin AS, Stewart GB. 2006. Guidelines for systematic review in conservation and environmental management. Conservation Biology 20:1647-1656
[40]
R Core Team. 2005. R: a language and environment for statistical computing. R Foundation for Statistical Computing
[41]
Roovers P, Verheyen K, Hermy M, Gulinck H. 2004. Experimental trampling and vegetation recovery in some forest and heathland communities. Applied Vegetation Science 7:111-118
[42]
Ros M, Garcia C, Hernandez T, Andres M, Barja A. 2004. Short-term effects of human trampling on vegetation and soil microbial activity. Communications in Soil Science and Plant Analysis 35:1591-1603
[43]
Rosenthal R. 1991. Meta-analytic procedures for social research. London: Sage Publications.
[44]
Sharp S. 1998. Meta-analysis regression: statistics, biostatistics, and epidemiology. Stata Technical Bulletin 42:16-22
[45]
Stata Corporation. 2003. Stata statistical software. College Station, TX: Stata Corporation.
[46]
Stewart G. 2010. Meta-analysis in applied ecology. Biology Letters 6:78-81
[47]
Stewart GB, Altman DG, Askie LM, Duley L, Simmonds MC, Stewart LA. 2012. Statistical analysis of individual participant data meta-analyses: a comparison of methods and recommendations for practice. PLoS ONE 7:e46042
[48]
Sun D, Walsh D. 1998. Review of studies on environmental impacts of recreation and tourism in Australia. Journal of Environmental Management 53:323-338
[49]
Sutherland WJ, Pullin AS, Dolman PM, Knight TM. 2004. The need for evidence-based conservation. Trends in Ecology & Evolution 19:305-308
[50]
Sutherland WJ, Armstrong-Brown S, Armsworth PR, Brereton T, Brickland J, Campbell CD, Chamberlain DE, Cooke AI, Dulvy NK, Dusic NR, Fitton M, Freckleton RP, Godfray HC, Grout N, Harvey HJ, Hedley C, Hopkins JJ, Kift NB, Kirby J, Kunin WE, MacDonald DW, Markee B, Naura M, Neale AR, Oliver T, Osborn D, Pullin AS, Shardlow MEA, Showler DA, Smith PL, Smithers RJ, Solandt J-L, Spencer J, Spray CJ, Thomas CD, Thompson J, Webb SE, Yalden DW, Watkinson AR. 2006. The identification of 100 ecological questions of high policy relevance in the UK. Journal of Applied Ecology 43:617-627
[51]
Talbot LM, Turton SM, Graham AW. 2003. Trampling resistance of tropical rainforest soils and vegetation in the wet tropics of north east Australia. Journal of Environmental Management 69:63-69
[52]
Taylor KC, Reader RJ, Larson DW. 1993. Scale-dependent inconsistencies in the effects of trampling on a forest understory community. Environmental Management 17:239-248
[53]
Thompson SG, Higgins J. 2002. How should meta-regression analyses be undertaken and interpreted? Statistics in Medicine 21:1559-1573
[54]
Thompson SG, Sharp SJ. 1999. Explaining heterogeneity in meta-analysis: a comparison of methods. Statistics in Medicine 18:2693-2708
[55]
Viechtbauer W. 2010. Conducting meta-analyses in R with the metafor package. Journal of Statistical Software 36:1-48
[56]
Violle C, Navas M-L, Vile D, Kazakou E, Fortunel C, Hummel I, Garnier E. 2007. Let the concept of trait be functional! Oikos 116:882-892
[57]
Yorks T, West N, Mueller R, Warren S. 1997. Toleration of traffic by vegetation: life form conclusions and summary extracts from a comprehensive data base. Environmental Management 21:121-131
[58]
Zuur AF, Ieno EN, Elphick CS. 2010. A protocol for data exploration to avoid common statistical problems. Methods in Ecology and Evolution 1:3-14
