Abstract
Georgia is known for its extraordinary rich biodiversity of plants, which may now be threatened due to the spread of invasive alien plants (IAP). We aimed to identify (1) the most prominent IAP out of 9 selected potentially invasive and harmful IAP by predicting their distribution under current and future climate conditions in Georgia as well as in its 43 Protected Areas, as a proxy for areas of high conservation value and (2) the Protected Areas most at risk due to these IAP. We used species distribution models based on 6 climate variables and then filtered the obtained distributions based on maps of soil and vegetation types, and on recorded occurrences, resulting into the predicted ecological distribution of the 9 IAP’sat a resolution of 1 km2. Our habitat suitability analysis showed that Ambrosia artemisiifolia, (24 and 40 %) Robinia pseudoacaia (14 and 19 %) and Ailanthus altissima (9 and 11 %) have the largest potential distribution (predicted % area covered), with A. altissima the potentially most increasing one over the next 50 years (from 9 to 13 % and from 11 to 25 %), for Georgia and the Protected Areas, respectively. Furthermore, our results indicate two areas in Georgia that are under specifically high threat, i.e. the area around Tbilisi and an area in the western part of Georgia (Adjara), both at lower altitudes. Our procedure to identify areas of high conservation value most at risk by IAP has been applied for the first time. It will help national authorities in prioritizing their measures to protect Georgia’s outstanding biodiversity from the negative impact of IAP.
Similar content being viewed by others
References
Alexander JM, Kueffer C, Daehler CC, Edwards PJ, Pauchard A, Seipel T, Consortium M (2011) Assembly of nonnative floras along elevational gradients explained by directional ecological filtering. Proc Natl Acad Sci 108:656–661
Allouche O, Tsoar A, Kadmon RO (2006) Assessing the accuracy of species distribution models: prevalence, kappa and the true skill statistic (TSS). J Appl Ecol 43:1223–1232
Anonymous (2009) Agency of Protected Areas Georgia. Ministry of Environmental Protection and Natural Resources of Georgia. www.apa.gov.ge
Anonymous (2012) Conservation international. www.conservation.org
Anonymous (2012) ELAW, Environmental law alliance worldwide. www.elaw.org/node/1327
Anonymous (2012) IUCN, International union for conservation of nature. www.iucn.org
Anonymous (2012) WorldClim global climate data. www.worldclim.org
Anonymous (2012) WWF, world wildlife found. www.panda.org
Araújo MB, Guisan A (2006) Five (or so) challenges for species distribution modelling. J Biogeogr 33:1677–1688
Araújo MB, Whittaker RJ, Ladle RJ, Erhard M (2005) Reducing uncertainty in projections of extinction risk from climate change. Glob Chang Biol 14:529–538
Bartlein PJ, Prentice IC, Webb T (1986) Climatic response surfaces from pollen data for some eastern North American taxa. J Biogeogr 13:35–57
Barve N, Barve V, Jiménez-Valverde A, Lira-Noriega A, Maher SP, Townsend Peterson A, Soberón J, Villalobos F (2011) The crucial role of the accessible area in ecological niche modeling and species distribution modelling. Ecol Model 11:1810–1819
Beaumont LJ, Gallagher RV, Thuiller W, Downey PO, Leishman MR, Hughes L (2009) Different climatic envelopes among invasive populations may lead to underestimations of current and future biological invasions. Divers Distrib 15:409–420
Blackburn TM, Pyšek P, Bacher S, Carlton JT, Duncan RP, Jarošík V, Wilson JRU, Richardson DM (2011) A proposed unified framework for biological invasions. Trends Ecol Evol 26:333–339
Bohn U, Gollub G, Hettwer C, Neuhäuslová Z, Raus TH, Schlüter H, Weber H (2004) Karte der natürlichen Vegetation Europas/Map of the Natural Vegetation of Europe, Maßstab/Scale 1:2.500.000, Interaktive/Interactive CD-ROM- Erläuterungstext, Legende, Karten/Explanatory Text, Legend, Maps. Landwirtschaftsverlag, Münster
Boyce MS, Vernier PR, Nielsen SE, Schmiegelow FKA (2002) Evaluating resource selection functions. Ecol Model 157:281–300
Breiman L (2001) Random forests. Mach Learn 45:5–32
Broennimann O, Guisan A (2008) Predicting current and future biological invasions: both native and invaded range matters. Biol Lett 4:585–589
Broennimann O, Treier UA, Müller-Schärer H, Thuiller W, Peterson AT, Guisan A (2007) Evidence of niche shift during biological invasion. Ecol Lett 10:701–709
Brooks TM, Mittermeier RA, da Fonseca GAB, Gerlach J, Hoffmann M, Lamoreux JF, Mittermeier CG, Pilgrim JD, Rodrigues ASL (2006) Global biodiversity conservation priorities. Science 313:58–61
Bustamante J, Seoane J (2004) Predicting the distribution of four species of raptors (Aves: Accipitridae) in southern Spain: statistical models work better than existing maps. J Biogeogr 31:295–306
Cacho O, Hester S, Spring D (2007) Applying search theory to determine the feasibility of eradicating an invasive population in natural environments. Aust J Agric Resour Econ 51:425–443
Chen IC, Hill JK, Ohlemuller R, Roy DB, Thomas CD (2011) Rapid range shifts of species associated with high levels of climate warming. Science 333:1024–1026
Cousins MM, Briggs J, Gresham C, Whetstone J, Whitwell T (2010) Beach Vitex (Vitex rotundifolia): an invasive costal species. Invasive Plant Species Manag 3:340–345
Dirnbock T, Greimler J, Lopez P, Stuessy TF (2003) Predicting future threats to the native vegetation of Robinson Crusoe Island, Juan Fernandez Archipelago, Chile. Conserv Biol 17:1650–1659
Dudley N (ed.) (2008) Guidelines for applying protected area management categories. Gland, Switzerland: IUCN. x + 86 pp. ISBN: 978-2-8317-1086-0
Ehrenfeld JG (2010) Ecosystem consequences of biological invasions. Annu Rev Ecol Evol Syst 41:59–80
Epanchin-Niell RS, Hastings A (2010) Controlling established invaders: integrating economics and spread dynamics to determine optimal management. Ecol Lett 13:528–541
EPPO, European and Mediterranean Plant protection Organisation (2014) www.eppo.int
Friedman JH (2001) Greedy function approximation: a gradient boosting machine. Ann Stat 29:1189–1232
Guisan A, Rahbek C (2011) SESAM—a new framework integrating macroecological and species distribution models for predicting spatio-temporal patterns of species assemblages. J Biogeogr 38:1433–1444
Guisan A, Thuiller W (2005) Predicting species distribution: offering more than simple habitat models. Ecol Lett 8:993–1009
Guisan A, Tingley R, Baumgartner JB, Naujokaitis-Lewis I, Sutcliffe PR, Tulloch AIT, Regan TJ, Brotons L, McDonald-Madden E, Mantyka-Pringle C, Martin TG, Rhodes JR, Maggini R, Setterfield SA, Elith J, Schwartz MW, Wintle BA, Broennimann O, Austin M, Ferrier S, Kearney MR, Possingham HP, Buckley YM (2013) Predicting species distributions for conservation decisions. Ecol Lett 16:1424–1435
Gurevitch J, Fox GA, Wardle GM, Inderjit, Taub D (2011) Emergent insights from the synthesis of conceptual frameworks for biological invasions. Ecol Lett 14:407–418
Hellmann JJ, Byers JE, Bierwagen BG, Dukes JS (2008) Five potential consequences of climate change for invasive species. Conserv Biol 22:534–543
Hijmans RJ, Cameron SE, Parra JL, Jones PG, Jarvis A (2005) Very high resolution interpolated climate surfaces for global land areas. Int J Climatol 25:1965–1978
Hirzel AH, Le Lay G, Helfer V, Randin C, Guisan A (2006) Evaluating the ability of habitat suitability models to predict species presences. Ecol Model 199:142–152
IPCC Climate Change (2007) The physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Cambridge
Kikodze A, Gokhelashvili R (eds.) (2007) Protected Areas of Georgia. Tbilisi. Report for the Swiss federal Office of the Environment, p. 37
Kikodze D, Memiadze N, Kharazishvili D, Manvelidze Z, Müller-Schärer H (2010) The alien flora of Georgia
Leung B, Roura-Pascual N, Bacher S, Heikkilä J, Brotons L, Burgman MA, Dehnen-Schmutz K, Essl F, Hulme PE, Richardson DM, Sol D, Vilà M (2012) TEASIng apart alien species risk assessments: a framework for best practices. Ecol Lett 15:1475–1493
Mittermeier RA, Gil PR, Hoffman M, Pilgrim J, Brooks T, Mittermeier CG, Lamoreux J, Da Fonseca GAB (2005) Hotspots revisited: earth’s biologically richest and most endangered terrestrial ecoregions. Conservation International, Washington, p 392
Mittermeier RA, Turner WR, Larsen FW, Brooks TM, Gascon C (2012) Global biodiversity conservation? The critical role of hotspots. In: Zachos FE, Habel JC (eds) Biodiversity hotspots distribution and protection of conservation priority areas. Springer, Berlin, Heidelberg, pp 3–22
Müller-Schärer H, Collins AR (2012) Integrated weed management. In: Jorgensen SE (ed) Encyclopedia of environmental management. Taylor and Francis, New York
Nogues-Bravo D, Rahbek C (2011) Communities under climate change. Science 334:1070–1071
Parker IM, Simberloff D, Lonsdale WM, Goodell K, Wonham M, Kareiva PM, Williamson MH, Von Holle B, Moyle PB, Byers JE, Goldwasser L (1999) Impact: toward a framework for understanding the ecological effects of invaders. Biol Invasions 1:3–19
Pauchard A, Kueffer C, Dietz H, Daehler CC, Alexander J, Edwards PJ, Arévalo JR, Billeter R, Cavieres L, Guisan A, Haider S, Jakobs G, Mack RN, McDougall K, Millar C, Naylor BJ, Parks C, Poll M, Rew LJ, Seipel T (2009) Ain’t no mountain high enough: plant invasions reaching high elevations. Front Ecol Environ 7:479–486
Pereira HM, Leadley PW, Proença V, Alkemade R, Scharlemann JPW, Fernandez-Manjarrés JF, Araújo MB, Balvanera P, Biggs R, Cheung WWL, Chini L, Cooper HD, Gilman EL, Guénette S, Hurtt GC, Huntington HP, Mace GM, Oberdorff T, Revenga C, Rodrigues P, Scholes RJ, Sumaila UR, Walpole M (2010) Scenarios for global biodiversity in the 21st century. Science 330:1496–1501
Petitpierre B, Kueffer C, Broennimann O, Randin C, Daehler C, Guisan A (2012) Climatic niche shifts are rare among terrestrial plant invaders. Science 335:1344–1348
Phillips SJ, Dudik M (2008) Modeling of species distributions with Maxent: new extensions and a comprehensive evaluation. Ecography 31:161–175
Phillips SJ, Andersonb RP, Schapire RP (2006) Maximum entropy modelling of species geographic distributions. Ecol Model 190:231–259
Pyšek P, Jarošík V, Hulme PE, Pergl J, Hejda M, Schaffner, Vilà M (2012) A global assessment of invasive plant impacts on resident species, communities and ecosystems: the interaction of impact measures, invading species’ traits and environment. Glob Chang Biol 18:1725–1737
R Development Core Team (2011) R: a language and environment for statistical computing, 3-900051-07-0R
Richardson DM, Pyšek P, Rejmánek M, Barbour MG, Panetta FD, West CJ (2000) Naturalization and invasion of alien plants: concepts and definitions. Divers Distrib 6(2):93–107
Richter R, Berger UE, Dullinger S, Essl F, Leitner M, Smith M, Vogl G (2013) Spread of invasive ragweed: climate change, management and how to reduce allergy costs. J Appl Ecol 50(6):1422–1430
Rodriguez JP, Brotons L, Bustamante J, Seoane J (2007) The application of predictive modelling of species distribution to biodiversity conservation. Divers Distrib 13:243–251
Seipel T, Kueffer C, Rew L, Daehler C, Pauchard A, Naylor B, Alexander JM, Edwards PJ, Parks CG, Arevalo J, Cavieres L, Dietz H, Jakobs G, McDougall K, Otto R, Walsh N (2012) Processes at multiple spatial scales determine non-native plant species richness and similarity in mountain regions around the world. Glob Ecol Biogeogr 21:236–246
Sun Y, Collins AR, Schaffner U, Müller-Schärer H (2013) Dissecting impact of plant invaders: do invaders behave differently in the new range? Ecology 94:2124–2130
Thuiller W, Richardson DM, Pysek P, Midgley GF, Hughes GO, Rouget M (2005) Niche-based modelling as a tool for predicting the risk of alien plant invasions at a global scale. Glob Chang Biol 11:2234–2250
ThuillerW Lafourcade B, Engler R, Araújo B (2009) BIOMOD—a platform for ensemble forecasting of species distributions. Ecography 32:369–373
Vicente J, Randin CF, Goncalves J, Metzger MJ, Lomba A, Honrado J, Guisan A (2011) Where will conflicts between alien and rare species occur after climate and land-use change? A test with a novel combined modelling approach. Biol Invasions 13:1209–1227
Vilà M, Espinar JL, Hejda M, Hulme PE, Jarošík V, Maron JL, Pergl J, Schaffner U, Sun Y, Pyšek P (2011) Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems. Ecol Lett 14:702–708
Acknowledgments
We greatly acknowledge Grigol Deisadze and Sandro Kolbai for help with field work, Giorgi Mikeladze for supplying the excellent environmental data for the filters and Dr. Shalva Sikharulidze and Maia Tavartkiladze for hosting us during our research stay at the Tbilisi Botanical Garden. We also thank Info Flora for providing the occurrence data of the nine study species in Switzerland and two anonymous reviewers for the helpful and constructive comments on an earlier version of this manuscript. The study was financially supported by a travel grant for botanical, zoological and earth sciences studies from the Swiss Academy of Science, sc.nat + to DT, and by the NCCR Plant Survival, a research program of the Swiss National Science Foundation, to HMS and OB for travelling to Georgia in 2012.
Author information
Authors and Affiliations
Corresponding author
Additional information
Olivier Broennimann and Heinz Müller-Schärer are joint senior authors.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Thalmann, D.J.K., Kikodze, D., Khutsishvili, M. et al. Areas of high conservation value in Georgia: present and future threats by invasive alien plants. Biol Invasions 17, 1041–1054 (2015). https://doi.org/10.1007/s10530-014-0774-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10530-014-0774-2