It is argued that forest fragmentation has negative effects on biodiversity at the short and long term; however, these effects might be dependent on the specific vegetation of the study area and its intrinsic characteristics. The processes leading to fragmentation are very diverse and many of them have anthropogenic causes as logging actions and clearings for agricultural fields. Furthermore, it is thought that scale plays an important role in the expected effects of fragmentation on biodiversity. In this study the effect of forest fragmentation and its impact on the woody plants species, richness and diversity are analysed considering three vegetation types in a poorly studied and difficult access biodiversity hotspot in northern Mexico. The results show that the effects of fragmentation are dependent on the vegetation type and that these are not strongly related to the species richness, and diversity in a microscale (100？m2). Fragmentation effects on biodiversity must be analysed in a broad scale, considering the fragment as a whole. Furthermore, conservation priority should be given to the larger fragments, which could potentially maintain a higher portion of biodiversity. Management should also be focused on increasing the connectivity between these big and medium size forest patches. 1. Introduction The processes generating forest loss and habitat fragmentation are recognized as a principal cause of biodiversity decline and are the greatest ecological problem in tropical developing countries [1–6]. These processes increase the vulnerability of the species that inhabit the forest ecosystem by reducing the suitable habitat and by generating patch isolation [7, 8]. Thus, habitat loss and fragmentation are usually perceived as having negative effects on biodiversity (i.e., [9, 10]) due to the reduction in area available, which decreases the species’ effective population sizes, and to the increase in the number of smaller forest fragments, which also modify the microenvironmental characteristics of the landscape. However, there are studies that claim that forest fragmentation can have positive [11, 12] or even inconsistent effects [13], depending on the species analysed and the landscape size and structure. It is argued that larger fragments might contain more species than small fragments and that when the patch’s area decreases, it has higher implications for core area species than for the edge ones. However, also contradictory results have been obtained (i.e., [14–16]) reflecting the need of more information resulting from field-based studies carried
References
[1]
G. ？akir, F. Sivrikaya, and S. Kele？, “Forest cover change and fragmentation using Landsat data in Ma？ka State Forest Enterprise in Turkey,” Environmental Monitoring and Assessment, vol. 137, no. 1, pp. 51–66, 2008.
[2]
L. D. Harris, The Fragmented Forest: Island Biogeography Theory and the Preservation of Biotic Diversity, University of Chicago Press, 1984.
[3]
S. Kilic, F. Evrendilek, S. Berberoglu, and A. C. Demirkesen, “Environmental monitoring of land-use and land-cover changes in a Mediterranean Region of Turkey,” Environmental Monitoring and Assessment, vol. 114, no. 1–3, pp. 157–168, 2006.
[4]
W. F. Laurance, “Reflections on the tropical deforestation crisis,” Biological Conservation, vol. 91, no. 2-3, pp. 109–117, 1999.
[5]
K. S. Rao and R. Pant, “Land use dynamics and landscape change pattern in a typical micro watershed in the mid elevation zone of central Himalaya, India,” Agriculture, Ecosystems and Environment, vol. 86, no. 2, pp. 113–124, 2001.
[6]
W. D. Robinson and T. W. Sherry, “Mechanisms of avian population decline and species loss in tropical forest fragments,” Journal of Ornithology, vol. 153, no. 1, pp. 141–152, 2012.
[7]
A. Farina, Principles and Methods in Landscape Ecology, Springer, New York, NY, USA, 2006.
[8]
M. G. Turner, R. H. Gardner, and R. V. O'Neill, Landscape Ecology in Theory and Practice: Pattern and Process, Springer, New York, NY, USA, 2001.
[9]
Y. Haila, “A conceptual genealogy of fragmentation research: from island biogeography to landscape ecology,” Ecological Applications, vol. 12, no. 2, pp. 321–334, 2002.
[10]
D. Urban and T. Keitt, “Landscape connectivity: a graph-theoretic perspective,” Ecology, vol. 82, no. 5, pp. 1205–1218, 2001.
[11]
K. Ethier and L. Fahrig, “Positive effects of forest fragmentation, independent of forest amount, on bat abundance in eastern Ontario, Canada,” Landscape Ecology, vol. 26, no. 6, pp. 865–876, 2011.
[12]
A. C. Smith, L. Fahrig, and C. M. Francis, “Landscape size affects the relative importance of habitat amount, habitat fragmentation, and matrix quality on forest birds,” Ecography, vol. 34, no. 1, pp. 103–113, 2011.
[13]
M. Schleuning, N. Farwig, M. K. Peters et al., “Forest fragmentation and selective logging have inconsistent effects on multiple animal-mediated ecosystem processes in a tropical forest,” PLoS ONE, vol. 6, no. 11, Article ID e27785, 2011.
[14]
H. Jacquemyn, R. Brys, and M. Hermy, “Patch occupancy, population size and reproductive success of a forest herb (Primula elatior) in a fragmented landscape,” Oecologia, vol. 130, no. 4, pp. 617–625, 2002.
[15]
S. Ochoa-Gaona, M. González-Espinosa, J. A. Meave, and V. S. Bon, “Effect of forest fragmentation on the woody flora of the highlands of Chiapas, Mexico,” Biodiversity and Conservation, vol. 13, no. 5, pp. 867–884, 2004.
[16]
S. Petit, L. Griffiths, S. S. Smart, G. M. Smith, R. C. Stuart, and S. M. Wright, “Effects of area and isolation of woodland patches on herbaceous plant species richness across Great Britain,” Landscape Ecology, vol. 19, no. 5, pp. 463–472, 2004.
[17]
J. S. Markl, M. Schleuning, P. M. Forget et al., “Meta-analysis of the effects of human disturbance on seed dispersal by animals,” Conservation Biology, vol. 26, no. 6, pp. 1072–1081, 2012.
[18]
J. K. Hill, M. A. Gray, C. V. Khen, S. Benedick, N. Tawatao, and K. C. Hamer, “Ecological impacts of tropical forest fragmentation: how consistent are patterns in species richness and nestedness?” Philosophical Transactions of the Royal Society B, vol. 366, no. 1582, pp. 3265–3276, 2011.
[19]
S. P. Hubbell, The Unified Neutral Theory of Biodiversity and Biogeography, Princeton University Press, Princeton, NJ, USA, 2001.
[20]
I. M. Turner and R. T. Corlett, “The conservation value of small, isolated fragments of lowland tropical rain forest,” Trends in Ecology and Evolution, vol. 11, no. 8, pp. 330–333, 1996.
[21]
A. Aparicio, R. G. Albaladejo, M. á. Olalla-Tárraga, L. F. Carrillo, and M. á. Rodríguez, “Dispersal potentials determine responses of woody plant species richness to environmental factors in fragmented Mediterranean landscapes,” Forest Ecology and Management, vol. 255, no. 7, pp. 2894–2906, 2008.
[22]
M. J. Struebig, T. Kingston, E. J. Petit et al., “Parallel declines in species and genetic diversity in tropical forest fragments,” Ecology Letters, vol. 14, no. 6, pp. 582–590, 2011.
[23]
J. C. Biesmeijer, S. P. M. Roberts, M. Reemer et al., “Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands,” Science, vol. 313, no. 5785, pp. 351–354, 2006.
[24]
M. Gonzalez, M. Deconchat, and G. Balent, “Woody plant composition of forest layers: the importance of environmental conditions and spatial configuration,” Plant Ecology, vol. 201, no. 1, pp. 305–318, 2009.
[25]
E. Weiher and A. Howe, “Scale-dependence of environmental effects on species richness in oak savannas,” Journal of Vegetation Science, vol. 14, no. 6, pp. 917–920, 2003.
[26]
CIF, Conservation International Foundation, 2009.
[27]
L. Arriaga, J. M. Espinoza, C. Aguilar, E. Martínez, L. Gómez, and E. Loa, Regiones terrestres prioritarias de México, Comisión Nacional para el Conocimiento y uso de la Biodiversidad, Mexico City, Mexico, 2000, http://www.conabio.gob.mx/conocimiento/regionalizacion/doctos/Tlistado.html.
[28]
INEGI (Instituto Nacional de Estadística Geografía e Informática), Fuente del sitio en internet, 2010, http://www.inegi.org.mx/.
[29]
ESRI, ESRI, Redlands, Calif, USA, 2012.
[30]
J. Aguirre-Gutiérrez, A. C. Seijmonsbergen, and J. F. Duivenvoorden, “Optimizing land cover classification accuracy for change detection, a combined pixel-based and object-based approach in a mountainous area in Mexico,” Applied Geography, vol. 34, pp. 29–37, 2012.
[31]
K. McGarigal, S. A. Cushman, M. C. Neel, and E. Ene, FRAGSTATS: Spatial Pattern Analysis Program for Categorical Maps, Computer software program the University of Massachusetts, Amherst, Mass, USA, 2002, http://www.umass.edu/landeco/research/fragstats/fragstats.html.
[32]
H. L. Beyer, Hawth's Analysis Tools for ArcGIS, 2004, http://www.spatialecology.com/htools.
[33]
E. Wakild, “Environment and environmentalism,” in A Companion to Mexican History and Culture, W. H. Beezley, Ed., pp. 518–537, Wiley-Blackwell, Oxford, UK, 2011.
[34]
F. B. Zu？iga, Técnicas de muestreo para manejadores de recursos naturales, Instituto Nacional de Ecología, 2004.
[35]
A. Farjon and B. T. Styles, Pinus (Pinaceae), vol. 75, Botanical Garden Press, New York, NY, USA, 1997.
[36]
A. Farjon, J. A. P. de la Rosa, and B. T. Styles, Guía de campo de los Pinos de México y América Central, Royal Botanic Gardens, Kew, London, UK, 2000.
[37]
D. M. Richardson, Ecology and Biogeography of Pinus, Cambridge University Press, Cambridge, UK, 1998.
[38]
Garmin, Etrex, HC, Garmin International Inc., Olathe Kan, USA, 2010.
[39]
I. T. Galanes and J. R. Thomlinson, “Relationships between spatial configuration of tropical forest patches and woody plant diversity in northeastern Puerto Rico,” Plant Ecology, vol. 201, no. 1, pp. 101–113, 2009.
[40]
A. Martínez-Morales, “Landscape patterns influencing bird assemblages in a fragmented neotropical cloud forest,” Biological Conservation, vol. 121, no. 1, pp. 117–126, 2005.
[41]
S. Ochoa-Gaona, “Traditional land-use systems and patterns of forest fragmentation in the highlands of Chiapas, Mexico,” Environmental Management, vol. 27, no. 4, pp. 571–586, 2001.
[42]
R. S. Rempel, D. Kaukinen, and A. P. Carr, Patch Analyst and Patch Grid, Ontario Ministry of Natural Resources, Centre for Northern Forest Ecosystem Research, Thunder Bay, Canada, 2012.
[43]
A. F. Zuur, E. N. Ieno, N. J. Walker, A. A. Saveliev, and G. M. Smith, Mixed Effects Models and Extensions in Ecology with R, Springer, New York, NY, USA, 2009.
[44]
R Development Core Team, R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing, Vienna, Austria, 2013, http://www.r-project.org/.
[45]
J. Oksanen, F. Guillaume, R. Kindt et al., “Vegan: community,” Ecology Package, R package version 1.17-3, 2010, http://cran.r-project.org/package=vegan.
[46]
P. Legendre and L. Legendre, Numerical Ecology, Elsevier, New York, NY, USA, 1998.
[47]
D. A. Jackson, “Stopping rules in principal components analysis: a comparison of heuristical and statistical approaches,” Ecology, vol. 74, no. 8, pp. 2204–2214, 1993.
[48]
C. Echeverría, A. C. Newton, A. Lara, J. M. R. Benayas, and D. A. Coomes, “Impacts of forest fragmentation on species composition and forest structure in the temperate landscape of southern Chile,” Global Ecology and Biogeography, vol. 16, no. 4, pp. 426–439, 2007.
[49]
L. Cayuela, J. M. R. Benayas, and C. Echeverría, “Clearance and fragmentation of tropical montane forests in the Highlands of Chiapas, Mexico (1975-2000),” Forest Ecology and Management, vol. 226, no. 1–3, pp. 208–218, 2006.
[50]
R. Gingrich, “Building effective international, multicultural alliances for restoration of ejido forests in the Sierra Madre Occidental,” in Proceedings of the Connecting Mountain Islands and Desert Seas: Biodiversity and Management of the Madrean Archipelago II and 5th Conference on Research and Resource Management in the Southwestern Deserts, Tucson, Ariz, USA, May 2005.
