Analysis of Fragmentation Processes in High-Mountain Forests of the Centre of Mexico
- 1 Instituto de Ciencias Agropecuarias y Rurales, Toluca, México
- 2 Universidad Autónoma Metropolitana, D. F. México, México
- 3 Instituto de Ciencias Agropecuarias y Rurales, Toluca, México
- 4 Instituto de Ciencias Agropecuarias y Rurales, Toluca, México
Abstract
High-mountain forests (>3500 masl) are the main supplier of environmental services to Mexico City and its metropolitan area. Taking as a study case the Nevado de Toluca National Park, this article focuses on the considerable reduction on the density of its forest cover, characterised by disturbances in the structure and dynamics of Pinus hartwegii . This specie is located towards the upper limits of the altitudinal gradient (3500 - 4100 masl) constituting the only pine species in the world capable to be established in those extreme environmental conditions. The information was collected through the implementation of 30 Sampling Plots (SP) of 20 × 50 mts ( 1000 m 2 ) in three forest density categories: dense, semi-dense and fragmented. For each forest category, all trees ≥ 2.5 cm DBH were measured in 10 SPs. The measurement variables were DBH, total and commercial height, forest health and forest extraction. The results show the abundance of dense, semi-dense and fragmented forest (336, 202 and 150 trees /Ha -1 ), with extraction percentages of 11%, 20% and 33% respectively. The horizontal structure distribution shows the shape of an inverted J for the three conditions. However, the phytosanitary conditions of the semi-dense forests (83% infested trees) and fragmented (63% infested trees), do not guaranties the survival of the adult trees, implying an intensification of the fragmentation process for the next decade; given the reduction of the regeneration patterns due to the lack of healthy tree breeding.
- J. A. Encina, F. J. Encina, E. Matarocha and J. I. Valdez, “Aspectos Estructurales, Composición Florística y Caracterización Ecológica del Bosque de Oyamel de la Sierra de Zapalinamé, Coahuila, México,” Boletín del a Sociedad Botánica de México, Vol. 83, 2008, pp. 13-24.
- Y. Vázquez, and S. A. Orozco, “La Destrucción de la Naturaleza,” Fondo de Cultura Económica, México, 1989.
- L. Villers-Ruiz, L. García del Valle and J. López-Blanco, “Evaluación de los Bosques Templados en México: Una Aplicación en el Parque Nacional Nevado de Toluca,” Investigaciones Geográficas, Vol. 36, 1998, pp. 7-21.
- J. Hitimana, J. L. Kiyiapi and J. T. Njunge, “Forest Structure Characteristics in Disturbed and Undisturbed Sites of Mt. Elgon Moist Lower Montane Forest, Western Kenya,” Forest Ecology and Management, Vol. 194, No. 1-3, 2004, pp. 269-291. doi:10.1016/j.foreco.2004.02.025
- C. Cannon, D. R. Peart and M. Leighton, “Tree Species Diversity on Commercially Logged Bornean Rainforest,” Science, Vol. 281, No. 5381, 1998, pp. 1366-1368. doi:10.1126/science.281.5381.1366
- W. Laurance, H. Nascimento, S. G. Laurance, A. C. Andrade, P. M. Fearnside, J. E. L. Ribeiro and R. L. Capretz, “Rain Forest Fragmentation and the Proliferation of Successional Trees,” Ecology, Vol. 87, No. 2, 2006, pp. 469-482. doi:10.1890/05-0064
- R. Bustamante, J. A. Simoneti, A. A. Grez and J. San Martín, “Fragmentación y Dinámica de Regeneración del Bosque Maulino: Diagnostico Actual y Perspectivas Futuras,” 2005, pp. 529-539.
- M. Wulder, J. C. White, M. E. Andrew, N. E. Seitz and N. C. Coops, “Forest Fragmentation, Structure, and Age Characteristics a Legacy of Forest Management,” Forest Ecology and Management, Vol. 258, No. 9, 2009, pp. 1938-1949. doi:10.1016/j.foreco.2009.07.041
- A. Endara, S. Franco, G. Nava, J. I. Valdez and T. Fredericksen, “Effect of Human Disturbance on the Structure and Regeneration of Forests in the Nevado de Toluca National Park, Mexico,” Journal of Forestry Research, Vol. 1, No. 23, 2012, pp. 39-44.
- S. Franco, H. H. Regil and J. A. B. Ordonez, “Dinámica de Perturbación-Recuperación de las Zonas Forestales en el Parque Nacional Nevado de Toluca,” Madera y Bosques, Vol. 1, No. 12, 2006, pp. 17-28.
- E. Villavicencio and J. I. Valdez, “Análisis de la Estructura Arbórea del Sistema Agroforestal Rusticano de Café en San Miguel, Veracruz, México,” Agrociencia, Vol. 4, No. 37, 2003, pp. 413-423.