Tropical Mexico's Recent Land-Use Change: A Region's Contribution to the Global Carbon Cycle

Abstract

We applied modeled biomass density estimates to changes in land use/land cover (LU/LC) statistics for the intensively impacted and highly fragmented landscape of tropical Mexico to estimate the flux of carbon (C) between terrestrial ecosystems and the atmosphere between 1977 and 1992. Biomass densities were assigned to hybrid LU/LC classes on vegetation maps produced by Mexican governmental organizations and, by differencing areas and biomass C pools, net C flux was calculated in the eight-state tropical region of southeast Mexico. These states, representing tropical Mexico, experienced a mean annual deforestation rate of nearly 559 000 ha/yr, or 1.9%, between 1977 and 1992. The total area of closed forests decreased by 26%, open/fragmented forests decreased by 31%, and agroecosystem areas increased by 64%. Total mean biomass densities ranged from a high of 265 Mg/ha in the Veracruz state tall/medium tropical evergreen forest class to a low of 12 Mg/ha in the cultivated land class (several states). We estimate that a total of 280 Tg C were released from the terrestrial biosphere during the 15-yr period covered by our study, equal to nearly 20% of the region's 1977 biomass C pool. The study region, while comprising just 24% of Mexico's surface area, contributed 36% of the net national C emissions from LU/LC change.

Effect of anthropogenic disturbances on biomass and carbon storage potential of a dry tropical forest in India

“…Delaney et al (1997) reported 285 Mg ha -1 above ground biomass of Venezuela Tropical moist forest. The above ground biomass is very similar to Cairns et al (2000) for the semi-evergreen forest of Yucatan Peninsula (111.2 Mg ha -1 ), but less than the Veracruz (225.8 Mg ha -1 ). Brown et al (1995) and Golley et al (1975) Singh et al (2009).…”

Population genetic structure of orchid bees (Euglossini) in anthropogenically altered landscapes

“…This forest area is isolated from other lowland tropical forests by a broad belt ([130 km) of intensively used land dominated by pastures and cash crops. The ecological isolation of Los Tuxtlas forests on this scale has existed for at least 35 years [see maps in Cairns et al (2000)] but most likely since the 1950s, when extensive transformations of natural habitats to mostly cattle ranches began (Mendoza et al 2005). Localities B and C are in an area of larger forest remains beyond that belt of farmland, flanking the northeastern slopes of the central cordillera in western Veracruz/eastern Oaxaca.…”

“…1) in southern Mexico. Between 1977 and 1992 tropical Mexico experienced a reduction of about 28% of its total forest area, resulting in a highly disturbed landscape that includes cultivated land, secondary forest, grazing lands, and disturbed forests (Cairns et al 2000). Locality A is near the Biological Station ''Los Tuxtlas'', situated in the northeastern lowland part (18°30 0 N, 95°8 0 W) of the biosphere reserve Los Tuxtlas (Volcán San Martín) in the state of Veracruz.…”

Linking local vulnerability to system sustainability in a resilience framework: two cases from Latin America

“…Mexico's cloud forests are already fragmented, and researchers attribute a significant net release of carbon into the atmosphere to the conversion of both undisturbed and disturbed forest in Veracruz into open agricultural use (Cairns et al 2000). Here, the investment of individual smallholders in agroforestry and sustainable coffee farming could have a larger-scale positive impact on local and regional ecosystem functions (Pineda-López et al 2005).…”