Challenging the linear forestation narrative in the Neo‐tropic: regional patterns and processes of deforestation and regeneration in southern Mexico

Abstract

In the Neotropics increased rates of land use and land cover change (LULCC) and a strong deforestation trend in the second half of the twentieth century have caused environmental degradation and biodiversity loss. This study analysed patterns and processes of LULCC and deforestation for the Grijalva–Usumacinta watershed, one of the hydrologically and biologically most important watersheds in southern Mexico in face of the discussion about beginning forest transitions in the Neotropics. Maps of land use and land cover for 1992, 2002 and 2007 derived from satellite and aerial imagery were analysed to test the hypothesis of changing trends on a regional scale. Change rates and probabilities were calculated for two time periods and dominant LULCC processes were identified. LULCC is complex and cannot be explained by the predominant linear deforestation narrative alone. A crucial finding was an unusually high rate of forest degradation for all primary forest types, being 1.7 times the area of forest deforestation; and that deforestation processes occur mainly in secondary forests. Agricultural activities fostered by public policies are the principal drivers for LULCC, among which pastures have the highest impact on deforestation. Deforestation and LULCC rates and probabilities have stagnated, and natural reforestation has increased. Although these trends are essential for the onset of forest transition, deforestation and degradation outweigh by far vegetation regrowth.

Highly diversified coronaviruses in neotropical bats

“…However, the growing invasion and destruction of neotropical habitats (Dale et al, 1994;Kolb & Galicia, 2012) may provide further exposure of humans to bats and their viruses, as exemplified by the emergence of Nipah virus in 1998 (Daszak et al, 2001;Keesing et al, 2010 The diversified ecology, a high number of co-existing bat species and their local abundance in relation to other mammalian species (Rex et al, 2008), could make neotropical bats a leading receiver and spreader of viruses in neotropical ecosystems. For example, sanguivorous bats only exist in the Neotropics and could hypothetically facilitate viral host switches between bats and other mammals.…”

Análisis del cambio de uso del suelo en un ecosistema urbano en la zona de drenaje del río Grijalva, México

“…In the decade of the 70's, the beginning of the oil boom was added to the economic impulse and consequent urban growth in the southeastern cities of the country, including Villahermosa (Bazant, 2010). In this field, from 1993 to 2007, the forest area decreased from 36 to 9 % in the basin of Grijalva-Usumacinta (Kolb & Galicia 2012). The loss of vegetation and wetland cover in the basin has been linked to city growth, deforestation for livestock use, and logging and oil exploitation (Kolb, Mas, & Galicia, 2013;Perevochtchikova & Lezama, 2010).…”

“…In the period 1984-2008, the rate of land use change of the arboreal vegetation was of -4.63 %, being greater than that recorded in the Grijalva-Usumacinta basin and country. Kolb and Galicia (2012) The analysis of land use change shows that Villahermosa is expanding uncontrollably in the face of poor sustainable development, from being a compact city it transformed into a sectorial perimeter and then into a fragmented city, which is common in Latin American cities (Bähr & Borsdorf, 2005). The city shows a growth pattern associated with industrialization, land use regulations, regional economy, population movements, demand for agricultural products and political environment providing total control to the real estate sector and socio-cultural processes (Kolb et al, 2013Linard, Tatem, & Gilbert, 2013.…”

“…En la década de los años 70, el inicio del boom petrolero se sumó al impulso económico y consecuente crecimiento urbano en las ciudades del sureste del país, entre ellas Villahermosa (Bazant, 2010). En este ámbito, de 1993 a 2007, el área de las selvas disminuyó de 36 a 9 % en la cuenca del Grijalva-Usumacinta (Kolb & Galicia, 2012). La pérdida de la cobertura vegetal y de los humedales en la cuenca se ha relacionado con el crecimiento de la ciudad, la deforestación con fines de uso ganadero y la explotación forestal y petrolera (Kolb, Mas, & Galicia, 2013;Perevochtchikova & Lezama, 2010).…”

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“…En esta región, la periurbanización de Villahermosa produjo la modificación de la fisiografía de su territorio, ya que proliferó la práctica de fragmentar los humedales y rellenar sus áreas de inundación temporal, a lo que se añadió la deforestación y transformación de la red fluvial superficial de los ríos de la cuenca Grijalva (Kolb y Galicia, 2012;Navarro y Toledo, 2008;Zavala y Castillo, 2007;Sánchez et al, 2015). Esta modificación de la red fluvial superficial de la cuenca Grijalva destaca debido a que, sumado su flujo al de la cuenca del río Usumacinta, ambas son la principal reserva de agua de México (Sánchez et al, 2015), y es donde se registra la máxima biodiversidad de peces del país (Miller et al, 2005).…”