No abstract

Plant distributions result from a variety of biophysical conditions and, often, human activities. Distributions change depending on numerous factors, such as climate change or the presence of seed dispersal agents. The present distribution of the jícaro (Crescentia alata and Crescentia cujete) or calabash tree in Central America may be the result of several factors, key among them direct human management. Many savanna pastures in Central America have been invaded in recent decades by woody vegetation, mostly as a result of fire suppression and fencing. However, observations reveal that its presence is not merely due to invasion. Humans manage the tree, protecting and encouraging its presence in semi-arid cattle producing landscapes where it serves as food for cattle when the dry season drastically reduces herbaceous forage. This adaptive strategy addresses issues of agroforestry and biodiversity, biomass and carbon sequestration, and the domestication process in which we humans have so long been engaged. ResumenLas distribuciones de las plantas resultan de una variedad de condiciones biofísicas y, en muchos casos, de las actividades humanas que cambian en relación con numerosos factores como el clima, o la presencia de agentes que esparcen las semillas. La actual distribución del jícaro (Crescentia alata y Crescientia cujete o calabaza) en América Central puede ser el resultado de varios factores, clave entre ellos, el manejo directo del hombre. Las observaciones revelan que su presencia no es solamente causada por invasión, sino que cómo el hombre está manejando el árbol, protegiéndolo y apoyando su presencia en un paisaje semi-árido de ganadería, donde sirve como insumo para el ganado cuando la estación seca reduce el forraje. Esta estrategia de adaptación la confrontan los asuntos de silvicultura y biodiversidad, el biomasa y la captura del carbón y también el proceso de domesticación en el cual el hombre ha estado envuelto a largo plazo.

Repeat photography is the process of rephotographing the same scene that appears in an earlier photograph. As a methodology, repeat photography is a valuable tool for investigating and assessing landscape change. Beyond the disadvantages of scale, composition, areal coverage and temporal punctuation, the method is useful. Photographs are comprehensive views that offer a 'contextualized' landscape to examine. As well, the unexpected may be revealed through the process. My research in Honduras using this method led me to find a vegetation increase, rather than the decrease that was expected of a tropical area. A few example photographs illustrate the variety of manifestations this increase takes.

Geographers interested in vegetation change increasingly focus on forest transitions. Several studies have documented an increase in forest cover in tropical America. This paper examines the nature of land cover change between 1954 and 1992 in a mountainous region of western Honduras. Analysis of aerial photographs indicates that tree cover increased by 17% around the town of Marcala. The accuracy of the aerial photograph analysis was assessed by field reconnaissance in 2004, which suggested that the increase in trees consisted largely of shade coffee fincas. More than 80% of the 46 field sites visited in this study experienced an increase in tree cover, which consisted of pine forest and several types of shaded tree canopies for the growth of coffee.

No abstract