Search

The order Odonata has been regularly used as an indicator of the ecosystem's condition. The objective of this review was to analyze the importance of Odonata for environmental assessments (assessment types, statistical approach, life stages, and sampling method, or particular metric), summarizing the current state, the trends, and identifying related research issues in the Neotropical region. Therefore, we selected 62 articles from 2007 to 2018 based on published research to monitor Odonata assessments in the Neotropical region. We compiled a database and ran statistical analyses for the observed frequencies. We found that ecosystem health was the most frequent assessment type and quality the most used objective. In the case of statistical tests and metrics, multivariate analyses and species richness were most used in these papers. However, because there is a great diversity of habitats in this region, there is no unique monitoring protocol to assess the quality of ecosystem health and it is needed to create a proposal for a standard evaluation protocol. Consequently, guidelines for monitoring are presented, and we suggest three stages to establish a specific protocol for each site, which records the set of species most sensitive to the exchange rate evaluated, as well as the use of rarefaction methods, the index of diversity based on the area under the curve, and multivariate analysis, among other recommendations.

Studies have documented biodiversity losses due to intensification of coffee management (reduc- tion in canopy richness and complexity). Nevertheless, questions remain regarding relative sensitivity of different taxa, habitat specialists, and functional groups, and whether implications for biodiversity conserva- tion vary across regions. We quantitatively reviewed data from ant, bird, and tree biodiversity studies in coffee agroecosystems to address the following questions: Does species richness decline with intensification or with individual vegetation characteristics? Are there significant losses of species richness in coffee-management systems compared with forests? Is species loss greater for forest species or for particular functional groups? and Are ants or birds more strongly affected by intensification? Across studies, ant and bird richness declined with management intensification and with changes in vegetation. Species richness of all ants and birds and of forest ant and bird species was lower in most coffee agroecosystems than in forests, but rustic coffee (grown under native forest canopies) had equal or greater ant and bird richness than nearby forests. Sun coffee (grown without canopy trees) sustained the highest species losses, and species loss of forest ant, bird, and tree species increased with management intensity. Losses of ant and bird species were similar, although losses of forest ants were more drastic in rustic coffee. Richness of migratory birds and of birds that forage across vegetation strata was less affected by intensification than richness of resident, canopy, and understory bird species. Rustic farms protected more species than other coffee systems, and loss of species depended greatly on habitat specialization and functional traits. We recommend that forest be protected, rustic coffee be pro- moted, and intensive coffee farms be restored by augmenting native tree density and richness and allowing growth of epiphytes. We also recommend that future research focus on potential trade-offs between biodiversity conservation and farmer livelihoods stemming from coffee production.

In 1998, storms related to Hurricane Isis caused extensive gaps in the cloud forest of El Triunfo Biosphere Reserve in Chiapas, Mexico, where severe storms are infrequent. We examined how this disturbance affected bird species composition. Species richness and composition were similar both between pre- and post-disturbance forest and between newly created gaps and plots that remained forested after the hurricane. However, differences in response guilds were greater between pre- and post-disturbance plots than between forest plots with gaps after disturbance. Granivorous, omnivorous, and terrestrial species were more abundant before the hurricane, whereas insectivorous, midstory, and generalist foragers were more abundant after the hurricane. In addition, species with high sensitivity to disturbance were more abundant in the pre-disturbance forest, while low sensitivity species were more abundant after disturbance. In the post-disturbance forest, insectivorous species were most abundant in gaps and terrestrial-canopy foragers were most abundant in forest plots. Permanently open areas had significantly lower species richness, but had lowland generalist and second-growth species not present in the cloud forest. Results suggest that changes in species composition were not limited to the newly created gaps, but also affected the whole forest. The decline of high sensitivity species after disturbance supports the hypothesis that disturbance negatively affects specialists and benefits generalist species. Although there is evidence that natural communities tend to return to pre-disturbance conditions, changes in community structure could be aggravated if recurrent hurricanes occur before succession takes place.

It has been documented that certain types of shade coffee plantations have both biodiversity levels similar to natural forest and high concentrations of wintering migratory bird species. These findings have triggered a campaign to promote shade coffee as a means of protecting Neotropical migratory birds. Bird censuses conducted in the El Triunfo Biosphere reserve in southern Mexico have confirmed that shade coffee plantations may have bird diversity levels similar to, or higher than, natural forest. However, coffee and forest differed in species composition. Species with a high sensitivity to disturbance were significantly more diverse and abundant in primary ecosystems. Neotropical migratory birds, granivorous and omnivorous species were more abundant in disturbed habitats. Insectivorous bird species were less abundant only in shaded monoculture. Foraging generalists and species that prefer the upper foraging stratum were more abundant in disturbed habitats, while a decline in low and middle strata foragers was found there. Findings suggests that shade coffee may be beneficial for generalist species (including several migratory species), but poor for forest specialists. Although shade coffee plantations may play an important role in maintaining local biodiversity, and as buffer areas for forest patches, promotion of shade coffee may lead to the transformation of forest into shade coffee, with the consequent loss of forest species.

El presente estudio tuvo como finalidad conocer el aprovechamiento de los recursos maderables tropicales nativos por parte de la comunidad Emilio Rabasa, ubicada en la Reserva de la Biosfera Selva El Ocote, en el estado de Chiapas, México. Se realizaron encuestas semiestructuradas a 30 ejidatarios y se colectaron ejemplares para la identificación de las especies. Se determinó un total de 35 especies maderables nativas, incluidas en 31 géneros y 24 familias. Las principales especies maderables multipropósito mencionadas fueron el bojón (Cordia alliodora (R. & P.) Oken), el palo amarillo (Terminalia obovata (R. & P.) Steud) la caoba (Swietenia macrophylla G. King), el jolocín (Heliocarpus donnell-smithii Rose), el cedro (Cedrela odorata M. Roem. King) y el copalchi (Croton guatemalensis Lotsy). Entre los principales usos que la comunidad le da a las especies maderables está, 38% la extracción de leña y postes para cercado, 17% para la elaboración de herramientas de trabajo y 16% para la elaboración de muebles, construcción y reparación de casas.

Southern Mexico is well known for its high biodiversity (CONABIO, 2008). This biodiversity is a result of several factors like its geographic position, geographic diversity, and physiographic richness (Ferrusquilla-Villafranca, 1998). In particular, Chiapas, Mexico's southernmost state holds seven physiographic zones, including valleys, mountain chains, plateaus, and coastal plains (Mullerried, 1957). Most of this biological richness is to be found in the eastern moist forest, northern mountains, central plateau, and Sierra Madre (Breedlove, 1981). The Sierra Madre mountain chain harbors some of the very last patches of Cloud Forest, which is one of the most endangered ecosystems both in Mexico and at a global scale (Challenger, 1998; Toledo-Aceves et al., 2010). Fortunately, three existing biosphere reserves namely El Triunfo, La Sepultura and Volcan Tacana, aim to protect and maintain this highly threatened ecosystem. As elsewhere, natural areas compete for land with human activities such as agriculture and cattle ranching, recently, climate change has added up to the list of threats. Only at El Triunfo reserve between 1983 and 1993 were lost 8,946 ha, including 5,084 ha of Cloud Forest (March & Flamenco, 1996). As a region, the Sierra Madre de Chiapas, was between 1998 and 2005, the region that suffered the greatest impact related to climate change in the form of massive landslides. For example, more than 15,000 ha of Cloud Forest were affected in Chiapas by Hurricane Isis (Richter, 2000), while this phenomenon has also occurred in other parts of the Americas (Restrepo & Alvarez, 2006). The loss of forest cover in the upper parts of the mountain chain generates a reduction of water retention and filtering capability which results in soil loss and consequently in river sedimentation. This also has occasioned an increment of water flow volume which augments flood risk. One way to help to reduce flood risk is through the ecological restoration of forest systems in the upper basin, and subsequent recovery of the ecological services associated to forest. Hence, information on the structure of natural plant communities, including structure and floristic composition, is central to establish sound ecological restoration strategies and policies. Our research objective, was thus, to evaluate and analyze the natural successional process in a cloud forest along a successional gradient

Over the past decade, various strategies have emerged to address critical habitat losses through agricultural expansion. The promotion of shade-grown, premium-priced coffee has been highlighted as one alternative. Our research, based on interviews with farmers in Chiapas, disputes some of the assumptions made by shade coffee campaigners. Results revealed a predisposition to converting forest to shade coffee production due to the socioeconomic challenges farmers face and the potential for increasing incomes. To ensure that their well-being is improved at the same time as reducing environmental impacts, there is clearly a need to provide more detailed information on who is responsible for enforcing certification criteria and how this should take place.

San Cristóbal de Las Casas, Chiapas, México : El Colegio de la Frontera Sur, 2013.