Quantifying patterns of deforestation and linking these patterns to potentially influencing variables is a key component of modelling and projecting land use change. Statistical methods based on null ...hypothesis testing are only partially successful for interpreting deforestation in the context of the processes that have led to their formation. Simplifications of cause-consequence relationships that are difficult to support empirically may influence environment and development policies because they suggest simple solutions to complex problems. Deforestation is a complex process driven by multiple proximate and underlying factors and a range of scales. In this study we use a multivariate statistical analysis to provide contextual explanation for deforestation in the Usumacinta River Basin based on partial pattern matching. Our approach avoided testing trivial null hypotheses of lack of association and investigated the strength and form of the response to drivers. As not all factors involved in deforestation are easily mapped as GIS layers, analytical challenges arise due to lack of a one to one correspondence between mappable attributes and drivers. We avoided testing simple statistical hypotheses such as the detectability of a significant linear relationship between deforestation and proximity to roads or water. We developed a series of informative generalised additive models based on combinations of layers that corresponded to hypotheses regarding processes. The importance of the variables representing accessibility was emphasised by the analysis. We provide evidence that land tenure is a critical factor in shaping the decision to deforest and that direct beam insolation has an effect associated with fire frequency and intensity. The effect of winter insolation was found to have many applied implications for land management. The methodology was useful for interpreting the relative importance of sets of variables representing drivers of deforestation. It was an informative approach, thus allowing the construction of a comprehensive understanding of its causes.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fruit-eating bats play a fundamental role in animal seed dispersal and should be considered key actors in tropical forest restoration. We explored the use of commercial fruits as attractants for bats ...to increase seed dispersal to areas affected by forest fires in southern Mexico. We captured bats and collected seeds from feces and seed rain at perturbed sample sites where mature bananas and mangos were placed, and from non-treated control sites. Bat and bat-dispersed plant species richness and abundance were analyzed, and the importance of each bat species as a disperser was evaluated. Additionally, germination boxes were set up to evaluate the germination of seeds found in bat feces. We captured 724 individuals of 16 frugivorous bat species, 15 spp in treated and 12 spp in control sites. Sowell's Short-tailed bat, Toltec Fruit-eating bat and the Western Long-tongued bat showed higher abundances in treated sites, suggesting that these three species were attracted by fruits. The most important disperser was the Sowell's Short-tailed bat, followed by the Jamaican Fruit-eating and Toltec Fruit-eating bat. A greater proportion of pioneer species and trees, followed by shrubs, were found in the overall bat diet. The germination percentage was > 50%, suggesting that the use of fruits to attract bats can be a feasible wildlife management activity to encourage the succession process. We recommend further studies to test and improve this activity.
Es de gran importancia conocer y evaluar las enfermedades zoonóticas emergentes que existen en el sureste de México, ya que representan una amenaza significativa para la salud pública. Los cambios ...antropogénicos, por ejemplo, la deforestación, el establecimiento de monocultivos, el aumento de la urbanización y la densidad poblacional humana son responsables de la mayoría de las enfermedades infecciosas emergentes zoonóticas. Pronósticos de eventos emergentes indican que en los países con ambientes tropicales (como México) existe una mayor diversidad de zoonosis transmitidas por animales silvestres, por lo que debemos contener y dar rápida respuesta ante posibles brotes de dengue hemorrágico y otras fiebres hemorrágicas virales (FHV). Es importante contar con datos actualizados de las posibles áreas de distribución y ecosistemas de las especies de mamíferos (en particular roedores y murciélagos) que potencialmente pueden ser reservorios o vectores de varias de las FHV, crear modelos con información base para contener brotes de FHV, así como determinar los cambios en los ambientes y la distribución de especies afectadas por actividades humanas.
Anthropized landscapes play a crucial role in biodiversity conservation, as they encompass about 90% of the remaining tropical forest. Effective conservation strategies require a deep understanding ...of how anthropic disturbances determine diversity patterns across these landscapes. Here, we evaluated how attributes and assembly mechanisms of dung beetle communities vary across the Selva El Ocote Biosphere Reserve (REBISO) landscape.
Community attributes (species diversity, abundance, and biomass) were assessed at the landscape scale, using spatial windows and vegetation classes. Windows were categorized as intact, variegated, or fragmented based on their percent cover of tropical forest. The vegetation classes analyzed were tropical forest, second-growth forest, and pastures.
We collected 15,457 individuals and 55 species. Variegated windows, tropical forests, and second-growth forests showed the highest diversity values, while the lowest values were found in intact windows and pastures. Landscape fragmentation was positively and strongly related to dung beetle diversity and negatively related to their abundance; biomass was positively associated with forest cover. Beta diversity was the primary driver of the high dung beetle diversity in the landscape analyzed.
The landscape heterogeneity and its biodiversity-friendly matrix facilitate the complementarity of dung beetle assemblages in the Selva El Ocote Biosphere Reserve. Random processes govern beta diversity patterns in intact and variegated windows. Therefore, vegetation cover in the region is sufficient to maintain a continuous flow of dung beetles between forested landscape segments. However, intense anthropic disturbances acted as deterministic environmental filters in fragmented windows and pastures sites, leading to biotic homogenization processes. Our results suggest that increasing habitat variegation in highly fragmented sites is an effective strategy to prevent or buffer homogenization processes in the REBISO landscape.
Dengue fever, caused by the dengue virus (DENV), is one of the most important reemerging viral diseases transmitted by arthropods worldwide. DENV is maintained in nature in two transmission cycles: ...urban and sylvatic. The latter has only been recorded in Africa and Asia and involves nonhuman primates as natural hosts, although it has been suggested that other mammals may play a secondary role as potential reservoir host, including bats. The objective of this article is to review the current state of knowledge about DENV-positive bats in the Americas and to determine what ecological and human impact variables could favor DENV infection in bats. We performed a search of published studies on natural and experimental DENV infection in bats. From 1952 to 2019, 14 studies have been carried out (71.4% in the last decade) examining DENV infection in bats in seven countries of the Americas. DENV infection was examined in 1884 bats of 63 species and DENV was detected in 19 of these species. Clench's model estimated that more than 75 species could be carriers of DENV; therefore, considering that at least 350 species of bats are distributed in the Americas, to detect 95% of the DENV-bearing species, it would be necessary to examine about 10,206 bats of ∼287 species that have not been analyzed until 2019. The species with the highest number of positive cases were
and
. Species, colony size, mean annual temperature, mean annual precipitation, human population size, and bat collection site (site inhabited by humans, vegetation cover, and caves) contributed to explain the variation in DENV detection in bats in the Americas. These results provide evidence on the exposure of bats to DENV in different geographic areas of the Americas and a bat sylvatic transmission cycle is very likely to be occurring, where bats may be either accidental hosts, dead-end hosts, or potential reservoir hosts for DENV.
There is increasing recognition that ecosystems and their services need to be managed at landscape scale and greater. The development of landscape-scale conservation strategies need to incorporate ...information from multiple sources. In this study, we combine various research tools to link landscape patterns with production units and systems in the Usumacinta River Basin, and inform the discussion of key questions around decision-making related to conservation action and policy in Southern Mexico. A typology based on policy-relevant farmer characteristics (land tenure, farm size, source of income, farming system) differentiated between farmers (traditional vs. cattle ranching) with different motivations that determine how management affects landscape configuration. Five main types of traditional farming systems were identified that combine different forms of land use and vary in their degree of land intensification. Major fragmentation and decrease in connectivity coincided spatially with floodplains dominated by large-scale commercial farms that specialize in livestock production. Traditional practices within large units with low-sloped high quality land were also seen to be intensive; however the presence of trees was notable throughout these units. Policies that promote livestock farming are among the principle causes motivating deforestation. Land intensification by traditional farmers decreased as the landscape became increasingly rugged. Traditional farmers are the focus of initiatives developed by the Biological Corridor project which seeks to increase forest cover and landscape connectivity. These initiatives have shown high levels of rural participation (10,010 farmers benefited from 27,778 projects involving 95,374 ha of land) and acceptance (producers carried out more than one project and several types of projects during the first eight years of work). Strong action is still required to take on the segment of large-scale ranchers. Changes in the structure of land tenure over the past decade are highlighted that could have a profound impact on conservation policies and programs.
•Key to address conservation options is the heterogeneity of farming systems.•Conservation programs receive high degree of acceptance from traditional farmers.•Strong action is still required to take on the segment of large-scale ranchers.•Well-managed areas tend to increase more with moderate and sustained financial support.•Recent changes in the structure of land tenure threatens conservation programs.
Human decisions and modes of organization can be analyzed according to their rationale, which can be based on hierarchies, markets, or networks. This classification is known as governance modes. This ...article addresses municipal solid waste (MSW) governance inside and outside protected areas based on the Sepultura Biosphere Reserve (REBISE) case in Chiapas, Mexico. We conducted semi-structured interviews and a content analysis of laws and municipal regulations to identify the stakeholders and institutions that operate at community and municipal levels. Our research is a first effort to analyze the modes of MSW governance and offers a spatially explicit classification to reveal the spatial differences in how MSW is governed. The populations close to the capital city and the main roads have a multiplicity of mechanisms and modes of MSW governance, which contrasts with distant communities located within the REBISE. This work illustrates the gaps where municipal authorities are unable to fulfill their obligations and the potential of market and collaborative mechanisms. Characterizing governance modes through spatially explicit thematic maps reveals the interactions between stakeholders and formal and informal institutions, which could contribute to territorial planning toward more effective MSW governance.
Urban gardens are a prominent part of agricultural systems, providing food security and access within cities; however, we still lack sufficient knowledge and general principles about how to manage ...pests in urban agroecosystems in distinct regions. We surveyed natural enemies (ladybeetles and parasitoids) and conducted sentinel pest removal experiments to explore local management factors and landscape characteristics that influence the provisioning of pest control services in California, USA, and Chiapas, Mexico. We worked in 29 gardens across the two locations. In each location, we collected data on garden vegetation, floral availability, ground cover management, and the percentage of natural, urban, and agricultural land cover in the surrounding landscape. We sampled ladybeetles, Chalcidoidea, and Ichneumonoidea parasitoids with sticky traps, and monitored the removal of three different pest species. Ladybeetle abundance did not differ between locations; abundance decreased with garden size and with tree cover and increased with herbaceous richness, floral abundance, and barren land cover. Chalcicoidea and Ichneumonoidea parasitoids were more abundant in Chiapas. Chalcicoidea abundance decreased with herbaceous richness and with urban cover. Ichneumonoidea abundance increased with mulch and bare ground cover, garden size, garden age, and with agriculture land cover but decreased with tree richness and urban cover. Predators removed between 15–100% of sentinel prey within 24 h but prey removal was greater in California. Generally, prey removal increased with vegetation diversity, floral abundance, mulch cover, and urban land cover, but declined with vegetation cover and bare ground. Although some factors had consistent effects on natural enemies and pest control in the two locations, many did not; thus, we still need more comparative work to further develop our understanding of general principles governing conservation biological control in urban settings.
Mayan community forest reserves (MCFR) play an important role in agricultural landscapes in Mexico, as they provide forest products and a broad variety of benefits that contribute to improving local ...people's livelihoods. Nevertheless, academia has generally considered conservation and use of forest resources to be incompatible. We describe the spatial configuration of MCFR, evaluate floristic and structural characteristics of woody vegetation present in selected reserves, and identify social norms that govern use and conservation of MCFR. These reserves largely consist of mature vegetation (80% of total cover); their plant structure is similar to that of the surrounding tropical sub-deciduous forest; and they house a large number of endemic species. The MCFR studied contain a total of 146 tree species and cover 11% of the study area, which includes at least 140 villages in the north-central part of the Yucatan Peninsula. These reserves are collectively managed and conserved by Mayan peasants in the interest of the common good. The communities in our study area combine conservation and use of forest resources, and we recommend that in public policy, government agencies and NGOs incorporate MCFR as a model of biological conservation and sustainable natural resource use, taking into account traditional knowledge and local norms that allow these reserves to function in a sustainable manner.
•Mayan people manage local forest reserves under the principle of the common good.•Forest reserves sustain high number of species richness respecting mature forests.•They provide forest products, as well as a broad variety of environmental services.•Community forest reserves constitute network of biological connectivity.•Community forest reserves represent a model of biological conservation and sustainable use.
Knowledge, perceptions, and attitudes toward raptors were assessed from July to December 2019 through exploratory research conducted online (n = 278) and in-depth interviews (n = 18) with ...participants having knowledge of information technologies in urban areas of the Riviera Maya, Quintana Roo, Mexico. Most respondents were young (ages 13-37), permanent residents of the cities of Cancun, Playa del Carmen, Puerto Morelos, and Tulum. We found heterogeneous attitudes toward raptors, including "scientific," "environmentalist-conservationist," "aesthetic," "dominant," and "utilitarian." Our results suggest that most participants had a relatively high level of knowledge, positive perceptions, and environmentalist-conservationist attitudes toward raptors, probably due to the nature of the convenient sampling applied. We recommend further studies on human-raptor relations in urban and rural localities of coastal Quintana Roo, including residents of Mayan origins. This information may help support strategies and programs to reduce negative perceptions and indifference toward raptors and might support their conservation in the Mexican Riviera Maya.
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