Modelamiento biogeográfico de especies forestales maderables nativas para la recuperación de bosques degradados en Amazonas, Perú

La pérdida de cobertura boscosa y la reducción de poblaciones de especies maderables es un problema ambiental que afecta de manera importante el territorio del departamento de Amazonas, Perú. El presente estudio analiza modelos de distribución potencial de diez (10) especies forestales maderables con mayor aprovechamiento en Amazonas, a partir de permisos forestales maderables otttorgados en Amazonas, desde el año 2016 al 2019. Posteriormente, se establecieron las áreas de distribución potencial de las especies forestales maderables: Apuleia leiocarpa “anacaspi”, Calycophyllum spruceanum “capirona”, Cariniana decandra “papelillo” o “cachimbo”, Cedrela montana “cedro”, Cedrela odorata “cedro amargo”, Cedrelinga cateniformis “tornillo”, Ceiba pentandra “lupuna”, Hura crepitans “catahua”, Inga sp. “guabilla” y Otoba parvifolia “sempo”, mediante un modelamiento de máxima entropía – MaxEnt. Para esto, se utilizaron 19 variables bioclimáticas, 3 topográficas, 3 edáficas, y la radiación solar, con una resolución espacial de 250 metros. Estas variables permitieron elaborar mapas de distribución en base a patrones similares de probabilidad de presencia para las especies en estudio. Un total de 37,686.17 m3 de madera rollliza (r), fueron otorgados para aprovechamiento maderable en Comunidades Nativas, Comunidades Campesinas y Predios Privados. Se estimó que la distribución potencial de 9 de las especies evaluadas corresponde a las provincias de Bagua y Condorcanqui. La especie Cedrela montana se distribuiría en las provincias de Rodríguez de Mendoza y Bongará, encontrándose además con mayor distribución dentro del Sistema de Conservación Regional de Amazonas. El presente estudio contribuye como herramienta para procesos de conservación y recuperación en bosques degradados del departamento de Amazonas.Tesi

Predicting potential distribution and identifying priority areas for conservation of the Yellow-tailed Woolly Monkey (Lagothrix flavicauda) in Peru

Species distribution models (SDMs) provide conservationist with spatial distributions estimations of priority species. Lagothrix flavicauda (Humboldt, 1812), commonly known as the Yellow-tailed Woolly Monkey, is one of the largest primates in the New World. This species is endemic to the montane forests of northern Peru, in the departments of Amazonas, San Martín, Huánuco, Junín, La Libertad, and Loreto at elevation from1,000 to 2,800 m. It is classified as “Critically Endangered” (CR) by the International Union for Conservation of Nature (IUCN) as well as by Peruvian legislation. Furthermore, it is listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Research on precise estimates of its potential distribution are scare. Therefore, in this study we modeled the potential distribution area of this species in Peru, the model was generated using the MaxEnt algorithm, along with 80 georeferenced occurrence records and 28 environmental variables. The total distribution (high, moderate, and low) for L. flavicauda is 29,383.3 km2, having 3,480.7 km2 as high potential distribution. In effect, 22.64 % (6,648.49 km2) of the total distribution area of L. flavicauda is found within Natural Protected Areas (NPAs), with the following categories representing the largest areas of distribution: Protected Forests (1,620.41 km2), Regional Conservation Areas (1,976.79 km2), and Private Conservation Areas (1,166.55 km2). After comparing the predicted distribution with the current NPAs system, we identified new priority areas for the conservation of the species. We, therefore, believe that this study will contribute significantly to the conservation of L. flavicauda in Peru

Rediscovering the Richness and Endemism of the Tetrapod Fauna within the Utcubamba River Key Area for Biodiversity, in Northwestern Peru

The tropical Andes in South America stand at the top of the world’s list of endemism hotspots, due to their high species richness per unit area. Thus, our study focuses on the Key Biodiversity Area (KBA) of the Utcubamba River (PER-84), one of the 96 KBAs, with an extension of 35,534 hectares. This area is located in northwest Peru, within the hotspot of the tropical Andes. The study area is well known as the waterfalls valley, which holds the world’s third highest waterfall “Gocta”, an outstanding national and international tourist attraction. Nevertheless, despite its great ecological and tourist value, research reports are deficient in the area. Therefore, we conducted a biological inventory in 2019 during the wet season, with the aim of recording and identifying species of tetrapod fauna, as well as promoting actions for their conservation. Based on field assessments, the following number of species was recorded: amphibians (14), reptiles (6), birds (229), and mammals (20). Interestingly, for the first time, two species of amphibians (Gastrotheca aguaruna and Gastrotheca spectabilis) and two reptiles (Dipsas palmeri and Tachymenis affinis) have been recorded; furthermore, the following several endemic species have been observed: amphibians (3), reptiles (2), birds (3) and mammals (1) that have not yet been reported for the ACB, which have not yet been reported for the KBA. This finding, in fact, increases the number of species of endemism in this part of Peruvian territory. Consequently, this study aims to be the basis for promoting further research to discover new species for science and to propose strategies for their conservation over time

Land Suitability for Cocoa Cultivation in Peru: AHP and MaxEnt Modeling in a GIS Environment

Peru is one of the world’s leading exporters of cocoa beans, which directly impacts the household economy of millions of small farmers. Currently, the expansion and modernization of the cocoa-growing area require the zoning of the territory with suitable biophysical and infrastructural conditions to facilitate optimizing productivity factors. Therefore, we analyzed land suitability for cocoa (Theobroma cacao L.) production on the Peruvian mainland as a support measure for sustainable agriculture. To this end, the climatological, edaphological, orographic, and socioeconomic criteria determining sustainable cocoa cultivation were identified and mapped. Three modeling approaches (Analytic Hierarchy Process—AHP, Maximum Entropy—MaxEnt, and AHP—MaxEnt combined) were further used to hierarchize the importance of the criteria and to model the potential territory for sustainable cocoa cultivation. In all three modeling approaches, climatological criteria stood out among the five most important criteria. Elevation (orographic criteria) is also featured in this group. On the other hand, San Martin and Amazonas emerged as the five regions with the largest area ‘Highly suitable’ for cocoa cultivation in all three modeling approaches, followed by Loreto, Ucayali, Madre de Dios, Cusco, Junín, and Puno, which alternated according to modeling approach. From most to least restrictive, the AHP, MaxEnt, and AHP–MaxEnt modeling approaches indicate that 1.5%, 5.3%, and 23.0% of the Peruvian territory is ‘Highly suitable’ for cocoa cultivation, respectively

The Challenge of Wildlife Conservation from Its Biogeographical Distribution Perspectives, with Implications for Integrated Management in Peru

Biodiversity is an indispensable resource and contributes to the balance of ecosystems, being of great importance for the development of a society and its culture through good management of natural spaces. However, the reduction in and fragmentation of habitats, trafficking, and illegal trade in wild animals affect the great diversity of wild flora and fauna that characterize Peru. Considering this problem, we modeled the biogeographic distribution of five species of wildlife categorized as threatened by Peruvian legislation and included in the red list of threatened species of the International Union for the Conservation of Nature (IUCN): critically endangered (CR) Lagothrix flavicauda, endangered (EN) Aotus miconax, in vulnerable-status (VU) Tremarctos ornatus and Lagothrix cana, and in the near-threatened category (NT) Panthera onca. Our study aimed to identify their current potential distribution in the Peruvian territory which is legally protected by the conservation areas of national, regional, or private administration. In this regard, we used a maximum-entropy approach (MaxEnt), integrating 14 variables (7 bioclimatic variables, 3 topographic, 3 variables of vegetation cover, and relative humidity). It was observed that 3.6% (46,225.50 km2) of the Peruvian territory presented a high probability (>0.6) of distribution of the evaluated species and 10.7% (136,918.28 km2) of moderate distribution (0.4–0.6). Based on this, our study allowed us to identify the geographical spaces for threatened species on which conservation actions should focus, through the formulation of strategies, plans, policies, and participatory management in the Peruvian territory

Biogeographic Distribution of Cedrela spp. Genus in Peru Using MaxEnt Modeling: A Conservation and Restoration Approach

The increasing demand for tropical timber from natural forests has reduced the population sizes of native species such as Cedrela spp. because of their high economic value. To prevent the decline of population sizes of the species, all Cedrela species have been incorporated into Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The study presents information about the modeled distribution of the genus Cedrela in Peru that aims to identify potential habitat distribution of the genus, its availability in areas protected by national service of protected areas, and highlighted some areas because of their conservation relevance and the potential need for restoration. We modeled the distribution of the genus Cedrela in Peru using 947 occurrence records that included 10 species (C. odorata, C. montana, C. fissilis, C. longipetiolulata, C. angustifolia, C. nebulosa, C. kuelapensis, C. saltensis, C. weberbaueri, and C. molinensis). We aim to identify areas environmentally suitable for the occurrence of Cedrela that are legally protected by the National Service of Protected Areas (PAs) and those that are ideal for research and restoration projects. We used various environmental variables (19 bioclimatic variables, 3 topographic factors, 9 edaphic factors, solar radiation, and relative humidity) and the maximum entropy model (MaxEnt) to predict the probability of occurrence. We observed that 6.7% (86,916.2 km2) of Peru presents a high distribution probability of occurrence of Cedrela, distributed in 17 departments, with 4.4% (10,171.03 km2) of the area protected by PAs mainly under the category of protection forests. Another 11.65% (21,345.16 km2) of distribution covers areas highly prone to degradation, distributed mainly in the departments Ucayali, Loreto, and Madre de Dios, and needs immediate attention for its protection and restoration. We believe that the study will contribute significantly to conserve Cedrela and other endangered species, as well as to promote the sustainable use and management of timber species as a whole

Potential Current and Future Distribution of the Long-Whiskered Owlet (Xenoglaux loweryi) in Amazonas and San Martin, NW Peru

The IUCN has listed the long-whiskered owlet (Xenoglaux loweryi) as vulnerable due to the presence of few geographic records, its restricted range, and anthropogenic threats. Its natural history and ecology are largely unknown, and its distribution is widely debated; therefore, there is an urgent need for the real-time conservation of X. loweryi. In this study, 66 geo-referenced records of X. loweryi, 18 environmental variables, and the maximum entropy model (MaxEnt) have been used to predict the current and future (2050 and 2070) potential distribution of X. loweryi in the Amazonas and San Martin regions of northwestern Peru. In fact, under current conditions, areas of “high”, “moderate”, and “low” potential habitat suitability cover 0.16% (140.85 km2), 0.46% (416.88 km2), and 1.16% (1048.79 km2) of the study area, respectively. Moreover, under future conditions, the “high”, “moderate”, and “low” probability areas present profits and losses in terms of habitat suitability. Based on the environmental variables, this species mostly inhabits areas with a forest fraction with presence of trees with an emergent tree canopy of ~10–30 metres and depends on Yunga montane forest habitats with high humidity but it is not dependent on bare cover area, crops, or grasslands. Nevertheless, most of the current and future distribution areas are not part of the protected natural areas of Amazonas and San Martin. Additionally, the combination of climate change and anthropogenic activities contribute to further losses of this species habitat. Therefore, from the management point of view, corrective and preventive actions will help to preserve this species over time

Distinct purinergic signaling pathways in prepubescent mouse spermatogonia

Spermatogenesis ranks among the most complex, yet least understood, developmental processes. The physiological principles that control male germ cell development in mammals are notoriously difficult to unravel, given the intricate anatomy and complex endo- and paracrinology of the testis. Accordingly, we lack a conceptual understanding of the basic signaling mechanisms within the testis, which control the seminiferous epithelial cycle and thus govern spermatogenesis. Here, we address paracrine signal transduction in undifferentiated male germ cells from an electrophysiological perspective. We identify distinct purinergic signaling pathways in prepubescent mouse spermatogonia, both in vitro and in situ. ATP—a dynamic, widespread, and evolutionary conserved mediator of cell to cell communication in various developmental contexts—activates at least two different spermatogonial purinoceptor isoforms. Both receptors operate within nonoverlapping stimulus concentration ranges, display distinct response kinetics and, in the juvenile seminiferous cord, are uniquely expressed in spermatogonia. We further find that spermatogonia express Ca2+-activated large-conductance K+ channels that appear to function as a safeguard against prolonged ATP-dependent depolarization. Quantitative purine measurements additionally suggest testicular ATP-induced ATP release, a mechanism that could increase the paracrine radius of initially localized signaling events. Moreover, we establish a novel seminiferous tubule slice preparation that allows targeted electrophysiological recordings from identified testicular cell types in an intact epithelial environment. This unique approach not only confirms our in vitro findings, but also supports the notion of purinergic signaling during the early stages of spermatogenesis