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1.
Nat Plants ; 6(12): 1400-1407, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33257859

RESUMO

Forests have re-taken centre stage in global conversations about sustainability, climate and biodiversity. Here, we use a horizon scanning approach to identify five large-scale trends that are likely to have substantial medium- and long-term effects on forests and forest livelihoods: forest megadisturbances; changing rural demographics; the rise of the middle-class in low- and middle-income countries; increased availability, access and use of digital technologies; and large-scale infrastructure development. These trends represent human and environmental processes that are exceptionally large in geographical extent and magnitude, and difficult to reverse. They are creating new agricultural and urban frontiers, changing existing rural landscapes and practices, opening spaces for novel conservation priorities and facilitating an unprecedented development of monitoring and evaluation platforms that can be used by local communities, civil society organizations, governments and international donors. Understanding these larger-scale dynamics is key to support not only the critical role of forests in meeting livelihood aspirations locally, but also a range of other sustainability challenges more globally. We argue that a better understanding of these trends and the identification of levers for change requires that the research community not only continue to build on case studies that have dominated research efforts so far, but place a greater emphasis on causality and causal mechanisms, and generate a deeper understanding of how local, national and international geographical scales interact.


Assuntos
Conservação dos Recursos Naturais/estatística & dados numéricos , Conservação dos Recursos Naturais/tendências , Emprego/tendências , Agricultura Florestal/estatística & dados numéricos , Agricultura Florestal/tendências , Florestas , Ocupações/tendências , Adulto , Mudança Climática , Emprego/estatística & dados numéricos , Feminino , Previsões , Humanos , Internacionalidade , Masculino , Pessoa de Meia-Idade , Ocupações/estatística & dados numéricos
3.
Ecol Appl ; 27(6): 1901-1915, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28593704

RESUMO

Tropical second-growth forests could help mitigate climate change, but the degree to which their carbon potential is achieved will depend on exposure to disturbance. Wind disturbance is common in tropical forests, shaping structure, composition, and function, and influencing successional trajectories. However, little is known about the impacts of extreme winds on second-growth forests in fragmented landscapes, though these ecosystems are often located in mosaics of forest, pasture, cropland, and other land cover types. Indirect evidence suggests that fragmentation increases risk of wind damage in tropical forests, but no studies have found such impacts following severe storms. In this study, we ask whether fragmentation and forest type (old vs. second growth) were associated with variation in wind damage after a severe convective storm in a fragmented production landscape in western Amazonia. We applied linear spectral unmixing to Landsat 8 imagery from before and after the storm, and combined it with field observations of damage to map wind effects on forest structure and biomass. We also used Landsat 8 imagery to map land cover with the goals of identifying old- and second-growth forest and characterizing fragmentation. We used these data to assess variation in wind disturbance across 95,596 ha of forest, distributed over 6,110 patches. We find that fragmentation is significantly associated with wind damage, with damage severity higher at forest edges and in edgier, more isolated patches. Damage was also more severe in old-growth than in second-growth forests, but this effect was weaker than that of fragmentation. These results illustrate the importance of considering landscape context in planning tropical forest restoration and natural regeneration projects. Assessments of long-term carbon sequestration potential need to consider spatial variation in disturbance exposure. Where risk of extreme winds is high, minimizing fragmentation and isolation could increase carbon sequestration potential.


Assuntos
Biomassa , Carbono/análise , Fazendas , Florestas , Vento , Conservação dos Recursos Naturais , Peru , Tecnologia de Sensoriamento Remoto
4.
Ecol Appl ; 24(6): 1323-40, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-29160657

RESUMO

Fire is becoming a pervasive driver of environmental change in Amazonia and is expected to intensify, given projected reductions in precipitation and forest cover. Understanding of the influence of post-deforestation land cover change on fires in Amazonia is limited, even though fires in cleared lands constitute a threat for ecosystems, agriculture, and human health. We used MODIS satellite data to map burned areas annually between 2001 and 2010. We then combined these maps with land cover and climate information to understand the influence of land cover change in cleared lands and dry-season severity on fire occurrence and spread in a focus area in the Peruvian Amazon. Fire occurrence, quantified as the probability of burning of individual 232-m spatial resolution MODIS pixels, was modeled as a function of the area of land cover types within each pixel, drought severity, and distance to roads. Fire spread, quantified as the number of pixels burned in 3 × 3 pixel windows around each focal burned pixel, was modeled as a function of land cover configuration and area, dry-season severity, and distance to roads. We found that vegetation regrowth and oil palm expansion are significantly correlated with fire occurrence, but that the magnitude and sign of the correlation depend on drought severity, successional stage of regrowing vegetation, and oil palm age. Burning probability increased with the area of nondegraded pastures, fallow, and young oil palm and decreased with larger extents of degraded pastures, secondary forests, and adult oil palm plantations. Drought severity had the strongest influence on fire occurrence, overriding the effectiveness of secondary forests, but not of adult plantations, to reduce fire occurrence in severely dry years. Overall, irregular and scattered land cover patches reduced fire spread but irregular and dispersed fallows and secondary forests increased fire spread during dry years. Results underscore the importance of land cover management for reducing fire proliferation in this landscape. Incentives for promoting natural regeneration and perennial crops in cleared lands might help to reduce fire risk if those areas are protected against burning in early stages of development and during severely dry years.


Assuntos
Agricultura , Biodiversidade , Secas , Incêndios , Florestas , Teorema de Bayes , Mapeamento Geográfico , Modelos Biológicos , Modelos Estatísticos , Peru
5.
J Parasitol ; 99(6): 1089-98, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24032642

RESUMO

Pigmented hemosporidian parasites that do not exhibit erthyrocytic schizogony, and infect birds, chelonians, and squamates, have been classified in various genera over time. These classifications have reflected vertebrate hosts, insect vectors, and variations in morphology and life history observed in representative species. Side-necked turtles ( Podocnemis spp.) from the Peruvian Amazon were screened for hemoparasites and 2 species of hemosporid parasites infecting these hosts were observed. Molecular phylogenetic analysis of these new isolates, along with parasites from lizards, a snake, and a variety of Haemoproteus species from birds from both the Haemoproteus and Parahaemoproteus subgenera, strongly support the separation of the non-avian parasites into a separate genus. The name with precedent for this group is Haemocystidium Castellani and Willey 1909, and we propose that subgeneric classification of Haemocystidium and Simondia be applied to parasites of squamates and chelonians, respectively. We offer a description of Haemocystidium (Simondia) pacayae n. sp. and a redescription of Haemocystidium (Simondia) peltocephali ( Lainson and Naiff 1998 , n. comb.) Morphologically, the parasites are quite similar, with H. pacayae slightly more elongated than H. peltocephali. The discovery and identification of parasite species is urgent, especially in endangered species and wildlife inhabiting rapidly declining ecosystems such as the Amazon.


Assuntos
Haemosporida/classificação , Infecções Protozoárias em Animais/parasitologia , Tartarugas/parasitologia , Animais , Biodiversidade , Brasil/epidemiologia , DNA de Protozoário/química , DNA de Protozoário/isolamento & purificação , Elapidae/parasitologia , Eritrócitos/parasitologia , Água Doce , Haemosporida/genética , Haemosporida/isolamento & purificação , Peru/epidemiologia , Filogenia , Reação em Cadeia da Polimerase/veterinária , Prevalência , Infecções Protozoárias em Animais/epidemiologia , Análise de Sequência de DNA/veterinária , África do Sul
6.
Mitochondrial DNA ; 23(3): 230-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22651234

RESUMO

We present a mtDNA analysis of Podocnemis expansa (n = 81) and Podocnemis unifilis (n = 228) turtles traded in Peru to evaluate the potential origin of these animals. In particular, we were interested in the relationship between samples reported in the Iquitos markets (IMs) and a Pacaya Samiria Natural Reserve (PSNR) where illegal hunting is presumed. Our mtDNA data showed that, for both species, all haplotypes found within the PSNR were observed in the IM, and that these markets also displayed haplotypes not documented in the reserve. This suggests that the IMs are recipients of Podocnemis turtles from within and outside the PSNR. The fact that most of the haplotype diversity observed in the markets was not found within the PSNR strongly suggests that Podocnemis genetic diversity is exploited in areas where conservation actions are limited. Hence, we recommend expanding Podocnemis conservation efforts outside of protected areas.


Assuntos
Conservação dos Recursos Naturais , DNA Mitocondrial/genética , Genética Populacional , Rios , Tartarugas/genética , Animais , Sequência de Bases , Cidades , Comércio , Frequência do Gene , Marcadores Genéticos , Variação Genética , Haplótipos , Dados de Sequência Molecular , Peru , Análise de Sequência de DNA
7.
Environ Manage ; 43(2): 197-209, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18946698

RESUMO

Fishers and small-scale fisheries worldwide have been marginalized historically. Now it is clear that integrating fishers in management processes is key to resource conservation, but it is less clear how to do it. Here, based on a literature review and new information, we present and analyze a case in which the participation of fishers in the management process was crucial in recovering an overexploited small-scale fishery for the pirarucu (Arapaima spp.) in the Amazon Basin, Brazil. In 8 years of experimental management, from 1999 to 2006, the population of pirarucu increased 9-fold (from about 2200 to 20,650 individuals), harvest quotas increased 10-fold (from 120 to 1249 individuals), and fishers' participation in the management process increased and they benefited from increased monetary returns. Additionally, the number of communities conducting the management scheme increased from 4 in 1999 to 108 in 2006, following the demands of fishers and regional government agencies. Based on our analysis, we suggest that the participation of fishers in the management of other small-scale fisheries in the world can be improved by focusing on (1) applying the knowledge and skills of fishers in resource monitoring and management, (2) bridging knowledge systems among all involved stakeholders, (3) collaborating with fishers that are interested in, and capable of conducting, resource conservation schemes, and (4) conducting management under conditions of uncertainty.


Assuntos
Participação da Comunidade/métodos , Conservação dos Recursos Naturais/métodos , Pesqueiros/métodos , Peixes/crescimento & desenvolvimento , Animais , Brasil , Pesqueiros/economia , Humanos , Dinâmica Populacional , Rios
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