RESUMEN
Tropical montane forests (TMF) of the threatened Atlantic Forest hotspot play an important role in providing essential ecosystem services associated with hydrological regime and biodiversity conservation. However, important ecological patterns such as those related to the woody carbon biogeochemical cycle are not yet known for these forests, especially those located at high elevations (> 1500 m. a.s.l.). Herein, we used a dataset of 60 plots (2.4 ha) of old-growth TMF sampled along a high-elevation gradient (1500-2100 m a.s.l.) and monitored in two inventories (2011 and 2016) to better understand the patterns of carbon stock and uptake of these high-elevation forests and the related environmental (soil) and elevation controls. We found differences in the carbon stock along different elevation levels (120.36-170.4C.ton.ha-1) and a carbon accumulation trend over the period along the entire gradient. Thus, forest carbon gain (3.82-5.14 ton.ha.year-1) was greater than the carbon loss (2.1-3.4 ton.ha.year-1) and resulted in a positive productivity net. In other words, the TMF acted as a carbon sink, removing carbon from the atmosphere and storing it in woody tissues. Soil variables also exert significant influences on carbon stock and uptake (significative effects of phosphorus on carbon stock and of cation exchange capacity on carbon loss), driving such patterns in isolation or in interaction with elevation. Considering the high conservation degree of the TMF monitored, our results may be indicative of a similar trend in other similar forests, but which have gone through disturbances in the more recent past. These TMF fragments have a wide occurrence in the Atlantic Forest hotspot and may also be acting or will soon act as carbon sinks in improved conservation scenarios. Thus, these forests can play an essential role in conserving ecosystem services in the region and in mitigating climate changes.
Asunto(s)
Carbono , Ecosistema , Bosques , Madera , Secuestro de Carbono , Suelo , Clima Tropical , Árboles , BiomasaRESUMEN
Brazil has a high diversity of birds and presents the largest number of threatened bird species in the neotropical region. Even so, there are gaps in the bird knowledge, especially in ecotonal montane regions. Given this panorama, this study aimed to analyse the bird community distribution (richness, composition, and beta diversity between phytophysiognomies) of an ecotonal montane landscape of southeastern Brazil, with the purpose of detecting substitution patterns of bird species on a meso-scale. Using bird data performed during the years 1998 to 2015 in 46 sampling points, we found high bird richness in montane phytophysiognomies along an ecotone between Cerrado and Atlantic Forest hotspots. The composition present species of both domains, with high turnover component. We highlight the field environments and candeais are considered homogeneous and threathened, which would directly affect birds. The present study contributes to future conservation strategies, as it demonstrates ecotonal regions as transition zones and reinforces the need to consider as particular ecological units. These ecotonal regions are key locations for understanding ecological patterns in response to environmental changes or phytophysiognomies. Knowing how partitioning of the composition occurs within an environmental mosaic is essential to understand the limits and distributions of the species and conserve them.
Asunto(s)
Animales , Aves , BiodiversidadRESUMEN
Studies about the birds of rupestrian fields in the south of Minas Gerais State in Southeastern Brazil are incomplete, although this region is ornithologically well studied. This bird community has closely associated ecology with fields and the most endangered species of the Cerrado domain. The objective of this manuscript is to create a list of birds which occur in the rupestrian fields of seven municipalities in the south of Minas Gerais State, and further to analyze the birds distribution, the endangered species (and their conservation status), and generate bases for future conservation actions. We evaluated seven cities in the south of Minas Gerais State between 2012 and 2018 by using binoculars and cameras. We found a high richness in relation to other open areas, with the Tyrannidae and Trochilidae families being the most representative. We highlight the endangered species in the Cerrado domain which of these species are closely linked to rupestrian fields. The composition is similar to closer areas, with exception to São Thomé das Letras city because it suffers an influence of mining areas. We suggest creating a wildlife protected area to preserve and conserve a great area of rupestrian fields and consequently the associated biota, especially the bird communities