scholarly journals Tree mortality, recruitment and growth in a bamboo dominated forest fragment in southwestern Amazonia, Brazil

2013 ◽  
Vol 13 (2) ◽  
pp. 29-34 ◽  
Author(s):  
Herison Medeiros ◽  
Wendeson Castro ◽  
Cleber Ibraim Salimon ◽  
Izaias Brasil da Silva ◽  
Marcos Silveira

Forest fragmentation affects the structure and dynamics of plant communities, leading to biodiversity loss in forest remnants. In this paper we show that in a bamboo (Guadua weberbaueri Pilger) dominated forest fragment in southwestern Amazonia edge effect may be confounded by bamboo effect, which also occur inside the forest. We measured growth, mortality and, recruitment rate of trees with DBH ≥ 10 cm, in a fragment of bamboo dominated open forest in southwestern Amazonia, state of Acre, Brazil, in 15 plots at the forest edge and 15 plots inside the forest fragment, 500 m away from the border. Time interval between censuses was 1.8 years. The average diameter growth rate differed significantly between edge (3.82 ± 0.10 mm a-1) and interior (2.39 ± 0.18 mm a-1); but there were no differences in annual mortality rate (edge = 3.8 ± 2.5 % a-1 CV = 65.7%; interior = 3.6 ± 2.6% a-1 CV = 72.2%) or in annual recruitment rate (edge = 7.1 ± 3.2% a-1 CV = 45%; interior = 8.9 ± 7.9% a-1 CV = 88.7%). Diameter growth rate, particularly of pioneer and fast-growing trees, is favored by the environmental conditions of the edge, where bamboo abundance is higher. However, the absence of an edge effect on mortality and recruitment could be due to the particular dynamics of bamboo patches, which could be mimicking forest edges and therefore masking possible edge effect in this fragment. We speculate that the mortality and recruitment patterns in fragmented forests of southwestern Amazonia is different from other areas in Amazonia and that bamboo is one of the key controllers of successional processes in these fragments.

2021 ◽  
Vol 28 (3) ◽  
pp. e18793
Author(s):  
Jônatas Lima ◽  
Railene Almeida ◽  
Edson Guilherme

We present new aspects of breeding biology of Gray-fronted Dove Leptotila rufaxilla, from five nests found between 2012 and 2014 in a lowland forest fragment in southwestern Brazil. The nests simple/platform shape were built at a mean height of 1.90 m above ground. The clutch size was two eggs white and elliptic, incubated for 15 days (based on three nests). We recorded predation in two nests still in incubation phase. Minimum hatch weight of nestlings was 10 g and young fledged with a mean mass of 56 g. The constant growth rate (K) of nestlings was 0.40 with a growth asymptote of 60.7 g. Daily survival rate, Mayfield and apparent nesting success in the incubation period was 90, 20 and 56%, respectively, while in the nestling period were all 100%. Our data and the contribution of citizen science showed that L. rufaxilla breeds over the year, mainly in the rainy season, both in southwestern Amazonia and in other regions of occurrence.


2015 ◽  
Vol 45 (7) ◽  
pp. 920-928 ◽  
Author(s):  
Adrian J. Das ◽  
Nathan L. Stephenson

Tree growth rate is frequently used to estimate mortality probability. Yet, growth metrics can vary in form, and the justification for using one over another is rarely clear. We tested whether a growth index (GI) that scales the realized diameter growth rate against the potential diameter growth rate (PDGR) would give better estimates of mortality probability than other measures. We also tested whether PDGR, being a function of tree size, might better correlate with the baseline mortality probability than direct measurements of size such as diameter or basal area. Using a long-term dataset from the Sierra Nevada, California, U.S.A., as well as existing species-specific estimates of PDGR, we developed growth–mortality models for four common species. For three of the four species, models that included GI, PDGR, or a combination of GI and PDGR were substantially better than models without them. For the fourth species, the models including GI and PDGR performed roughly as well as a model that included only the diameter growth rate. Our results suggest that using PDGR can improve our ability to estimate tree survival probability. However, in the absence of PDGR estimates, the diameter growth rate was the best empirical predictor of mortality, in contrast to assumptions often made in the literature.


2021 ◽  
Vol 28 (3) ◽  
pp. e20476
Author(s):  
Jônatas Lima ◽  
Edson Guilherme

We reported the first data on the breeding and growth in Dendroplex picus peruvianus from a forest fragment in southwestern Amazonia. We observed and netted this species between 1999 and 2019. We found two active nests in 2012 and 2013, but we monitored only one. Clutch size was two eggs, incubated for 16 days. The constant growth rate (K) of nestlings was 0.31 with a growth asymptote of 46.3 g. We recorded a longest minimum longevity of eight years. Our records showed that D. p. peruvianus breeds mainly in the rainy season (September–March) overlapping with the molt period.


1993 ◽  
Vol 8 (11) ◽  
pp. 2858-2869 ◽  
Author(s):  
R.A. Bauer ◽  
N.M. Sbrockey ◽  
W.E. Brower

Diamond crystallites and continuous films were deposited on (100) silicon with various surface treatments by microwave plasma assisted CVD at times varying from 2 min to 1600 min. In each experiment, the average diameter of the crystallites increased linearly with time, while the density of crystallites was essentially constant. Thus, nucleation of the diamond occurred within a short time interval early in the deposition process. After the nucleation event, only growth occurred. Various surface treatments were used: untreated, polished with 1 μm diamond, scratched with 350 mesh SiC, scratched with 1 μm alumina, wiped with 350 mesh graphite powder, and spin coated with polymethyl methacrylate. Only the diamond polishing affected the crystallite density, and none of the surface treatments had any effect on crystallite morphology or growth rate. Growth rates were determined by least squares fits to average diameter versus time for crystals and average thickness versus time for films. The growth rate data extrapolate to zero size at zero deposition time. Applying the Volmer–Weber model, an activation energy for nucleation of diamond on silicon was calculated to be 52 kcal/mole.


2016 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Poliana Gabriella Araújo Mendes ◽  
Maria Amanda Menezes Silva ◽  
Tassiane Novacosque Feitosa Guerra ◽  
Ana Carolina Borges Lins-e-Silva ◽  
Airton de Deus Cysneiros Cavalcanti ◽  
...  

ABSTRACT The woody plants in an edge area formed approximately 35 years ago in an Atlantic Forest fragment in northeastern Brazil were examined, and three environments defined: edge, intermediate, and interior. Canopy tree densities and basal areas were found to be similar in all three environments, and also similar to previous published studies in the same region; species richness was greatest at the forest edge. The understory showed greater species richness in the forest interior, but greater diversity and equitability in the intermediate environment. Understory environments close to the forest edge demonstrated larger stem diameters than in the forest interior, although at lesser densities and with smaller total basal areas. Our results indicated the existence of distinct patterns in canopy and understory that most likely reflect differences in the response times of these two vegetation layers, with the understory being more sensitive to alterations in environmental structure.


Author(s):  
Oleg Оrlov ◽  
Maryna Ragulina

Estimation of changes in the microclimatic parameters of beech forests of the Stilsky Hillside, by measuring the water-temperature indicators of the soil regime and bryoindication, were performed. Fragmentation of forest causes significant changes in microclimatic parameters in bondary habitats areas, which leads to both biodiversity loss and a decrease of the unchanged forest areas. In fragmented beech forests, the influence of the edge effect on the water-temperature regime of soils is observed within a distance of 20-40 meters, but the eco-floristic structure of nemoral moss vegetation is stabilized only at a distance from 160 m. Thus, bryobiontes are a shown to be a sensitive marker of the microclimatic regime changes in a fragmented ecosystem. In the studied beeches Metzgeria furcata, Radula complanata, Anomodon attenuatus, A. viticulosus, Cirriphyllum crassinervium are indicators of the "interior forest". The determined amplitude of the edge effect indicates the fragmentation as a crucial factor on the small areas of forest and its role in the loss of climate-sensitive groups of biota, primarily mosses.


Check List ◽  
2016 ◽  
Vol 12 (6) ◽  
pp. 2007
Author(s):  
André V. Nunes ◽  
Vinicius S. Orsini

We report a range extension of the Grey Woolly Monkey, Lagothrix cana, from southwestern Amazonia, Mato Grosso, Brazil. Lagothrix cana was seen in a forest fragment near the “arc of deforestation”. This new record shows the need for conservation of forests in the region to protect this endangered species.


Author(s):  
Danilo Brito Novais ◽  
Joilson Silva Ferreira ◽  
Patrícia Anjos Bittencourt Barreto

Com a expansão da agricultura as florestas têm sido fragmentadas, modificando a dinâmica dos seus processos refletindo na fertilidade do solo. Esse estudo teve como objetivo avaliar o efeito de borda na fertilidade do solo em um fragmento florestal na região Sudoeste da Bahia. Para isso a área foi dividida em faixas verticais iniciando 50 metros após a borda, adentrando até 300 metros no fragmento. Em cada uma das faixas foram tomadas 3 amostras compostas nas profundidades de 0-5, 5-10, 10-20 cm. Analisando os atributos químico e calculando a soma de bases, CTC a pH7 e a saturação por bases (V%). Também foram quantificados os teores de carbono orgânico (COT) nas áreas de estudo. Foram observadas diferenças na fertilidade do solo da borda para o interior do fragmento.  Verificou-se que os atributos Ca2+, H++Al3+, S, T, COT foram os mais sensíveis em relação ao efeito de borda. A área semi-interna (SI) distando 150-200 metros, de maneira geral foi a que apresentou os maiores valores de fertilidade do solo, possivelmente devido aos maiores teores de matéria orgânica acumulada.  Soil fertility as edge effect indicator in a forest fragment, Vitória da Conquista, BahiaAbstract: With the expansion of agriculture forests have been fragmented, changing the dynamics of their processes reflecting soil fertility. This study aimed to evaluate the edge effect on soil fertility in a forest fragment in the Southwest Bahia region. For this area was divided into vertical strips starting 50 meters after the border, entering up to 300 meters in the fragment. In each of the tracks were taken 3 composite samples at depths of 0-5, 5-10, 10-20 cm. Analyzing the chemical attributes and calculating the sum of bases, CTC at pH 7 and base saturation (V%). Also the organic carbon levels were quantified (COT) in the study areas. Differences were observed at the edge of soil fertility into the fragment. It was found that attributes, Ca2+, H++Al3+, S, T, COT were the most sensitive in relation to the edge effect. The semi-internal area (SI) 150-200 meters distant in general was the one with the highest soil fertility values, possibly due to higher levels of accumulated organic matter.


2020 ◽  
Vol 7 (1) ◽  
pp. 18-24
Author(s):  
Karolayne Lemes D'Abadia ◽  
Ane Gabriele Vaz Souza ◽  
Gabriela Gomes da Silva Gomes da Silva ◽  
Murilo Silva Machado ◽  
Vagner Santiago do Vale Santiago do Vale ◽  
...  

Native forests have been suffering changes, such as fragmentation and edge effect, and these have implications for the dynamics of carbon within the same fragment, differentiating vegetation and soil. In this way, the work aimed to evaluate the hydro-microbiological attributes of the soil in rainy and dry periods, as well as to indicate if there is an edge effect in a seasonal semideciduous forest fragment. The study was carried out in a forest fragment in the area of the State University of Goiás, Ipameri Campus, consisting of three transects divided into three blocks from the edge. Sampling was performed in two periods of the year, rainy and dry, to determine the gravimetric soil water content (UG), microbial biomass carbon (MBC), basal respiration (BR), and the metabolic quotient (qCO2). The data were subjected to analysis of variance (F test), and when significant, the means were evaluated by the Tukey test at 5% probability. Response variations of microorganisms are closely related to the periods studied; the rainy season benefits the carbon incorporation activity, and the dry season stimulates the carbon release. Consequently, metabolic efficiency is more pronounced in the rainy season. The edge of the fragment only influenced the MBC, evidencing that disturbances caused at the extremity of fragment interfere with the C input in the microbial biomass.


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