scholarly journals Analyzing the edge effects in a Brazilian seasonally dry tropical forest

2016 ◽  
Vol 76 (1) ◽  
pp. 169-175 ◽  
Author(s):  
D. M. Arruda ◽  
P. V. Eisenlohr
Keyword(s):  
Edge Effects ◽  
Tree Species ◽  
Forest Canopy ◽  
Canopy Cover ◽  
Dry Forest ◽  
Forest Edges ◽  
Dry Forests ◽  
Seasonally Dry ◽  
Dry Tropical Forests ◽  
Microclimatic Conditions

Abstract Due to the deciduous nature of dry forests (widely known as seasonally dry tropical forests) they are subject to microclimatic conditions not experienced in other forest formations. Close examinations of the theory of edge effects in dry forests are still rare and a number of questions arise in terms of this topic. In light of this situation we examined a fragment of the dry forest to respond to the following questions: (I) Are there differences in canopy cover along the edge-interior gradient during the dry season? (II) How does the microclimate (air temperature, soil temperature, and relative humidity) vary along that gradient? (III) How does the microclimate influence tree species richness, evenness and abundance along that gradient? (IV) Are certain tree species more dominant closer to the forest edges? Regressions were performed to address these questions. Their coefficients did not significantly vary from zero. Apparently, the uniform openness of the forest canopy caused a homogeneous internal microclimate, without significant differentiation in habitats that would allow modifications in biotic variables tested. We conclude that the processes of edge effect commonly seen in humid forests, not was shared with the dry forest assessed.

A relict new species of Oreobates (Anura, Strabomantidae) from the Seasonally Dry Tropical Forests of Minas Gerais, Brazil, and its implication to the biogeography of the genus and that of South American Dry Forests

Zootaxa ◽  
2012 ◽  
Vol 3158 (1) ◽  
pp. 37 ◽  
Author(s):  
MAURO TEIXEIRA ◽  
RENATA CECÍLIA AMARO ◽  
RENATO SOUSA RECODER ◽  
MARCO AURÉLIO DE SENA ◽  
MIGUEL TREFAUT RODRIGUES
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Minas Gerais ◽  
Dry Forest ◽  
Advertisement Call ◽  
Dry Forests ◽  
Mato Grosso ◽  
Seasonally Dry ◽  
Dry Tropical Forests ◽  
Molecular Phylogenetic

A new species of Oreobates is described from Cavernas do Peruaçu National Park, Januária, Minas Gerais state, in theAtlantic Dry Forests of Brazil. The new species is distinguished from all other Oreobates by having the following combi-nation of characters: large tympanum, discs broadly enlarged and truncate on Fingers III and IV, smooth dorsal skin, nup-tial pads absent, snout subacuminate, and a very short pulsatile (2–3 pulses) single-noted advertisement call with dominantfrequency of about 3150 Hz, and no harmonic structure. Molecular phylogenetic analyses using partial sequences of themitochondrial genes cytochrome b (cyt b) and 16S using multiple outgroups recovered the new species within Oreobatesand sister to O. heterodactylus. The latter species inhabits the Dry Forests of Mato Grosso (Cerrado) and Bolivia (Chiq-uitano forests), and is strictly associated to these habitats, which suggests a preterit connection between Chiquitano andAtlantic Dry Forests. The discovery of a new Oreobates in the Atlantic Dry Forest is of great importance for the conservation of these dry forests, as it is known only from this type of habitat.

scholarly journals El Niño-Southern Oscillation affects the water relations of tree species in the Yucatan Peninsula, Mexico

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge Palomo-Kumul ◽  
Mirna Valdez-Hernández ◽  
Gerald A. Islebe ◽  
Manuel J. Cach-Pérez ◽  
José Luis Andrade
Keyword(s):  
Water Potential ◽  
Leaf Area ◽  
Tropical Forests ◽  
Specific Leaf Area ◽  
Tree Species ◽  
Deciduous Species ◽  
Mature Trees ◽  
Seasonally Dry ◽  
Seasonally Dry Tropical Forests ◽  
Dry Tropical Forests

AbstractWe evaluated the effect of ENSO 2015/16 on the water relations of eight tree species in seasonally dry tropical forests of the Yucatan Peninsula, Mexico. The functional traits: wood density, relative water content in wood, xylem water potential and specific leaf area were recorded during the rainy season and compared in three consecutive years: 2015 (pre-ENSO conditions), 2016 (ENSO conditions) and 2017 (post-ENSO conditions). We analyzed tree size on the capacity to respond to water deficit, considering young and mature trees, and if this response is distinctive in species with different leaf patterns in seasonally dry tropical forests distributed along a precipitation gradient (700–1200 mm year−1). These traits showed a strong decrease in all species in response to water stress in 2016, mainly in the driest site. Deciduous species had lower wood density, higher predawn water potential and higher specific leaf area than evergreen species. In all cases, mature trees were more tolerant to drought. In the driest site, there was a significant reduction in water status, regardless of their leaf phenology, indicating that seasonally dry tropical forests are highly vulnerable to ENSO. Vulnerability of deciduous species is intensified in the driest areas and in the youngest trees.

scholarly journals A model for the importance of large arborescent palms in the dynamics of seasonally-dry amazonian forests

2005 ◽  
Vol 5 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Rodolfo Salm ◽  
Euphly Jalles-Filho ◽  
Cynthia Schuck-Paim
Keyword(s):  
Forest Regeneration ◽  
Forest Canopy ◽  
Forest Succession ◽  
Secondary Forest ◽  
Forest Disturbance ◽  
Dry Forest ◽  
Forest Patch ◽  
Seasonally Dry ◽  
Palm Trees ◽  
Amazonian Forests

In this study we propose a model that represents the importance of large arborescent palms in the dynamics of seasonally-dry Amazonian forests. Specifically, the model is aimed at guiding the investigation of the role of large arborescent palms on forest regeneration and succession. Following disturbance, the high level of luminosity reaching recently formed forest gaps favors the quick proliferation of shade-intolerant lianas that, by casting shade on the crowns of mature forest trees and increasing tree-fall probability, suppress forest succession. Due to their columnar architecture palm trees are, however, not severely affected by vines. As the palms grow, the canopy at the gaps becomes gradually higher and denser, progressively obstructing the passage of light, thus hindering the growth of shade-intolerant lianas and enabling late-successional tree development and forest regeneration. Owing to the long time associated with forest regeneration, the model cannot be tested directly, but aspects of it were examined with field data collected at an Attalea maripa-rich secondary forest patch within a matrix of well-preserved seasonally-dry forest in the Southeastern Amazon. The results indicate that (1) forest disturbance is important for the recruitment of large arborescent palms species, (2) these palms can grow rapidly after an event of disturbance, restoring forest canopy height and density, and (3) secondary forest dominated by palm trees species may be floristically similar to nearby undisturbed forests, supporting the hypothesis that the former has undergone regeneration, as purported in the model.

scholarly journals Climate change effects on early stages of Quercus ariifolia (Fagaceae), an endemic oak from seasonally dry forests of Mexico

2019 ◽  
Author(s):  
Ernesto I. Badano ◽  
Francisco A. Guerra-Coss ◽  
Erik J. Sánchez-Montes de Oca ◽  
Carlos I. Briones-Herrera ◽  
Sandra M. Gelviz-Gelvez
Keyword(s):  
Climate Change ◽  
Functional Traits ◽  
Rainy Season ◽  
Extinction Risk ◽  
Seedling Emergence ◽  
Dry Forest ◽  
Tree Seedlings ◽  
Dry Forests ◽  
Tree Recruitment ◽  
Seasonally Dry

Background and Aims: Tree recruitment in seasonally dry forests occurs during the rainy season. However, higher temperatures and reduced rainfalls are expected in these ecosystems because of climate change. These changes could induce drought conditions during the rainy season and affect tree recruitment. Plants subjected to thermal or water stress often display morphological and physiological shifts addressed to prioritize their survival. If recently emerged tree seedlings display these responses, this could improve their development during the rainy season and increase their survival chances. Our aim was to test whether recently emerged oak seedlings display these responses.Methods: We performed a field experiment with Quercus ariifolia, an oak species endemic to seasonally dry forests of central Mexico. At the beginning of the rainy season (September 2016), we sowed acorns of this species in control plots under the current climate and plots in which climate change was simulated by increasing temperature and reducing rainfall (CCS plots). Seedling emergence and survival were monitored every seven days during the rainy season (until January 2017). At the end of the experiment, we measured several functional traits on surviving seedlings and compared them between controls and CCS plots.Key results: Higher temperature and lower rainfall generated water shortage conditions in CCS plots. This did not affect emergence of seedlings but reduced their survival. Seedlings that survived in CCS plots displayed shifts in their functional traits, which matched with those of plants subjected to thermal and water stress.Conclusions: Our results suggest that climate change can increase the extinction risk of Q. ariifolia in seasonally dry forest of Mexico by reducing the survival of its offspring. Nevertheless, the results also suggest that seedlings developed under climate change conditions can display functional shifts that could confer them tolerance to increased drought.

scholarly journals Evaluating the Capability of Unmanned Aerial System (UAS) Imagery to Detect and Measure the Effects of Edge Influence on Forest Canopy Cover in New England

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1252
Author(s):  
Heather Grybas ◽  
Russell G. Congalton
Keyword(s):  
New England ◽  
Forest Canopy ◽  
Canopy Cover ◽  
Point Clouds ◽  
Forest Edge ◽  
P Value ◽  
Unmanned Aerial Systems ◽  
Forest Edges ◽  
Significant Edge ◽  
The Face

Characterizing and measuring the extent of change at forest edges is important for making management decisions, especially in the face of climate change, but is difficult due to the large number of factors that can modify the response. Unmanned aerial systems (UAS) imagery may serve as a tool to detect and measure the forest response at the edge quickly and repeatedly, thus allowing a larger amount of area to be covered with less work. This study is a preliminary attempt to utilize UAS imagery to detect changes in canopy cover, known to exhibit changes due to edge influences, across forest edges in a New England forest. Changes in canopy cover with increasing distance from the forest edge were measured on the ground using digital cover photography and from photogrammetric point clouds and imagery-based maps of canopy gaps produced with UAS imagery. The imagery-based canopy gap products were significantly more similar to ground estimates for canopy cover (p value > 0.05) than the photogrammetric point clouds, but still suffered overestimation (RMSE of 0.088) due to the inability to detect small canopy openings. Both the ground and UAS data were able to detect a decrease in canopy cover to between 45–50 m from the edge, followed by an increase to 100 m. The UAS data had the advantage of a greater sampling intensity and was thus better able to detect a significant edge effect of minimal magnitude effect in the presence of heavy variability.

New GPS technology improves fix success for large mammal collars in dense tropical forests

2009 ◽  
Vol 25 (2) ◽  
pp. 217-221 ◽  
Author(s):  
Mathias W. Tobler
Keyword(s):  
Forest Canopy ◽  
Temperate Forests ◽  
Radio Telemetry ◽  
Canopy Cover ◽  
Good Alternative ◽  
Dry Forest ◽  
Lowland Forest ◽  
Gps Collars ◽  
Poor Access ◽  
Lowland Forests

There have been few telemetry studies on large and medium-sized mammals from Neotropical lowland forests. This can partly be explained by the difficulty of tracking animals with radio-telemetry in these forests, often in remote areas with poor access due to limited transportation infrastructure. Researchers have been forced to follow their collared animals by aeroplane (Crawshaw 1995, Fragoso 1998, Rabinowitz & Nottingham 1986), but aerial telemetry is dangerous and involves difficult logistics and high costs. GPS (Global Positioning System) collars that allow the collection of data automatically at long intervals would be a good alternative. The effect of canopy cover on GPS fix success and location accuracy was of concern from the beginning and has been widely investigated in temperate forests (D'Eon 2003, Di Orio et al. 2003, Dussault et al. 1999, Moen et al. 1996, Rempel et al. 1995). All studies found a significant decrease in fix success and a large increase in location errors under forest canopy. Tropical lowland rain forests have a much denser canopy than temperate forests, and up to now the performance of GPS collars in tropical forest has been very poor. Rumiz & Venegas (2006) showed that while GPS collars worked in the dry forest of the Bolivian Chaco, they only obtained a successful fix in 1–3% of all attempts in the lowland forest of the Madidi National Park, Bolivia.

A new species of Atrypanius Bates, 1864 (Cerambycidae: Lamiinae: Acanthocinini) from Peruvian seasonally dry forests

2021 ◽  
Vol 2 (2) ◽  
pp. 21-26
Author(s):  
Gino Juárez-Noé
Keyword(s):  
New Species ◽  
Dry Forest ◽  
Dry Forests ◽  
Seasonally Dry ◽  
National University ◽  
Seasonally Dry Forest ◽  
A New Species

A new species of the genus Atrypanius Bates, 1864 is described from Peru: Atrypanius unpanus n. sp., based on specimens collected from the campus of the National University of Piura, an important area of seasonally dry forest in the Piura region, northwestern Peru.

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