scholarly journals Beta diversity and knowledge gaps of Colombia’s dry forests: implications for their conservation

Caldasia ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 1-11
Author(s):  
Gustavo H. Kattan ◽  
Camilo E. Sánchez ◽  
Catalina Vélez ◽  
Laura Ramírez ◽  
Marcela Celis

On a continental scale, Neotropical dry forests exhibit high plant beta diversity, forming twelve unique floristic provinces. Conserving this diversity requires plans to protect areas in each province, based on an understanding of their particular ecological conditions. In Colombia dry forest occurs in seven regions. We explored some challenges for conserving beta diversity at the country scale by downscaling the analysis and framing it in the context of the general knowledge status of the country’s dry forests, and particularly of seed dispersal. Our literature review revealed 178 studies, with an increase in publication rate in recent years. The Cauca Valley and the Caribbean region had the most publications. More than half of studies were species inventories of plants, birds, and bats, whereas only ten studies dealt with plant-animal interactions and five with secondary succession. Analyses on plants, birds, and bats revealed high levels of dissimilarity among regions. One-half of plant species in Colombia´s dry forests are dispersed by birds and mammals. Large-sized frugivorous birds and mammals are absent from remaining forest patches, which may negatively affect patterns of seed dispersal and secondary succession. Understanding the ecological and biogeographic factors at several scales, supported by local knowledge of the ecological processes that contribute to forest integrity, is key for the conservation of the unique and distinctive species composition of regional assemblages. A coordinated research effort that integrates knowledge of ecological processes at local to national scales is a priority.

2014 ◽  
Vol 31 (1) ◽  
pp. 57-68 ◽  
Author(s):  
R. Carlos Almazán-Núñez ◽  
María del Coro Arizmendi ◽  
Luis E. Eguiarte ◽  
Pablo Corcuera

Abstract:Few reports have described the relationship between the distribution of frugivorous birds and vegetation successional changes in dry forests. We assessed the abundance and behaviour of frugivorous birds in early, intermediate and mature dry forests in the Balsas river basin, Guerrero, Mexico. We selected nine dry-forest fragments, three fragments per stage, in these three stages of succession. We analysed the vegetation, estimated bird abundances in 10-min count periods, and recorded the way birds process fruits in circular plots (11–15 plots per fragment, 123 plots in total). Birds were classified as seed predators (15% of all individuals in this study), pulp consumers (15%) or legitimate dispersers (70%). Bird abundance was higher in mature forests in the dry season, while abundance and richness of legitimate dispersers and seed predators were positively related to vegetation complexity. Mature forests have a high vegetation complexity and a high cover ofBurseraspecies that produce fruit during the dry season. During the rains, abundance was higher in early-successional sites when the zoochorous plants produced fruit. Legitimate disperser migrants (i.e.Tyrannus vociferans, Myiarchus cinerascensandM. tyrannulus) were widespread, helping the establishment of zoochorous trees such asBurseraspp. in early-successional forests.


Author(s):  
Rocío de TORRE ◽  
María Dolores JIMÉNEZ ◽  
Álvaro RAMÍREZ ◽  
Ignacio MOLA ◽  
Miguel A. CASADO ◽  
...  

Plantings are commonly used in roadside reclamation for ornamental purposes and for increasing slope stability and road safety. However, the role of these plantings in restoring ecological processes, such as seed dispersal, has received little attention. We carried out a study to assess the potential role of plantings on roadside embankments to attract frugivorous birds and to enhance seed dispersal mediated by birds from the surrounding landscape. We examined: (1) bird species richness and abundance; (2) patterns of avian spatial distribution within embankments and (3) seed dispersal mediated by birds. Bird richness and abundance did not differ between embankments with and without plantings. However, birds were not distributed randomly within embankments, with levels of species richness and abundance for facultative frugivorous between 4.8–8 times higher in areas closer to plantings. An analysis of bird droppings showed that birds only dispersed seeds of the planted species since no seeds of woody plants from matrices were detected. These results suggest that plantings acted as selective bird attractors, providing food and perches for frugivorous species. Nevertheless, the scarcity of seed-dispersing birds in the surrounding agricultural landscape prevented plantings from enhancing seed dispersal and connectivity to adjacent habitat.


2019 ◽  
Vol 35 (4) ◽  
pp. 173-184 ◽  
Author(s):  
Fernanda Melo Gomes ◽  
Clemir Candeia de Oliveira ◽  
Roberta da Rocha Miranda ◽  
Rafael Carvalho da Costa ◽  
Maria Iracema Bezerra Loiola

AbstractTo better understand the role of seed banks in ecological succession of dry forests, we compared similarities between vegetation and seed banks and assessed the relative contributions of seed dispersal and persistence in chronosequences in the Brazilian semi-arid region. To sample the standing vegetation and the seed bank, we collected data in three sites with three successional ages in each one (5 y, 25 y and 45 y). A total of 180 soil samples (three sites × three successional ages × 10 plots × two components) were collected. The composition of the seed bank was assessed by the seedling emergence method. Of 166 species identified in the standing vegetation, only 50 (30.1%) were also present in the seed bank, resulting in low similarity (Jaccard index = 0.02–0.21) and reflecting the rarity of woody species and the dominance of annuals (71% of richness). The relative importance of seed persistence and seed dispersal to seed banks composition were balanced in most cases (difference was not rejected in four out six comparisons). Those results suggest that seed banks in tropical dry forests are largely the result of high dispersal rates and the persistence of allochthonous annual species that contribute to decoupling seed bank and vegetation composition.


2020 ◽  
Vol 13 (2) ◽  
pp. 171-176
Author(s):  
Daniel M Arruda ◽  
Luiz F S Magnago ◽  
Ricardo R C Solar ◽  
Reinaldo Duque-Brasil ◽  
Priscyla M S Rodrigues ◽  
...  

Abstract Aims Understanding the factors that control biodiversity distributions at different spatial scales has been a key challenge for conservation efforts. That biodiversity, reflected in differences in species compositions among sites (beta diversity), can be derived from species replacement (turnover) and is driven by multiple factors. Here, we sought to tackle this issue through two questions related to threatened Brazilian seasonally dry forests: (i) what is the contribution of species turnover to beta diversity? and (ii) which factors drive variations in species compositions among forest patches? Methods We sampled tree species and environmental variables (soils and climate) in 17 dry forest patches spaced almost 300 km apart. We used the beta diversity partitioning framework to determine the contribution of turnover. We used redundancy analysis, with properly controlled spatial structure, to assess the contributions of the environmental and spatial factors to the variations of the species composition. Important Findings Beta diversity among the patches was mainly represented by the turnover component (98.2%), with Simpson dissimilarity superior to other regions of the country (means of 0.89 and 0.71 in multiple site and pairwise measures, respectively). The environmental factors measured explained more than space, representing 30.3% of the variation of the species composition, of which 28.1% was nonspatially structured. We suggest that 300 km represents a threshold at which edaphic and climatic predictors have similar effects in determining community turnover (14.9% and 12.6%, respectively, without spatial structure). Thus, conservation strategies should be considered across landscapes to effectively protect tropical forest diversity, as even considering the different climatic aspects covered by the scale, landscaped edaphic varieties are important drivers of species turnover.


2004 ◽  
Vol 155 (3-4) ◽  
pp. 80-88 ◽  
Author(s):  
Klaus Ackermann

Wild growing yams (Dioscorea spp.) are an important supplementary food in Madagascar, especially during periods of rice shortage in the rainy season. Yams grow in dry forests and there is a particularly high occurrence of yam tubers in recently burned, open secondary forest formations. The study found that the uncontrolled harvest of yams can contribute to the degradation of dry forests due to the high quantity of wild yams harvested by the local population and the widespread practice of intentionally burning forests to increase yams production.


2021 ◽  
Author(s):  
Fabián Alejandro Rubalcava‐Castillo ◽  
Joaquín Sosa‐Ramírez ◽  
José de Jesús Luna‐Ruíz ◽  
Arturo Gerardo Valdivia‐Flores ◽  
Luis Ignacio Íñiguez‐Dávalos

2006 ◽  
Vol 1 (3) ◽  
pp. 318-322 ◽  
Author(s):  
Xianwen Lu ◽  
Kun Sun ◽  
Ruijun Ma ◽  
Hui Zhang ◽  
Xue Su ◽  
...  

Check List ◽  
2012 ◽  
Vol 8 (6) ◽  
pp. 1220 ◽  
Author(s):  
Junior T. Larreal ◽  
Gilson A. Rivas ◽  
Carlos Portillo-Quintero ◽  
Tito R. Barros

We present a commented taxonomic list of the reptiles found during herpetological surveys carried out in an isolated fragment of tropical dry forest located in the municipality of San Francisco, Zulia state, northwestern Venezuela between January-December 2011. We report a total of 24 species belonging to the order Squamata, distributed in 12 families and 21 genera. Colubridae is the most diverse family with six species, followed by Dipsadidae (four species), Boidae, Gymnophthalmidae, Phyllodactylidae and Teiidae with two species each, and finally Dactyloidae, Iguanidae, Elapidae, Gekkonidae, Sphaerodactylidae and Viperidae with a single species each. The species composition at this site matches what would be expected in a tropical dry forest in the region. Our study suggests that this isolated tropical dry forest fragment is the last refuge of the herpetofauna that once occupied much of the dry forests of the northern Maracaibo basin and should therefore be considered for conservation purposes.


2002 ◽  
Vol 62 (2) ◽  
pp. 339-346 ◽  
Author(s):  
J. RAGUSA-NETTO

Figs are a remarkable food resource to frugivores, mainly in periods of general fruit scarcity. Ficus calyptroceras Miq. (Moraceae) is the only fig species in a type of dry forest in western Brazil. In this study I examined the fruiting pattern as well as fig consumption by birds in F. calyptroceras. Although rainfall was highly seasonal, fruiting was aseasonal, since the monthly proportion of fruiting trees ranged from 4% to 14% (N = 50 trees). I recorded 22 bird species feeding on figs. In the wet season 20 bird species ate figs, while in the dry season 13 did. Parrots were the most important consumers. This group removed 72% and 40% of the figs consumed in the wet and dry seasons, respectively. No bird species increases fig consumption from dry to wet season. However, a group of bird species assumed as seed dispersers largely increases fig consumption from wet to dry season, suggesting the importance of this resource in the period of fruit scarcity. The results of this study points out the remarkable role that F. calyptroceras plays to frugivorous birds, in such a dry forest, since its fruits were widely consumed and were available all year round.


2016 ◽  
Vol 21 (2) ◽  
pp. 365-377
Author(s):  
Luis Eduardo Rojas Murcia ◽  
Juan E. Carvajal Cogollo ◽  
Javier Alejandro Cabrejo Bello

<p>Con el fin de caracterizar la distribución horizontal (repartición de los hábitats) y la utilización del recurso alimentario (tipo y tamaño de las presas) del ensamblaje de reptiles del bosque seco estacional al norte de la región Caribe de Colombia, en el departamento del Cesar, se realizaron cinco salidas de campo con una duración de doce días cada una. Los muestreos se realizaron en jornadas diurnas y nocturnas, en un diseño de transectos replicados a lo largo de diferentes hábitats que incluyeron: pastizales, bordes e interiores de bosque. Se realizaron análisis descriptivos de uso de hábitat en un perfil de vegetación por cada época climática y análisis de amplitud y sobreposición de nicho. Se registraron 38 especies de 14 familias del orden Squamata. Las especies se distribuyeron de manera homogénea entre zonas abiertas y boscosas. Se encontraron registros de 31 categorías de presa en 109 estómagos de seis especies de serpientes (61 estómagos) y siete de lagartos (48 estómagos) con un porcentaje de estómagos vacíos de 38 %. Las presas de mayor importancia para los lagartos fueron Coleoptera y Araneae, y para las serpientes fueron los anfibios. La mayoría de las especies presentaron un amplio espectro de dieta y entre especies similares, como entre Anolis auratus y A. gaigei, se presentó uso de recursos similares. En síntesis, el ensamblaje de reptiles presentó una distribución homogénea en los hábitats evaluados (áreas abiertas y boscosas) y el recurso alimentario fue variado entre las diferentes especies; la estacionalidad de la zona presenta un papel fundamental en la estructura del ensamblaje de reptiles, presentándose menos abundancia durante la época seca, tanto en las áreas abiertas como en las boscosas.</p><p><strong>Reptiles from the Seasonal Dry Forest the Caribbean Region: Distribution of Habitat and use of Food Resource</strong></p><p><strong>ABSTRACT</strong></p><p>We assessed the horizontal distribution and use of the food resource of the reptile’s assemblage of the seasonal tropical dry forest in the North of the Caribbean region of Colombia, department of Cesar. Five fieldtrips of 12 days each were performed, sampling was diurnal and nocturnal, following a transect design replicated along different habitats including grasslands, edge and interior of forest. We performed descriptive analyzes of habitat use, using a profile of vegetation by each climatic period; we also did an analysis of amplitude and niche overlap. We recorded 38 species of 14 families of the Squamata order. Species distributed evenly between open and forested areas. Record of 31 categories of prey in 109 stomachs of six species snakes (61 stomachs) and seven of lizards (48 stomachs) with a percentage of empty stomachs of 38 % was found. The preys of greater importance for the lizards were Coleoptera and Araneae and for snakes, amphibians. Most of the species presented a wide range of diet and between similar species, such as Anolis auratus and A. gaigei, found a similar use of resources. In summary, the assembly of reptiles presented a homogeneous distribution in the habitats evaluated (forested and open areas) and the food resource varied among the different species; the seasonality of the area plays a fundamental role on the structure of this reptile assembly with less abundance during the dry season in both, open and forested habitats.</p>


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