Importance of riparian habitat for frugivorous bats in a tropical dry forest in western Mexico

2016 ◽  
Vol 33 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Mariana Zarazúa-Carbajal ◽  
Luis Daniel Avila-Cabadilla ◽  
Mariana Yólotl Alvarez-Añorve ◽  
Julieta Benítez-Malvido ◽  
Kathryn E. Stoner
Keyword(s):  
Species Richness ◽  
Vegetation Structure ◽  
Linear Models ◽  
Tropical Dry Forest ◽  
Habitat Type ◽  
Canopy Cover ◽  
Riparian Forests ◽  
Dry Forest ◽  
Local Fauna ◽  
Tropical Regions

Abstract:Riparian forests (RF) provide shelter, feeding resources and commuting areas and are fundamental for local fauna during long drought periods in tropical dry forests. Nevertheless, information regarding vertebrate ecology in tropical RF is scarce. The studies of bats in riparian habitats have been mostly focused on insectivorous assemblages in non-tropical regions. We contrasted the occurrence of frugivorous bats between RF and upland dry forest (UDF) in a Neotropical dry forest region and evaluated how vegetation structure modulates frugivorous bat presence and abundance. We sampled bat ensembles and vegetation structure in three UDF and three RF sites in Jalisco, Mexico. Bat ensembles and populations were analysed with generalized linear models, including as independent factors: (1) habitat and (2) vegetation attributes. In 72 nights we captured 840 bats belonging to seven species. No effect of habitat type or vegetation structure on species richness was found, but habitat type did affect bat species composition and abundance. Moreover, vegetation structural traits affected frugivorous bat abundance. Frugivore abundance was higher in RF than in UDF probably because RF provides greater resources and more roosting sites. Riparian forests also present more canopy cover and accessible flight spaces. Our results support the importance of RF for frugivorous bats in terms of abundance and composition. Additionally, the lack of differences in species richness between UDF and RF highlights the importance of both habitats for maintaining frugivorous bats, as well as the related ecosystem processes and services in tropical dry forest landscapes.

scholarly journals Multiple Factors Influence Seasonal and Interannual Litterfall Production in a Tropical Dry Forest in Mexico

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1241
Author(s):  
Hernán Morffi-Mestre ◽  
Gregorio Ángeles-Pérez ◽  
Jennifer S. Powers ◽  
José Luis Andrade ◽  
Astrid Helena Huechacona Ruiz ◽  
...  
Keyword(s):  
Linear Models ◽  
Tropical Dry Forest ◽  
Basal Area ◽  
Dry Forest ◽  
Maximum Temperature ◽  
Dry Forests ◽  
Evergreen Species ◽  
Flat Terrain ◽  
Litterfall Production ◽  
Successional Age

Litterfall production plays a fundamental role in the dynamics and function of tropical forest ecosystems, as it supplies 70–80% of nutrients entering the soil. This process varies annually and seasonally, depending on multiple environmental factors. However, few studies spanning several years have addressed the combined effect of climate variables, successional age, topography, and vegetation structure in tropical dry forests. In this study, we evaluated monthly, seasonal, and annual litterfall production over a five-year period in semideciduous dry forests of different successional ages growing on contrasting topographic conditions (sloping or flat terrain) in Yucatan, Mexico. Its relationship with climate and vegetation structural variables were also analyzed using multiple linear regression and generalized linear models. Litterfall was measured monthly in 12 litterfall traps of 0.5 m2 in three sampling clusters (sets of four 400 m2 sampling plots) established in forests of five successional age classes, 3–5, 10–17, 18–25, 60–79, and >80 years (in the latter two classes either on slopping or on flat terrain), for a total of 15 sampling clusters and 180 litterfall traps. Litterfall production varied between years (negatively correlated with precipitation), seasons (positively correlated with wind speed and maximum temperature), and months (negatively correlated with relative humidity) and was higher in flat than in sloping sites. Litterfall production also increased with successional age until 18–25 years after abandonment, when it attained values similar to those of mature forests. It was positively correlated with the aboveground biomass of deciduous species but negatively correlated with the basal area of evergreen species. Our results show a rapid recovery of litterfall production with successional age of these forests, which may increase with climate changes such as less precipitation, higher temperatures, and higher incidence of hurricanes.

scholarly journals Identifying Variables to Discriminate between Conserved and Degraded Forest and to Quantify the Differences in Biomass

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1020
Author(s):  
Yan Gao ◽  
Margaret Skutsch ◽  
Diana Laura Jiménez Rodríguez ◽  
Jonathan V. Solórzano
Keyword(s):  
Aboveground Biomass ◽  
Tropical Dry Forest ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Dry Forest ◽  
Rank Test ◽  
Degraded Forest ◽  
Forest Survey ◽  
Structural Variables

The purpose of this work was to determine which structural variables present statistically significant differences between degraded and conserved tropical dry forest through a statistical study of forest survey data. The forest survey was carried out in a tropical dry forest in the watershed of the River Ayuquila, Jalisco state, Mexico between May and June of 2019, when data were collected in 36 plots of 500 m2. The sample was designed to include tropical dry forests in two conditions: degraded and conserved. In each plot, data collected included diameter at breast height, tree height, number of trees, number of branches, canopy cover, basal area, and aboveground biomass. Using the Wilcoxon signed-rank test, we show that there are significant differences in canopy cover, tree height, basal area, and aboveground biomass between degraded and conserved tropical dry forest. Among these structural variables, canopy cover and mean height separate conserved and degraded forests with the highest accuracy (both at 80.7%). We also tested which variables best correlate with aboveground biomass, with a view to determining how carbon loss in degraded forest can be quantified at a larger scale using remote sensing. We found that canopy cover, tree height, and density of trees all show good correlation with biomass and these variables could be used to estimate changes in biomass stocks in degraded forests. The results of our analysis will help to increase the accuracy in estimating aboveground biomass, contribute to the ongoing work on REDD+, and help to reduce the great uncertainty in estimation of emissions from forest degradation.

Regeneration beneath a dioecious tree species (Spondias purpurea) in a Mexican tropical dry forest

2014 ◽  
Vol 30 (3) ◽  
pp. 265-268 ◽  
Author(s):  
Moisés Méndez-Toribio ◽  
Ana María González-Di Pierro ◽  
Mauricio Quesada ◽  
Julieta Benítez-Malvido
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Seedling Recruitment ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Total Density ◽  
Dioecious Plant ◽  
Nucleation Sites ◽  
The Pacific ◽  
Spondias Purpurea

Abstract:In dioecious plant species different frugivore activity between genders may influence the abundance and richness of the seedling banks underneath their canopies throughout seed removal and dispersal. In the tropical dry forest of Chamela, on the Pacific Coast of Mexico, the role of S. purpurea female trees as nucleation sites of regeneration was investigated. The standing density, species richness and dispersal syndrome of woody seedlings (i.e. trees and shrubs, 10–100 cm tall) recruited underneath and outside the canopy of 10 male and 10 female S. purpurea trees were recorded in a total of 160 1-m2 plots. Total density was greater in seedling communities associated with female trees (i.e. underneath and outside their canopies) as compared with male trees (231 vs. 153 seedlings, respectively); whereas overall species richness was greater underneath female canopies. Further, the density of zoochorous species were greater underneath the canopy of S. purpurea females (range = 0–5 plants m−2), than elsewhere (outside female canopies, range = 0–3 plants m−2; underneath and outside male canopies, range = 0–2 plants m−2), suggesting a directional dispersal bias towards them. Females of dioecious plant species may act as nucleation sites of initial seedling recruitment in tropical dry forests.

scholarly journals Accuracy, limitations and cost-efficiency of eDNA-based community survey in tropical frogs

2017 ◽  
Author(s):  
Miklós Bálint ◽  
Carsten Nowak ◽  
Orsolya Márton ◽  
Steffen U. Pauls ◽  
Claudia Wittwer ◽  
...  
Keyword(s):  
Community Structure ◽  
Cost Efficiency ◽  
Life Histories ◽  
Large Scale ◽  
Data Interpretation ◽  
Dry Forest ◽  
Ecological Value ◽  
Local Fauna ◽  
Tropical Regions ◽  
High Diversity

AbstractRapid environmental change in highly biodiverse tropical regions demands efficient biomonitoring programs. While existing metrics of species diversity and community composition rely on encounter-based survey data, eDNA recently emerged as alternative approach. Costs and ecological value of eDNA-based methods have rarely been evaluated in tropical regions, where high species richness is accompanied by high functional diversity (e.g. the use of different microhabitats by different species and life-stages). We first tested whether estimation of tropical frogs’ community structure derived from eDNA data is compatible with expert field assessments. Next we evaluated whether eDNA is a financially viable solution for biodiversity monitoring in tropical regions. We applied eDNA metabarcoding to investigate frog species occurrence in five ponds in the Chiquitano dry forest region in Bolivia and compared our data with a simultaneous visual and audio encounter survey (VAES). We found that taxon lists and community structure generated with eDNA and VAES correspond closely, and most deviations are attributable to different species’ life histories. Cost efficiency of eDNA surveys was mostly influenced by the richness of local fauna and the number of surveyed sites: VAES may be less costly in low-diversity regions, but eDNA quickly becomes more cost-efficient in high-diversity regions with many sites sampled. The results highlight that eDNA is suitable for large-scale biodiversity surveys in high-diversity areas if life history is considered, and certain precautions in sampling, genetic analyses and data interpretation are taken. We anticipate that spatially extensive, standardized eDNA biodiversity surveys will quickly emerge in the future.

scholarly journals Diversidad de aves en fragmentos de bosque seco tropical en paisajes ganaderos del Departamento de Córdoba, Colombia

2017 ◽  
Vol 65 (4) ◽  
pp. 1625
Author(s):  
Jose Alejandro Vergara Paternina ◽  
Jesús Ballesteros Correa ◽  
Carlos González Charrasquiel ◽  
Juan C. Linares Arias
Keyword(s):  
Species Richness ◽  
Secondary Forest ◽  
Tropical Dry Forest ◽  
Bird Species ◽  
Sampling Period ◽  
Shannon Index ◽  
Dry Forest ◽  
Tree Cover ◽  
Bird Diversity ◽  
Secondary Forests

In Colombia the tropical dry forest is one of the most threatened and least known ecosystems; these have been impacted by different transformation processes and habitat fragmentation, which have affected bird conditions and survival. This research evaluated the influence of landscape elements (forest and pastures with different tree covers) on bird diversity in the tropical dry forest of Córdoba, Colombia. The study was developed within an extensive livestock landscape to characterize the avifauna in four habitat types formed by fragments of secondary forests with different tree cover: secondary forest, pastures with high tree cover, pastures with low tree cover and only pastures. The influence of tree cover on bird diversity was evaluated with monthly samplings in 200 m long transects (per habitat), with two observation intervals (6:00 - 9:00 and 15:00-18:00), from September 2011 to May 2012. A total of 6 667 individuals belonging to 180 species and 48 families of birds were registered. The most abundant species were Columbina talpacoti (5.37 %), Brotogeris jugularis (5.14 %), Tyrannus melancholicus (4.81 %) and Bubulcus ibis (4.80 %). The most abundant family was Tyrannidae (16.4 %), followed by Psitacidae (9.0 %) and Columbidae (8.2 %). The family with the highest number of species was Tyrannidae with 28 species, followed by Accipitridae and Icteridae with 10 species each. The greatest species richness was present in the secondary forest habitat, followed by the pastures with high tree cover, and pastures with low cover. The lowest abundance and species richness was found in pastures without tree cover with significant differences between the habitats (Fisher, p <0.05). According to the Shannon index, the diversity of birds was higher in the secondary forests. In contrast, the lowest diversity was found in pastures without tree cover. The greatest species richness occurred in the months of October and November. In the rest of the sampling period, the number of recorded species and individuals showed some stability. The importance of trees presence in extensive livestock areas was evidenced because they help to contain an important diversity of bird species, and they also generate connectivity among fragments of secondary forests in the cattle landscape.

scholarly journals Taking a deeper look: Quantifying the differences in fish assemblages between shallow and mesophotic temperate rocky reefs

2018 ◽  
Author(s):  
Joel Williams ◽  
Alan Jordan ◽  
David Harasti ◽  
Peter Davies ◽  
Tim Ingleton
Keyword(s):  
Species Richness ◽  
Linear Models ◽  
Fish Assemblages ◽  
Habitat Type ◽  
Rocky Reefs ◽  
Temperate Reefs ◽  
Video Systems ◽  
Parsimonious Model ◽  
Using Data ◽  
Species Richness And Abundance

AbstractThe spatial distribution of a species assemblage is often determined by habitat and climate. In the marine environment, depth can become an important factor as degrading light leads to changes in the biological habitat structure. To date, much of the focus of ecological fish research has been based on reefs in less than 40 m with little research on the ecological role of mesophotic reefs. We deployed baited remote underwater stereo video systems (stereo-BRUVS) on temperate reefs in two depth categories: shallow (20-40m) and mesophotic (80-120m), off Port Stephens, Australia. Sites were selected using data collected by swath acoustic sounder to ensure stereo-BRUVS were deployed on reef. The sounder also provided rugosity, slope and relief data for each stereo-BRUVS deployment. Multivariate analysis indicates that there are significant differences in the fish assemblages between shallow and mesophotic reefs, primarily driven by Ophthalmolepis lineolatus and Notolabrus gymnogenis only occurring on shallow reefs and schooling species of fish that were unique to each depth category: Atypichthys strigatus on shallow reefs and Centroberyx affinis on mesophotic reefs. While shallow reefs had a greater species richness and abundance of fish when compared to mesophotic reefs, mesophotic reefs hosted the same species richness of fishery targeted species. Chrysophrys auratus (pink snapper) and Nemodactylus douglassii (grey morwong) are two highly targeted species in this region. While C. auratus was numerically more abundant on shallow reefs, mesophotic reefs provide habitat for larger fish. In comparison, N. douglassii were evenly distributed across all sites sampled. Generalized linear models revealed that depth and habitat type provided the most parsimonious model for predicting the distribution of C. auratus, while habitat type alone best predicted the distribution of N. douglassii. These results demonstrate the importance of mesophotic reefs to fishery targeted species and therefore have implications for informing the management of these fishery resources on shelf rocky reefs.

scholarly journals A universal scaling method for biodiversity-ecosystem functioning relationships

2019 ◽  
Author(s):  
K.E. Barry ◽  
G.A. Pinter ◽  
J.W. Strini ◽  
K. Yang ◽  
I.G. Lauko ◽  
...  
Keyword(s):  
Species Richness ◽  
Biomass Production ◽  
Ecosystem Functioning ◽  
Spatial Scales ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Additional Species ◽  
Spatial And Temporal Scales ◽  
Natural Systems ◽  
Species Area

SummaryGlobal biodiversity is declining at rates faster than at any other point in human history. Experimental manipulations of biodiversity at small spatial scales have demonstrated that communities with fewer species consistently produce less biomass than higher diversity communities. However, understanding how the global extinction crisis is likely to impact global ecosystem functioning will require applying these local and largely experimental findings to natural systems at substantially larger spatial and temporal scales. Here we propose that we can use two simple macroecological patterns – the species area curve and the biomass-area curve – to upscale the species richness-biomass relationship. We demonstrate that at local spatial scales, each additional species will contribute more to biomass production with increasing area sampled because the species-area curve saturates and the biomass-area curve increases monotonically. We use species-area and biomass-area curves from a Minnesota grassland and a Panamanian tropical dry forest to examine the species richness – biomass relationship at three and ten sampling extents, respectively. In both datasets, the observed relationship between biodiversity and biomass production at every sampling extent was predicted from simple species-area and biomass-area relationships. These findings suggest that macroecological patterns like the species-area curve underpin the scaling of biodiversity-ecosystem functioning research and can be used to predict these relationships at the global scales where they are relevant for species loss.

Sign in / Sign up

Export Citation Format

Share Document