scholarly journals Estructura, composición y diversidad de la selva baja caducifolia del Cerro Verde, Nizanda (Oaxaca), México

2017 ◽  
pp. 19 ◽  
Author(s):  
José A. Gallardo-Cruz ◽  
Jorge A. Meave ◽  
Eduardo A. Pérez-García
Keyword(s):  
Species Richness ◽  
Forest Cover ◽  
Conservation Status ◽  
Tropical Dry Forest ◽  
Basal Area ◽  
Floristic Composition ◽  
Dry Forest ◽  
Tropical Region ◽  
Mean Values ◽  
Seasonally Dry

In this study we describe the structure, floristic composition, and diversity of the tropical dry forest established on the Cerro Verde (Verde Hill), located at Nizanda (Isthmus of Tehuantepec, Oaxaca, Mexico). We censused woody plants with DBH Ɛ 1 cm (upper stratum) present in 30 100-m2 plots, and in five 4-m2 subplots within each of them, those plants with height > 30 cm but < 1 cm DBH (lower stratum). A total of 194 species belonging to 52 families were recorded. Species richness was identical in both strata (145 species), each contributing exclusively with ca. 25% of total recorded richness. Leguminosae was the most speciose family (27), followed by Asteraceae (20) and Euphorbiaceae (18). The most frequent species were Bursera simaruba + B. aff. cinerea (not distinguished in the field), Euphorbia schlechtendalii, Pilosocereus collinsii and Capparis verrucosa. Average richness by plot was 30 species. Mean values of indices based on species richness and abundances (Berger-Parker = 0.20;  Simpson = 0.09; Fisher’s[= 9.47; Shannon = 2.78; eveness = 0.82) indicated a high diversity and consequently a low dominance in this forest. Extrapolated values showed a total (upper + lower strata) density of 23,950 ind. ha-1 (830 ind. ha-1 with DBH Ɛ 10 cm), a forest cover of 446.7%, and a basal area of 53 m2 ha-1. Mean height of those individuals accounting for 10% of the highest trees by plot was 9.1 m. Tropical dry forest structure at Cerro Verde is comparable to other Mexican communities within the seasonally dry tropical region and indicates a good conservation status. This feature, together with its particular floristic composition, makes of this area a high priority site which requires inclusion in a formal conservation scheme.

Dry forests of the Galápagos: a comparative assessment of a World Heritage Site

2020 ◽  
Vol 26 (2) ◽  
pp. 161
Author(s):  
Thomas W. Gillespie ◽  
Gunnar Keppel ◽  
Chelsea M. Robinson ◽  
Gonzalo Rivas-Torres
Keyword(s):  
Species Richness ◽  
Woody Plants ◽  
Native Species ◽  
Forest Cover ◽  
Conservation Status ◽  
Dry Forest ◽  
World Heritage Site ◽  
Dry Forests ◽  
Forest Region ◽  
The Pacific

Despite worldwide knowledge of the importance of the Galápagos archipelago, there is little comparative plot data from the forests in the dry regions. We examined patterns of woody plant (≥2.5cm diameter at breast height (DBH)) species richness and structure using Gentry’s transect method (0.1ha) on the three largest islands in the Galápagos. We identified the conservation status of woody plants within the dry forest region, assessed forest cover and change in the region, and compared field results to other tropical dry forests in the Pacific. Of the 22 species encountered (11 native, 11 endemic), there were no non-native species and only one threatened species. Isabela, Santa Cruz and San Cristóbal have similar overall levels of species, genera, family and liana richness per site, but significantly different tree species richness, density and tree height per transect. Geospatial databases identified 51 species (native 40%, endemic 60%) of woody plants (≥2.5cm DBH) within the dry forest region of the Galápagos and 13 species (10 from the genus Scalesia) on the IUCN Red List. There is an estimated 551.97km2 of dry forest in the Galápagos and there has been little change (<0.01%) in forest cover from 2000 to 2015. Dry forests of the Galápagos have similar levels of species richness to Hawaii and the Marquesas but contain lower densities, basal areas and tree heights than other dry forests in the Pacific. These dry forests appear to be the best preserved and protected tropical dry forest in the Pacific.

Secondary forest succession in a tropical dry forest: patterns of development across a 50-year chronosequence in lowland Bolivia

2002 ◽  
Vol 18 (1) ◽  
pp. 53-66 ◽  
Author(s):  
DEBORAH K. KENNARD
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Stand Structure ◽  
Secondary Forest ◽  
Tropical Dry Forest ◽  
Basal Area ◽  
Forest Stand ◽  
Dry Forest ◽  
Stem Density ◽  
Mature Forest

Stand structure, species richness and population structures of tree species were characterized in 12 stands representing 50 y of succession following slash-and-burn agriculture in a tropical dry forest in lowland Bolivia. Estimates of tree species richness, canopy cover and basal area reached or surpassed 75% of mature forest levels in the 5-, 8-, and 23-y-old stands respectively. Total stem density of the 50-y-old stand was almost twice that of the mature forest stand. This rapid recovery may be due to a high percentage of sprouting tree species, potentially high seed fall into abandoned fields, or the disturbance history of the mature stand. The even-aged size-class structures, dominance of long-lived pioneers, and presence of charcoal and pottery shards in soils of the mature forest stand suggest it formed after a severe disturbance, possibly fire of anthropogenic origin.

scholarly journals Herpetofaunal diversity in a tropical dry forest on the Central Coast of Oaxaca, Mexico

2019 ◽  
Vol 29 ◽  
pp. 1-11
Author(s):  
Jesús García Grajales ◽  
Yolanda López-López ◽  
Alejandra Buenrostro Silva
Keyword(s):  
Conservation Status ◽  
Tropical Dry Forest ◽  
Similarity Index ◽  
Dry Forest ◽  
Central Coast ◽  
Amphibian Species ◽  
Baseline Information ◽  
Threatened Habitats ◽  
High Diversity ◽  
Pueblo Viejo

The dry forest is an ecosystem with a relatively high diversity of species. It is also one of the most threatened habitats. This research was carried out between January and November 2010 aiming to describe species richness, composition, and conservation status of the herpetofauna in the Yerbasanta micro-basin in the Central Coast of Oaxaca. Standard visual encounter surveys were used to observe herpetofaunal community in four locations of the micro-basin. Five amphibian species and 37 reptiles species were found. The Shannon-Wienner index showed that Pueblo Viejo had the highest value of diversity, followed by Unión, and the remainder localities had lower values. The similarity index was moderate between locations. Among the registered species, 12 can be classified under some conservation status. These results also suggest that this region can maintain a significant number of herpetofauna species. Additionally, this research represents baseline information that contributes to other studies.

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.

Scenarios of the Tropical Dry Forest of Purulia District West Bengal

2020 ◽  
pp. 254-267
Author(s):  
Masuma Begum ◽  
Niloy Pramanick ◽  
Anirban Mukhopadhyay ◽  
Sayani Datta Majumdar
Keyword(s):  
Land Cover ◽  
Forest Cover ◽  
Vegetation Indices ◽  
Atmospheric Correction ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Training Data ◽  
Change Dynamics ◽  
Land Cover Map ◽  
Purulia District

In this chapter, satellite images of the years 1995, 2005, and 2015 of LANDSAT have been used. After pre-processing (geometric correction and atmospheric correction using FLAASH, LULC change dynamics have been assessed to estimate the changes in total forest cover in Purulia district through an unsupervised K-means classification scheme. To evaluate the health status, vegetation indices, namely NDVI, SAVI, and CVI, have been used. The increase in NDVI, SAVI, and CVI values was inferred as no significant degradation of Purulia forest cover. Moreover, future scenarios have been predicted by implementing a CA-MARKOV model. Using the land cover map of 1995 as the base map, and from 1995 to 2005 as training data, a land cover map of 2015 has been generated which in turn validated by the actual land cover of 2015. After validation, prediction of land cover was possible for the years 2035 and 2050. The prediction suggested that forest area will increase by approximately 4% from 2015 to 2035 and by 3% from 2035 to 2050.

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.

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