scholarly journals Spatial distribution of Guaiacum sanctum (Zygophyllaceae) seedlings and saplings relative to canopy cover in Palo Verde National Park, Costa Rica

2013 ◽  
Vol 61 (3) ◽  
Author(s):  
Eric J. Fuchs ◽  
Tatiana Robles ◽  
James L. Hamrick
2019 ◽  
Vol 67 (6) ◽  
Author(s):  
Ulises Balza ◽  
Roland Charles De Gouvenain

Introduction: The Lignum-vitae (Guaiacum sanctum; Zygophyllaceae) of Mesoamerica and the Greater Antilles, is threatened over much of its range. We evaluated whether a G. sanctum population in the Palo Verde National Park of Costa Rica is viable in the long term. Methods: Using two demographic studies, one in 1997 and the other in 2017, we estimated survival and fecundity rates for each tree age class, population growth rate (lambda), and vital rates elasticities, and we used a density-independent deterministic population model to project the long-term trend of that population. Results: The estimated vital rates during the last 20 years suggested that this population is rapidly decreasing. Although some age classes increased in abundance, seedlings are rare and the plants that recruited in 1997 have not yet reached reproductive maturity. Our results suggest that the current abundance of G. sanctum within the national park may not be a good indicator of its long-term conservation status, and from our population viability analysis, we estimated that the population we studied would decrease to less than 1 % of its current size within the next 200 years. Conclusions: Landscape-scale ecosystem deterioration affecting the greater PVNP region, such as loss of seed dispersers and suppression of disturbances, may offset the passive protection of G. sanctum within park boundaries. Relying on the overall strict protection afforded by the location of the population within the Palo Verde National Park may not be sufficient to conserve this population of G. sanctum. We recommend that more proactive experimental protection and/or restoration measures, possibly including disturbance treatments, be implemented within a research program.


2018 ◽  
Vol 10 (9) ◽  
pp. 1427 ◽  
Author(s):  
Papia Rozario ◽  
Buddhika Madurapperuma ◽  
Yijun Wang

This study develops a site specific burn severity modelling using remote sensing techniques to develop severity patterns on vegetation and soil in the fire prone region of the Palo Verde National Park in Guanacaste, Costa Rica. Terrain physical features, soil cover, and scorched vegetation characteristics were examined to develop a fire risk model and to quantify probable burned areas. Spectral signatures of affected areas were captured through multi-spectral analysis; i.e., Normalized Burn Ratio (NBR), Landsat derived differenced Normalized Burn Ratio (dNBR) and relativized dNBR (RdNBR). A partial unmixing algorithm, Mixture Tuned Matched Filtering (MTMF) was used to isolate endmembers for scorched vegetation and soil. The performance of dNBR and RdNBR for predicting ground cover components was acceptable with an overall accuracy of 84.4% and Cohen’s Kappa 0.82 for dNBR and an overall accuracy of 89.4% and Cohen’s Kappa 0.82 for RdNBR. Landsat derived RdNBR showed a strong correlation with scorched vegetation (r2 = 0.76) and moderate correlation with soil cover (r2 = 0.53), which outperformed dNBR. The ecologically diverse and unique park area is threatened by wetland fires, which pose a potential threat to various species. Human induced fires by poachers are a common occurrence in such areas to gain access to these species. This paper aims to prioritize areas that are at a higher risk from fire and model spatial adaptations in relation to the direction of fire within the affected wetlands. This assessment will help wildlife personnel in managing disturbed wetland ecosystems.


2021 ◽  
Vol 16 (2) ◽  
pp. 273-287
Author(s):  
José M. Mora ◽  
Franklin E. Castañeda

Habitat selection is the process whereby individuals preferentially use, or occupy, a non-random set of available habitats. At the same time, nest site selection is defined as the placement of eggs by females at sites differing from random sites within a delimited area. We located 59 nests of the mud turtle Kinosternon scorpioides in Palo Verde National Park (PVNP) in Northwestern Costa Rica. We compared eight microhabitat variables at nest sites against those at random sites. Females significantly placed their eggs at sites with more understory, leaf litter cover, and greater leaf litter depth than in random sites. Additionally, females selected sites with lower air and soil temperature and lower air humidity. Palo Verde NP is subject to active management actions designed to control invasive plant species in the wetland, namely cattail (Thypha domingensis Pers.). The main actions have been cattle grazing, controlled fires, and mechanical crushing of vegetation. We found that habitat quality in nesting areas is being threatened by at least one of these actions: cattle grazing. This is detrimental for three microhabitat traits that turtles select for nesting sites: understory cover, leaf litter cover, and leaf litter depth. The continued degradation of microhabitats at nesting areas of K. scorpioides at PVNP could be affecting recruitment due to embryo survivorship.


2010 ◽  
Vol 41 (6) ◽  
pp. 567-575 ◽  
Author(s):  
Rodrigo A. Arriagada ◽  
Erin O. Sills ◽  
Subhrendu K. Pattanayak ◽  
Frederick W. Cubbage ◽  
Eugenio González

2015 ◽  
Vol 7 (2) ◽  
pp. 279-286
Author(s):  
Daniel Ramírez-Arce

Centruroides margaritatus is one of the most common scorpions in Costa Rica, however almost null ecological or population-based studies have been conducted. Therefore, the objective of the present study was to characterize the habitat use and surface activity of this species in Palo Verde National Park, Costa Rica. Scorpions were searched intensively along transects at three sites: road, camp and forest. The microhabitat in each capture was characterized and the surface activity of the scorpions was recorded at the time of capture. C. margaritatus was found in different microhabitats: soil, leaf litter, herbaceous plants, shrubs, trees, and under rocks and fallen logs, with a preference to use vegetation to heights less than 50 cm. The scorpions were in an ambush behavior most of the times and were observed mostly in the vegetation, while they were in a resting behavior mainly under fallen trunks and rocks. The use of vegetation can represent a strategy to obtain food and also be in a safe place against predators. Nevertheless, the species adaptability provides the ease of using many microhabitats in sites where vegetation is scarce. While the study period was short, this research provides the first observations about the habitat use of this species in Costa Rica, which serves as a basis for future investigation.


2006 ◽  
Vol 37 (4) ◽  
pp. 549-552 ◽  
Author(s):  
Mario Santoro ◽  
Giovanna Hernández ◽  
Magaly Caballero ◽  
Fernando García

1999 ◽  
Vol 15 (5) ◽  
pp. 589-602 ◽  
Author(s):  
Vidya R. Athreya

Strangler fig density varied considerably in the evergreen forest of Karian Shola National Park, southern India, with 11 individuals ha−1 in an open trail area and 5.6 individuals ha−1 within the primary forest area. The index of light level was assessed by estimating the percentage of upper canopy cover along the longitudinal centre of ten, 500-m × 20-m plots in each of the two areas of the evergreen forest. However, the increase in strangler fig density was not correlated to light levels but was significantly correlated to the numbers of their main host species in the two areas. In Karian Shola National Park, strangler figs occurred predominantly on a few host species with 20 and 50% of strangler figs growing on Vitex altissima, Diospyros bourdilloni and Eugenia/Syzygium spp. in the primary forest and trail areas respectively. Both young and established strangler figs were recorded mainly on larger individuals of their host trees indicating that older host trees are likely to be more suitable for the germination and establishment of strangler figs. The reason for the above could be the higher incidence of humus-filled and decaying regions in the older host trees which would provide an assured supply of nutrients for the establishing strangler fig.


2021 ◽  
Vol 6 (1) ◽  
pp. 58612
Author(s):  
Silvi Dwi Anasari ◽  
Wulan Pusparini ◽  
Noviar Andayani

The distribution of a species can help guide the protection activities in their natural habitat. Conversely, the lack of information on this distribution makes the protection strategy of this species difficult. The research was conducted in Way Canguk Research Station, Bukit Barisan Selatan National Park from January until March 2018. The purposes of this research were to create a distribution prediction map of Sunda pangolin (Manis javanica) and estimating the environment variables that most influenced the probability of the distribution. Fourteen points of camera trap coordinates were used for presence data with nine types of environment variables such as elevation, slope, understorey, canopy cover, distance from roads, distance from rivers, distance from villages, food source, and distance from the threat. The result of maxent showed an Area Under the Curve (AUC) value of 0.909 categorized as very good. The highest probability of Sunda pangolin distributions was in the Pemerihan Resort and Way Haru Resort area, while the dominant environmental variables included the distance from the village, the canopy cover, and the distance from threat with the value 47.7; 25.85; and 15.8%, respectively. Prediction maps and environment variables can help to identify the population of Sunda pangolin in the wild and can provide input for the national parks to prioritize protection areas for Sunda pangolin from the increased poaching.


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