scholarly journals Dynamic and growth of the forests of the Isla del Coco National Park, Costa Rica

2020 ◽  
Vol 68 (S1) ◽  
pp. S89-S102
Author(s):  
Rafael Bonilla-Mata ◽  
Luis Guillermo Acosta-Vargas

Introduction: Islands are essential for world biodiversity. Isla del Coco National Park is an oceanic island in which a tropical rain forest grows; however, its ecology and the effect of introduced species are poorly understood. Objective: To evaluate the mortality, recruitment, regeneration, and growth of forest canopy species. Methods: We measured 15 permanent sampling plots (PSP), nine in the Premontane Pluvial Rainforest (PPR), and six in the Cloud Forest (CF); trees with DBH > 5 cm (diameter at breast height) were measured. The sampling regeneration was done within every PSP, along two transects of 1 X 50 m. Data analyses were performed using data obtained in 2006 and 2012 as baseline. Results: In the period 2012-2017, the annual mortality rate in the PPR was 5.75 % and for CF 6.31 %. The yearly recruitment rate in the PPR was 5.38 %, and 5.90 % for CF. For the PPR the total registered regeneration was 5 656 individuals and 8 700 for the CF. Sacoglottis holdridgei reported the highest mortality and the lowest values of recruitment and regeneration. Forest structure fits the inverted J model for most of the tropical forests. Sacoglottis holdridgei define the forest population structure above DBH > 20 cm. But, diameters under 20 cm are strongly influenced by H. succosa, because it reported the highest abundance of regeneration and recruitment. The annual average increase in diameter between forest was statically different (p = 0.0414; N = 15), 0.36 cm/year in the PPR, and 0.33 cm/year the in CF. Conclusions: The PPR and CF differ in the patterns of mortality, recruitment, and regeneration, confirming the uniqueness of these ecosystems. More successful regeneration of H. succosa will lead to changes in structure and composition of forests, mainly PPR. The changes in forest structure will have a strong impact on epiphytic flora, microclimate conditions, and bird nesting such as Gygis alba (White Tern) due to the loss of mature trees of Sacoglottis. The low regeneration of S. holdridgei is associated with the presence of introduced herbivores, their management is needed for restoring the forest.

Zootaxa ◽  
2013 ◽  
Vol 3630 (2) ◽  
pp. 270-290 ◽  
Author(s):  
FRANK FIERS ◽  
MERLIJN JOCQUE

Five different species of Copepoda were extracted from a leaf litter sample collected on the top (at 2000 m a.s.l.) of a cloud forested mountain in El Cusuco National Park, Honduras. Three of them, one Cyclopidae and two Canthocamptidae are new to science, and are described herein. Olmeccyclops hondo sp. nov. is the second representative thus far known of this New World genus. Moraria catracha sp. nov. and Moraria cusuca sp. nov. are the first formally described members of the genus occurring in Central America. The concept of a “Moraria-group” is considered to be an artificial grouping and is limited here to the genera Moraria and Morariopsis only. The distributional range of this group is essentially Holarctic, with the mountainous regions inHonduras, and probably in westNicaragua, as the southernmost limits in theNew World.


2016 ◽  
Vol 50 (2) ◽  
pp. 337-344 ◽  
Author(s):  
Jorge Brito M. ◽  
Reed Ojala-Barbour ◽  
Diego Batallas R. ◽  
Ana Almendáriz C.

2021 ◽  
Author(s):  
Yupan Zhang ◽  
Yuichi Onda ◽  
Hiroaki Kato ◽  
Xinchao Sun ◽  
Takashi Gomi

<p>Understory vegetation is an important part of evapotranspiration from forest floor. Forest management changes the forest structure and then affects the understory vegetation biomass (UVB). Quantitative measurement and estimation of  UVB is a step cannot be ignored in the study of forest ecology and forest evapotranspiration. However, large-scale biomass measurement and estimation is challenging. In this study, Structure from Motion (SfM) was adopted simultaneously at two different layers in a plantation forest made by Japanese cedar and Japanese cypress to reconstruct forest structure from understory to above canopy: i) understory drone survey in a 1.1h sub-catchment to generate canopy height model (CHM) based on dense point clouds data derived from a manual low-flying drone under the canopy; ii) Above-canopy drone survey in whole catchment (33.2 ha) to compute canopy openness data based on point clouds of canopy derived from an autonomous flying drone above the canopy. Combined with actual biomass data from field harvesting to develop regression models between the CHM and UVB, which was then used to map spatial distribution of  UVB in sub-catchment. The relationship between UVB and canopy openness data was then developed by overlap analysis. This approach yielded high resolution understory over catchment scale with a point cloud density of more than 20 points/cm<sup>2</sup>. Strong coefficients of determination (R-squared = 0.75) of the cubic model supported prediction of UVB from CHM, the average UVB was 0.82kg/m<sup>2</sup> and dominated by low ferns. The corresponding forest canopy openness in this area was 42.48% on average. Overlap analysis show no significant interactions between them in a cubic model with weak predictive power (R-squared < 0.46). Overall, we reconstructed the multi-layered structure of the forest and provided models of UVB. Understory survey has high accuracy for biomass measurement, but it’s inherently difficult to estimate UVB only based on canopy openness result.</p>


2013 ◽  
Vol 287 ◽  
pp. 17-31 ◽  
Author(s):  
Van R. Kane ◽  
James A. Lutz ◽  
Susan L. Roberts ◽  
Douglas F. Smith ◽  
Robert J. McGaughey ◽  
...  

2021 ◽  
Vol 3 (3) ◽  
pp. 330-341
Author(s):  
Andrea Karim El Meligi ◽  
◽  
Donatella Carboni ◽  
Giorgio Garau

<abstract><p>Policies concerning the sustainable tourism are fundamentally addressed to the environmental protection and to minimize the anthropogenic impact when exploiting beaches, archeological sites and other tourist attractions. In this paper, we propose a subjective measure, namely the Perceived factor, in order to take into account the more general dimension of the social factor in the assessment of the Tourism Carrying Capacity (TCC) measures. The analysis evaluates the employment impact of the perceived crowding by using data resulting from a survey conducted in the Asinara National Park. In this respect, a macroeconomic analysis is presented by using a SAM scheme developed at a local level, based on four municipalities representing a potential gravitational area of tourists visiting the Asinara National Park. Afterward, a SAM-based model combined with the sustainability measures is proposed to compute the employment loss due to the Perceived factor.</p></abstract>


2016 ◽  
Author(s):  
Rebecca K. Borchering ◽  
Steve E. Bellan ◽  
Jason M. Flynn ◽  
Juliet R.C. Pulliam ◽  
Scott A. McKinley

AbstractSubmitted Manuscript 2016. Territorial animals share a variety of common resources, which can be a major driver of conspecific encounter rates. We examine how changes in resource availability influence the rate of encounters among individuals in a consumer population by implementing a spatially explicit model for resource visitation behavior by consumers. Using data from 2009 and 2010 in Etosha National Park, we verify our model's prediction that there is a saturation effect in the expected number of jackals that visit a given carcass site as carcasses become abundant. However, this does not directly imply that the overall resource-driven encounter rate among jackals decreases. This is because the increase in available carcasses is accompanied by an increase in the number of jackals that detect and potentially visit carcasses. Using simulations and mathematical analysis of our consumer-resource interaction model, we characterize key features of the relationship between resource-driven encounter rate and model parameters. These results are used to investigate a standing hypothesis that the outbreak of a fatal disease among zebras can potentially lead to an outbreak of an entirely different disease in the jackal population, a process we refer to as indirect induction of disease.


Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3218
Author(s):  
Simon Damien Carrière ◽  
Nicolas K. Martin-StPaul ◽  
Claude Doussan ◽  
François Courbet ◽  
Hendrik Davi ◽  
...  

The spatial forest structure that drives the functioning of these ecosystems and their response to global change is closely linked to edaphic conditions. However, the latter properties are particularly difficult to characterize in forest areas developed on karst, where soil is highly rocky and heterogeneous. In this work, we investigated whether geophysics, and more specifically electromagnetic induction (EMI), can provide a better understanding of forest structure. We use EMI (EM31, Geonics Limited, Ontario, Canada) to study the spatial variability of ground properties in two different Mediterranean forests. A naturally post-fire regenerated forest composed of Aleppo pines and Holm oaks and a monospecific plantation of Altlas cedar. To better interpret EMI results, we used electrical resistivity tomography (ERT), soil depth surveys, and field observations. Vegetation was also characterized using hemispherical photographs that allowed to calculate plant area index (PAI). Our results show that the variability of ground properties contribute to explaining the variability in the vegetation cover development (plant area index). Vegetation density is higher in areas where the soil is deeper. We showed a significant correlation between edaphic conditions and tree development in the naturally regenerated forest, but this relationship is clearly weaker in the cedar plantation. We hypothesized that regular planting after subsoiling, as well as sylvicultural practices (thinning and pruning) influenced the expected relationship between vegetation structure and soil conditions measured by EMI. This work opens up new research avenues to better understand the interplay between soil and subsoil variability and forest response to climate change.


2018 ◽  
Vol 117 ◽  
pp. 50-61 ◽  
Author(s):  
Alma L. Trujillo-Miranda ◽  
Tarin Toledo-Aceves ◽  
Fabiola López-Barrera ◽  
Patricia Gerez-Fernández

PEDIATRICS ◽  
1992 ◽  
Vol 89 (6) ◽  
pp. 1173-1176
Author(s):  
Doris M. Bixby-Hammett

Using data from four sources, horse-related injuries are summarized for persons younger than 25 years of age. Head injury caused 57% of deaths. The upper extremity was the most common area injured, with the next most frequent areas the lower extremity (National Park Service data) and the head (United States Pony Clubs [USPC] data). Injured females outnumbered injured males and had a greater percentage of participants injured (USPC data). Injuries occurred at home in 41% (National Electronic Injury Surveillance System data). USPC figures suggest that greater knowledge may reduce the severity of horse-related injuries. Previous horse-related injury had occurred in 1 of 4 of those injured (USPC data). One third of accidents occurred during lessons (USPC data). Riding instructors should be certified by a recognized organization, and parents should evaluate an instructor's personal riding and their safety records with students. The pediatrician's role should be in counseling parents with children who ride and in offering recommendations for safety to governing boards of youth horse activities.


Zootaxa ◽  
2012 ◽  
Vol 3316 (1) ◽  
pp. 63 ◽  
Author(s):  
MARTIN FIKÁČEK

Georissus (Neogeorissus) smetanai sp. nov. is described from Mt. Kinabalu National Park, Sabah, Malaysia. Long series of thisspecies has been sifted from cloud forest leaf litter in contrast to most species of the genus, which are most frequently collectedin riparian zones. The species is compared with G. lateralis Delève, 1967 and G. inflatus Delève, 1972, which were collected under similar circumstances and the leaf-litter habits of the three species are briefly discussed.Keywords. Georissus, new species, leaf litter, terrestrial habitats, aptery, Malaysia, Borneo, Sri Lanka, Republic of the Congo


Sign in / Sign up

Export Citation Format

Share Document