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Full-Text Articles in Life Sciences

Regional Forest Types - Tropical Dry Forests, Skip Van Bloem, Ariel E. Lugo, Peter G. Murphy Jul 2019

Regional Forest Types - Tropical Dry Forests, Skip Van Bloem, Ariel E. Lugo, Peter G. Murphy

Skip Van Bloem

Tropical dry forests occur in nearly every tropical country. This forest type provides critical habitat for large mammals and migratory birds, and patches of dry forest can support a high proportion of endemic plant and animal species, as well as being highly valued for agricultural and production forestry uses. Consequently, conservation and understanding of these forests need emphasis, yet conservationists and scientists still frequently overlook this ecosystem.


The Influence Of Hurricane Winds On Caribbean Dry Forest Structure And Nutrient Pools, Skip Van Bloem, Ariel E. Lugo, Rebecca Ostertag, Maria Rivera Costa, Ivelisse Ruiz Bernard, Sandra Molina Colón, Miguel Canals Mora Jul 2019

The Influence Of Hurricane Winds On Caribbean Dry Forest Structure And Nutrient Pools, Skip Van Bloem, Ariel E. Lugo, Rebecca Ostertag, Maria Rivera Costa, Ivelisse Ruiz Bernard, Sandra Molina Colón, Miguel Canals Mora

Skip Van Bloem

In 1998, we measured the effects of Hurricane Georges after it passed over long‐term research sites in Puerto Rican dry forest. Our primary objectives were to quantify hurricane effects on forest structure, to compare effects in a large tract of forest versus a series of nearby forest fragments, to evaluate short‐term response to hurricane disturbance in terms of mortality and sprouting, and to assess the ability of hurricanes to maintain forest structure. We sampled damage from 33 plots (1.3 ha) across a 3000‐ha tract of forest as well as in 19 fragments. For stems with 2.5‐cm minimum diameter, 1004 stems/ha …


Structural Response Of Caribbean Dry Forests To Hurricane Winds: A Case Study From Guanica Forest, Puerto Rico, Skip Van Bloem, Ariel E. Lugo, Peter G. Murphy Jul 2019

Structural Response Of Caribbean Dry Forests To Hurricane Winds: A Case Study From Guanica Forest, Puerto Rico, Skip Van Bloem, Ariel E. Lugo, Peter G. Murphy

Skip Van Bloem

Tropical dry forests in the Caribbean have an uniquely short, shrubby structure with a high proportion of multiple-stemmed trees compared to dry forests elsewhere in the Neotropics. Previous studies have shown that this structure can arise without the loss of main stems from cutting, grazing, or other human intervention. The Caribbean has a high frequency of hurricanes, so wind may also influence forest stature. Furthermore, these forests also tend to grow on soils with low amounts of available phosphorus, which may also influence structure. The objective of this study was to assess the role of high winds in structuring dry …


An Analysis Of Arthropod Interceptions By Aphis-Ppq And Customs And Border Protection In Puerto Rico, David A. Jenkins, Russell F. Mizell, Skip Van Bloem, Stefanie Whitmire, Leyinska Wiscovitch, Crystal Zaleski, Ricardo Goenaga Jul 2019

An Analysis Of Arthropod Interceptions By Aphis-Ppq And Customs And Border Protection In Puerto Rico, David A. Jenkins, Russell F. Mizell, Skip Van Bloem, Stefanie Whitmire, Leyinska Wiscovitch, Crystal Zaleski, Ricardo Goenaga

Skip Van Bloem

USDA Animal Plant Health Inspection Service Plant Protection and Quarantine (APHIS-PPQ) and Customs and Border Protection (CBP) inspect traffic entering the United States for arthropods posing a threat to national agriculture or ecosystems. We analyzed interceptions made by these agencies in Puerto Rico and the U.S. Virgin Islands between October 2006 and December 2009 for patterns with regard to the frequency of interceptions, origins of interceptions, and the taxa intercepted. 6,952 arthropods were intercepted in freight or luggage entering Puerto Rico and the U.S. Virgin Islands from foreign countries and 9,840 arthropods were intercepted from freight or luggage leaving Puerto …


Forest Fragments As Barriers To Fruit Fly Dispersal: Anastrepha (Diptera: Tephritidae) Populations In Orchards And Adjacent Forest Fragments In Puerto Rico, David A. Jenkins, Paul E. Kendra, Skip Van Bloem, Stefanie Whitmire, Russ Mizell Iii, Ricardo Goenaga Jul 2019

Forest Fragments As Barriers To Fruit Fly Dispersal: Anastrepha (Diptera: Tephritidae) Populations In Orchards And Adjacent Forest Fragments In Puerto Rico, David A. Jenkins, Paul E. Kendra, Skip Van Bloem, Stefanie Whitmire, Russ Mizell Iii, Ricardo Goenaga

Skip Van Bloem

McPhail-type traps baited with ammonium acetate and putrescine were used to monitor populations of Anastrepha obliqua (Macquart) and Anastrepha suspensa(Loew) in two orchards with hosts of these flies (mango, Mangifera indica L., and carambola, Averrhoa carambola L.), as well as in forest fragments bordering these orchards. Contour maps were constructed to measure population distributions in and around orchards. Our results indicate that Anastrephapopulations are focused around host fruit in both space and time, that traps do not draw fruit flies away from hosts, even when placed within 15 m of the host, and that lures continue to function …


Will Seasonally Dry Tropical Forests Be Sensitive Or Resistant To Future Changes In Rainfall Regimes?, Kara Allen, Juan Manuel Dupuy, Maria G. Gei, Catherine Hulshof, David Medvigy, Camila Pizano, Christina M. Smith, Annette Trierweiler, Skip J. Van Bloem, Bonnie G. Waring, Xiangtao Xu, Jennifer S. Powers Jul 2019

Will Seasonally Dry Tropical Forests Be Sensitive Or Resistant To Future Changes In Rainfall Regimes?, Kara Allen, Juan Manuel Dupuy, Maria G. Gei, Catherine Hulshof, David Medvigy, Camila Pizano, Christina M. Smith, Annette Trierweiler, Skip J. Van Bloem, Bonnie G. Waring, Xiangtao Xu, Jennifer S. Powers

Skip Van Bloem

Seasonally dry tropical forests (SDTF) are located in regions with alternating wet and dry seasons, with dry seasons that last several months or more. By the end of the 21st century, climate models predict substantial changes in rainfall regimes across these regions, but little is known about how individuals, species, and communities in SDTF will cope with the hotter, drier conditions predicted by climate models. In this review, we explore different rainfall scenarios that may result in ecological drought in SDTF through the lens of two alternative hypotheses: 1) these forests will be sensitive to drought because they are already …


Forecasting Effects Of Sea‐Level Rise And Windstorms On Coastal And Inland Ecosystems, Charles S. Hopkinson, Ariel E. Lugo, Merryl Alber, Alan P. Covich, Skip J. Van Bloem Jul 2019

Forecasting Effects Of Sea‐Level Rise And Windstorms On Coastal And Inland Ecosystems, Charles S. Hopkinson, Ariel E. Lugo, Merryl Alber, Alan P. Covich, Skip J. Van Bloem

Skip Van Bloem

We identify a continental‐scale network of sites to evaluate how two aspects of climate change – sea‐level rise and intensification of windstorms – will influence the structure, function, and capacity of coastal and inland forest ecosystems to deliver ecosystem services (eg carbon sequestration, storm protection, pollution control, habitat support, food). The network consists of coastal wetland and inland forest sites across the US and is representative of continental‐level gradients of precipitation, temperature, vegetation, frequency of occurrence of major windstorms, value of insured properties, tidal range, watershed land use, and sediment availability. The network would provide real‐time measurements of the characteristics …


Shifts In Biomass And Productivity For A Subtropical Dry Forest In Response To Simulated Elevated Hurricane Disturbances, Jennifer A. Holm, Skip J. Van Bloem, Guy R. Larocque, Herman H. Shugart Jul 2019

Shifts In Biomass And Productivity For A Subtropical Dry Forest In Response To Simulated Elevated Hurricane Disturbances, Jennifer A. Holm, Skip J. Van Bloem, Guy R. Larocque, Herman H. Shugart

Skip Van Bloem

Caribbean tropical forests are subject to hurricane disturbances of great variability. In addition to natural storm incongruity, climate change can alter storm formation, duration, frequency, and intensity. This model-based investigation assessed the impacts of multiple storms of different intensities and occurrence frequencies on the long-term dynamics of subtropical dry forests in Puerto Rico. Using the previously validated individual-based gap model ZELIG-TROP, we developed a new hurricane damage routine and parameterized it with site- and species-specific hurricane effects. A baseline case with the reconstructed historical hurricane regime represented the control condition. Ten treatment cases, reflecting plausible shifts in hurricane regimes, manipulated …


Multi-Temporal Unmixing Analysis Of Hyperion Images Over The Guanica Dry Forest, Maria C. Torres-Madronero, Miguel Velez-Reyes, Skip J. Van Bloem, Jesus D. Chinea Jul 2019

Multi-Temporal Unmixing Analysis Of Hyperion Images Over The Guanica Dry Forest, Maria C. Torres-Madronero, Miguel Velez-Reyes, Skip J. Van Bloem, Jesus D. Chinea

Skip Van Bloem

This paper presents a methodology to analyze time-series data from Hyperion to study seasonal vegetation dynamics on the Guánica Dry Forest in Puerto Rico. Unmixing analysis is performed over ten near-cloud-free Hyperion images collected in different months in 2008. Abundance maps and endmembers estimated from the unmixing procedure are used to analyze the seasonal changes in the forest. Results from the analysis are compared with published knowledge of the Guanica Forest phenology.