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Full-Text Articles in Life Sciences

Geomorphology Of Tidal Wetlands: Impacts Of Extreme And Annual Flood Events To Salt Marsh And Mangrove Systems, Frances R. Griswold Apr 2023

Geomorphology Of Tidal Wetlands: Impacts Of Extreme And Annual Flood Events To Salt Marsh And Mangrove Systems, Frances R. Griswold

Doctoral Dissertations

Tidal wetlands are vital for buffering coastal settings from the threats of accelerated sea level rise and storms. Understanding the factors that are most influential for the maintenance and recovery of tidal wetlands after extreme events compounded by future accelerated sea level rise is of the utmost importance, yet this knowledge is not well established. Two tidal wetland schemas investigated in this dissertation are mangrove systems in Vieques, Puerto Rico (including robust lagoonal-mangrove forest systems and fringing mangrove forests), and salt marshes in New England. While the climatic forcings, vegetation type, and locations are vastly different for these two tidal …


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 …


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 …


On The Shoulders Of Giants: Continuing The Legacy Of Large-Scale Ecosystem Manipulation Experiments In Puerto Rico, Tana E. Wood, Grizelle González, Whendee L. Silver, Sasha C. Reed, Molly A. Cavaleri Feb 2019

On The Shoulders Of Giants: Continuing The Legacy Of Large-Scale Ecosystem Manipulation Experiments In Puerto Rico, Tana E. Wood, Grizelle González, Whendee L. Silver, Sasha C. Reed, Molly A. Cavaleri

College of Forest Resources and Environmental Science Publications

There is a long history of experimental research in the Luquillo Experimental Forest in Puerto Rico. These experiments have addressed questions about biotic thresholds, assessed why communities vary along natural gradients, and have explored forest responses to a range of both anthropogenic and non-anthropogenic disturbances. Combined, these studies cover many of the major disturbances that affect tropical forests around the world and span a wide range of topics, including the effects of forest thinning, ionizing radiation, hurricane disturbance, nitrogen deposition, drought, and global warming. These invaluable studies have greatly enhanced our understanding of tropical forest function under different disturbance regimes …


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 Feb 2017

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

Publications

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 …


Fuel Conditions Associated With Native And Exotic Grasses In A Subtropical Dry Forest In Puerto Rico, Jarrod M. Thaxton, Skip J. Van Bloem, Stefanie Whitmire Jan 2012

Fuel Conditions Associated With Native And Exotic Grasses In A Subtropical Dry Forest In Puerto Rico, Jarrod M. Thaxton, Skip J. Van Bloem, Stefanie Whitmire

Publications

Exotic grasses capable of increasing frequency and intensity of anthropogenic fire have invaded subtropical and tropical dry forests worldwide. Since many dry forest trees are susceptible to fire, this can result in decline of native species and loss of forest cover. While the contribution of exotic grasses to altered fire regimes has been well documented, the role of native grasses in contributing to fuel loads in dry forest has received little attention. We assessed differences in fuel conditions among native and exotic grasses within a subtropical dry forest preserve in Puerto Rico. We quantified fine fuel loads, fuel continuity, and …


A Link Between Hurricane-Induced Tree Sprouting, High Stem Density And Short Canopy In Tropical Dry Forest, Skip Van Bloem, Peter G. Murphy, Ariel E. Lugo Mar 2007

A Link Between Hurricane-Induced Tree Sprouting, High Stem Density And Short Canopy In Tropical Dry Forest, Skip Van Bloem, Peter G. Murphy, Ariel E. Lugo

Publications

The physiognomy of Caribbean dry forest is shorter, denser and contains a greater proportion of multi-stemmed trees than other neotropical dry forests. Our previous research, conducted after Hurricane Georges in 1998, has shown that dry forest trees sprout near the base following hurricane disturbance, even if the trees have not incurred structural damage. However, for these hurricane-induced sprouts to contribute to the physiognomy of the forest, they must grow and survive. We followed sprout dynamics and stem mortality on 1,407 stems from 1998, after Hurricane Georges, until 2005. The number of surviving sprouts and the proportion of sprouting stems decreased …


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 Jan 2006

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

Publications

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 …


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 Oct 2004

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

Publications

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 …