We discuss the benefits that a collaborative research network, a group of faculty from different ... more We discuss the benefits that a collaborative research network, a group of faculty from different institutions who jointly conduct a research project, can have on undergraduate research (UR) by enhancing the diversity and significance of projects and by improving student motivation and breadth of learning. The main example used is the Ecological Research as Education Network (EREN), founded in 2010 to enhance undergraduate research in ecology at primarily undergraduate institutions (PUIs) by (1) providing networking and collaborative research opportunities for both faculty and students and (2) developing free educational resources. EREN comprises about 280 ecology faculty and staff nationally and has facilitated development of nine continental-scale, collaborative research projects.
With the increase in urban development, forest fragments are becoming more prevalent. In urban ar... more With the increase in urban development, forest fragments are becoming more prevalent. In urban areas, there is a tendency to hide power-lines within or on the edges of these fragmented forests; however, it is unknown how the maintenance of vegetation under and along ...
Page 1. 184 In the northeastern United States and southeastern Canada, the Deer Mouse, Peromyscus... more Page 1. 184 In the northeastern United States and southeastern Canada, the Deer Mouse, Peromyscus maniculatus, and the White-footed Mouse, Peromyscus leucopus, are sympatric over a large portion of their ranges (Klein ...
ABSTRACT Background/Question/Methods Freshwater turtle populations can be profoundly impacted by ... more ABSTRACT Background/Question/Methods Freshwater turtle populations can be profoundly impacted by urbanization. Adult females may experience high mortality with increased road density near nesting sites, leading to a male-biased population. Juvenile recruitment can be reduced by the high density of predators that often exist in human-dominated landscapes, resulting in an adult-biased population. To determine if the population structure of freshwater turtles follows these patterns at widespread sites with varying degrees of urbanization, over 30 faculty and their students at 26 institutions extending from Massachusetts to Oklahoma conducted a mark-recapture study of turtles inhabiting lentic ecosystems. The research was conceived, organized, and operated through the Ecological Research as Education Network (EREN, www.erenweb.org). EREN facilitates research and collaboration among students and faculty at primarily undergraduate institutions. Between August and early October 2012, each participant placed a minimum of four hoop traps in each of their respective ponds for at least two consecutive days and marked, measured, and released any captured turtles. We sampled a total of 39 ponds. For each pond with a minimum of ten individuals per species, we used chi-square goodness-of-fit tests to analyze whether the adult sex ratio differed from parity and the juvenile:adult ratio differed from 1:5 for each species. Results/Conclusions We caught the painted turtle (Chrysemys picta), pond slider (Trachemys scripta), common snapping turtle (Chelydra serpentina), common musk turtle (Sternotherus odoratus), smooth softshell (Apalone mutica), and common map turtle (Graptemys geographica) across 34 ponds. Turtles were not caught in the other five ponds. Only the painted turtle was caught in sufficient numbers per pond to permit the statistical analysis of age-sex class ratio. It was detected in 29 of the ponds, with 16 ponds yielding captures of at least ten individuals. The adult sex ratio was significantly biased towards adult males in eight ponds and did not differ from parity in the remaining eight ponds. A significant deviation from expectation for the juvenile:adult ratio was detected in six of the 16 ponds. Significantly more juveniles than expected were caught in three ponds and fewer juveniles in the other three ponds. Faculty and students will continue the turtle sampling in fall 2013 and will characterize urbanization by measuring landscape attributes around each sampled pond. As the research continues, we will be able to assess more thoroughly how the population structure of freshwater turtles varies with urbanization across much of North America.
ABSTRACT Background/Question/Methods The Ecological Research as Education Network (EREN) Permanen... more ABSTRACT Background/Question/Methods The Ecological Research as Education Network (EREN) Permanent Forest Plot Project (PFPP) has been developed within the EREN collaborative research model of generating high-quality, publishable ecological data with undergraduate students and faculty at primarily undergraduate institutions. The specific goals of PFPP are to develop protocols for the installation and multi-year monitoring of 20 x 20 m permanent forest plots across multiple landscapes and regions, and to generate long term tree and forest site datasets stored in a searchable, online database available for teaching and/or research. Some of the key ecological questions that can be addressed with these data include 1) biomass/carbon storage potential in forests of different ages, types, or levels of disturbance (e.g.interior vs edge; presence vs absence of invasive species), 2) annual rates of woody biomass and carbon accumulation in relation to temperature, precipitation, nutrient levels, or other environmental variables, and 3) diversity, density, size class frequency, phenology, soil chemistry, soil macroinvertebrate, and understory plant comparisons across landscapes and regions. For this approach to be successful 1) the protocols must work within the constraints of scientists with significant teaching responsibilities, and 2) quality assurance/quality control techniques must be established to ensure that the data collected and reported by undergraduates is of the highest quality. The protocols were developed and tested over multiple sites for two years before the database, specifically designed for PFPP, went online in 2012. Data management practices include incorporating site and plot specific metadata into the archived database. Results/Conclusions As of Feb 2014, there are 130 registered users (30% students) from 48 institutions. The database contains 92 different plots, representing 21 sites. Tree data have been uploaded for 86 plots, and multiple year measurements are available for 12. Additional data have been collected, but not uploaded, due to faculty concerns about data quality. A test of measurement precision conducted at two EREN institutions revealed that absolute mean differences in repeated dbh measurements made by student researchers ranged from 0.18 to 0.26 cm. Even with this variability, however, PFPP data have been used successfully to compare carbon sequestration in restored and mature maple-basswood forests in Minnesota, with the restored site showing a threefold increase in carbon sequestration over that of the mature forest. Data quality remains a PFPP priority, and we are continuing to develop QA/QC procedures, which are posted on the EREN PFPP curriculum webpage.
Recently, the importance of seed predation by crabs on mangrove species distributions and densiti... more Recently, the importance of seed predation by crabs on mangrove species distributions and densities has been established by several studies. In a tropical coastal terrestrial forest in Costa Rica, we investigated the relative importance of predation by land crabs, Gecarcinus quadratus, and hermit crabs, Coenobita compressus, on measured forest composition through a series of seed removal and seedling establishment experiments. We also used natural light-gaps and adjacent non-gap sites to test how canopy cover affects crab predation (seed removal) and seedling establishment. We found fewer tree species (S=18) and lower densities (seedlings, saplings, and adults) in the coastal zone within 100 m of coastline, than in the inland zone (S=59). Land crab densities were higher in the coastal zone (3.03±1.44 crabs m −2 ) than in the inland zone (0.76±0.78 crabs m −2 ), and hermit crabs were not present in the inland zone. Seed removal and seedling mortality also were higher in the coastal zone than in the inland zone, and in the open controls than in the crab exclosures. Mortality of seeds and seedlings was two to six times higher in the controls than exclosures for four of the five experiments. Crabs preferred seeds and younger seedlings over older seedlings but showed no species preferences in the seed (Anacardium excelsum, Enterolobium cyclocarpum, and Terminalia oblonga) and seedling (Pachira quinata and E. cyclocarpum) stages. We conclude that the observed differences in tree densities were caused by differential crab predation pressure along the coastal gradient, while the differences in species composition were due to predator escape (satiation) by seed quantity. Canopy cover did not affect seed removal rates, but did affect seedling survival with higher mortality in the non-gap versus gap environments. In summary, crab predation of seeds and seedlings, and secondarily canopy cover, are important factors affecting tree establishment in terrestrial coastal forests.
Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influe... more Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influence seed dispersal and viability, and seedling establishment and growth at the microsite. Rarely does one animal guild exert as significant an influence on different plant assemblages as land crabs. We review three tropical coastal ecosystemsmangroves, island maritime forests, and mainland coastal terrestrial forests-where land crabs directly influence forest composition by limiting tree establishment and recruitment. Land crabs differentially prey on seeds, propagules and seedlings along nutrient, chemical and physical environmental gradients. In all of these ecosystems, but especially mangroves, abiotic gradients are well studied, strong and influence plant species distributions. However, we suggest that crab predation has primacy over many of these environmental factors by acting as the first limiting factor of tropical tree recruitment to drive the potential structural and compositional organisation of coastal forests. We show that the influence of crabs varies relative to tidal gradient, shoreline distance, canopy position, time, season, tree species and fruiting periodicity. Crabs also facilitate forest growth and development through such activities as excavation of burrows, creation of soil mounds, aeration of soils, removal of leaf litter into burrows and creation of carbon-rich soil microhabitats. For all three systems, land crabs influence the distribution, density and size-class structure of tree populations. Indeed, crabs are among the major drivers of tree recruitment in tropical coastal forest ecosystems, and their conservation should be included in management plans of these forests.
We discuss the benefits that a collaborative research network, a group of faculty from different ... more We discuss the benefits that a collaborative research network, a group of faculty from different institutions who jointly conduct a research project, can have on undergraduate research (UR) by enhancing the diversity and significance of projects and by improving student motivation and breadth of learning. The main example used is the Ecological Research as Education Network (EREN), founded in 2010 to enhance undergraduate research in ecology at primarily undergraduate institutions (PUIs) by (1) providing networking and collaborative research opportunities for both faculty and students and (2) developing free educational resources. EREN comprises about 280 ecology faculty and staff nationally and has facilitated development of nine continental-scale, collaborative research projects.
With the increase in urban development, forest fragments are becoming more prevalent. In urban ar... more With the increase in urban development, forest fragments are becoming more prevalent. In urban areas, there is a tendency to hide power-lines within or on the edges of these fragmented forests; however, it is unknown how the maintenance of vegetation under and along ...
Page 1. 184 In the northeastern United States and southeastern Canada, the Deer Mouse, Peromyscus... more Page 1. 184 In the northeastern United States and southeastern Canada, the Deer Mouse, Peromyscus maniculatus, and the White-footed Mouse, Peromyscus leucopus, are sympatric over a large portion of their ranges (Klein ...
ABSTRACT Background/Question/Methods Freshwater turtle populations can be profoundly impacted by ... more ABSTRACT Background/Question/Methods Freshwater turtle populations can be profoundly impacted by urbanization. Adult females may experience high mortality with increased road density near nesting sites, leading to a male-biased population. Juvenile recruitment can be reduced by the high density of predators that often exist in human-dominated landscapes, resulting in an adult-biased population. To determine if the population structure of freshwater turtles follows these patterns at widespread sites with varying degrees of urbanization, over 30 faculty and their students at 26 institutions extending from Massachusetts to Oklahoma conducted a mark-recapture study of turtles inhabiting lentic ecosystems. The research was conceived, organized, and operated through the Ecological Research as Education Network (EREN, www.erenweb.org). EREN facilitates research and collaboration among students and faculty at primarily undergraduate institutions. Between August and early October 2012, each participant placed a minimum of four hoop traps in each of their respective ponds for at least two consecutive days and marked, measured, and released any captured turtles. We sampled a total of 39 ponds. For each pond with a minimum of ten individuals per species, we used chi-square goodness-of-fit tests to analyze whether the adult sex ratio differed from parity and the juvenile:adult ratio differed from 1:5 for each species. Results/Conclusions We caught the painted turtle (Chrysemys picta), pond slider (Trachemys scripta), common snapping turtle (Chelydra serpentina), common musk turtle (Sternotherus odoratus), smooth softshell (Apalone mutica), and common map turtle (Graptemys geographica) across 34 ponds. Turtles were not caught in the other five ponds. Only the painted turtle was caught in sufficient numbers per pond to permit the statistical analysis of age-sex class ratio. It was detected in 29 of the ponds, with 16 ponds yielding captures of at least ten individuals. The adult sex ratio was significantly biased towards adult males in eight ponds and did not differ from parity in the remaining eight ponds. A significant deviation from expectation for the juvenile:adult ratio was detected in six of the 16 ponds. Significantly more juveniles than expected were caught in three ponds and fewer juveniles in the other three ponds. Faculty and students will continue the turtle sampling in fall 2013 and will characterize urbanization by measuring landscape attributes around each sampled pond. As the research continues, we will be able to assess more thoroughly how the population structure of freshwater turtles varies with urbanization across much of North America.
ABSTRACT Background/Question/Methods The Ecological Research as Education Network (EREN) Permanen... more ABSTRACT Background/Question/Methods The Ecological Research as Education Network (EREN) Permanent Forest Plot Project (PFPP) has been developed within the EREN collaborative research model of generating high-quality, publishable ecological data with undergraduate students and faculty at primarily undergraduate institutions. The specific goals of PFPP are to develop protocols for the installation and multi-year monitoring of 20 x 20 m permanent forest plots across multiple landscapes and regions, and to generate long term tree and forest site datasets stored in a searchable, online database available for teaching and/or research. Some of the key ecological questions that can be addressed with these data include 1) biomass/carbon storage potential in forests of different ages, types, or levels of disturbance (e.g.interior vs edge; presence vs absence of invasive species), 2) annual rates of woody biomass and carbon accumulation in relation to temperature, precipitation, nutrient levels, or other environmental variables, and 3) diversity, density, size class frequency, phenology, soil chemistry, soil macroinvertebrate, and understory plant comparisons across landscapes and regions. For this approach to be successful 1) the protocols must work within the constraints of scientists with significant teaching responsibilities, and 2) quality assurance/quality control techniques must be established to ensure that the data collected and reported by undergraduates is of the highest quality. The protocols were developed and tested over multiple sites for two years before the database, specifically designed for PFPP, went online in 2012. Data management practices include incorporating site and plot specific metadata into the archived database. Results/Conclusions As of Feb 2014, there are 130 registered users (30% students) from 48 institutions. The database contains 92 different plots, representing 21 sites. Tree data have been uploaded for 86 plots, and multiple year measurements are available for 12. Additional data have been collected, but not uploaded, due to faculty concerns about data quality. A test of measurement precision conducted at two EREN institutions revealed that absolute mean differences in repeated dbh measurements made by student researchers ranged from 0.18 to 0.26 cm. Even with this variability, however, PFPP data have been used successfully to compare carbon sequestration in restored and mature maple-basswood forests in Minnesota, with the restored site showing a threefold increase in carbon sequestration over that of the mature forest. Data quality remains a PFPP priority, and we are continuing to develop QA/QC procedures, which are posted on the EREN PFPP curriculum webpage.
Recently, the importance of seed predation by crabs on mangrove species distributions and densiti... more Recently, the importance of seed predation by crabs on mangrove species distributions and densities has been established by several studies. In a tropical coastal terrestrial forest in Costa Rica, we investigated the relative importance of predation by land crabs, Gecarcinus quadratus, and hermit crabs, Coenobita compressus, on measured forest composition through a series of seed removal and seedling establishment experiments. We also used natural light-gaps and adjacent non-gap sites to test how canopy cover affects crab predation (seed removal) and seedling establishment. We found fewer tree species (S=18) and lower densities (seedlings, saplings, and adults) in the coastal zone within 100 m of coastline, than in the inland zone (S=59). Land crab densities were higher in the coastal zone (3.03±1.44 crabs m −2 ) than in the inland zone (0.76±0.78 crabs m −2 ), and hermit crabs were not present in the inland zone. Seed removal and seedling mortality also were higher in the coastal zone than in the inland zone, and in the open controls than in the crab exclosures. Mortality of seeds and seedlings was two to six times higher in the controls than exclosures for four of the five experiments. Crabs preferred seeds and younger seedlings over older seedlings but showed no species preferences in the seed (Anacardium excelsum, Enterolobium cyclocarpum, and Terminalia oblonga) and seedling (Pachira quinata and E. cyclocarpum) stages. We conclude that the observed differences in tree densities were caused by differential crab predation pressure along the coastal gradient, while the differences in species composition were due to predator escape (satiation) by seed quantity. Canopy cover did not affect seed removal rates, but did affect seedling survival with higher mortality in the non-gap versus gap environments. In summary, crab predation of seeds and seedlings, and secondarily canopy cover, are important factors affecting tree establishment in terrestrial coastal forests.
Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influe... more Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influence seed dispersal and viability, and seedling establishment and growth at the microsite. Rarely does one animal guild exert as significant an influence on different plant assemblages as land crabs. We review three tropical coastal ecosystemsmangroves, island maritime forests, and mainland coastal terrestrial forests-where land crabs directly influence forest composition by limiting tree establishment and recruitment. Land crabs differentially prey on seeds, propagules and seedlings along nutrient, chemical and physical environmental gradients. In all of these ecosystems, but especially mangroves, abiotic gradients are well studied, strong and influence plant species distributions. However, we suggest that crab predation has primacy over many of these environmental factors by acting as the first limiting factor of tropical tree recruitment to drive the potential structural and compositional organisation of coastal forests. We show that the influence of crabs varies relative to tidal gradient, shoreline distance, canopy position, time, season, tree species and fruiting periodicity. Crabs also facilitate forest growth and development through such activities as excavation of burrows, creation of soil mounds, aeration of soils, removal of leaf litter into burrows and creation of carbon-rich soil microhabitats. For all three systems, land crabs influence the distribution, density and size-class structure of tree populations. Indeed, crabs are among the major drivers of tree recruitment in tropical coastal forest ecosystems, and their conservation should be included in management plans of these forests.
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