28 research outputs found
Ecological interactions of the cadmium- and zinc-hyperaccumulating plant, Thlaspi caerulescens, and their implications for phytoremediation
The success of invasive species can be attributed to a combination of abiotic factors, such as abundant resources and favorable climate, and biotic factors, such as low levels of competition and predation or herbivory, at the introduced location. While studies have demonstrated the effects of these factors on known invasive species, the degree to which these factors affect a non-native species can be used to predict its likelihood of becoming invasive. The metal-hyperaccumulating plant Thlaspi caerulescens (Brassicaceae) is potentially useful for remediating soils that are moderately contaminated with Cd and Zn, and has been experimentally introduced to contaminated sites outside of its native range for phytoremediation. To assess the ecological risks involved in introducing metal-hyperaccumulating plants for phytoremediation, including their potential invasiveness, I have performed three studies to examine the abiotic and biotic factors that could influence the establishment of T. caerulescens at three contaminated sites near the Rocky Mountain Biological Laboratory in Gothic, Colorado. In the first two studies, I test the effects of soil metal concentrations and interspecific competition on plant performance, and in the third study I examine the strength of herbivore pressure on this plant. Results from these studies show that the growth rate of T. caerulescens in field conditions is generally low, but higher where there are high concentrations of soil Zn and low concentrations of soil Cu. Interspecific competition between T. caerulescens and a native congener is weak overall, and herbivory pressure from a native Lepidopteran herbivore is also low. Therefore, abiotic conditions are more limiting to T. caerulescens than biotic interactions, and would likely prevent T. caerulescens from becoming invasive or spreading outside of contaminated soils at these sites. In the fourth chapter, I use a long-term dataset to describe the demography of Frasera speciosa (Gentianaceae), a long-lived monocarpic plant. Results show that the population is stable, and despite the low elasticity values for the reproductive stages, masting events must be observed to describe accurately the population dynamics of this species
The Blind Spot in the Green Revolution: Temples, Terraces, and Rice Farmers of Bali
This is a teaching case study based on the anthropological research of Dr. Steven Lansing, and part of the SESYNC collection of socio-environmental case studies (www.sesync.org)This case explores the complex interactions in a socio-environmental system, the Balinese wet rice cultivation system. Using a combination of the interrupted case and directed case methods, students are presented with an issue that arose during the implementation of Green Revolution agricultural policies in Bali: rice farmers were required to plant new high yield rice varieties continuously rather than following the coordinated cropping schedules set up by water temple priests. Students examine qualitative and quantitative data from classic anthropological research by Dr. Steven Lansing to learn about the important role that water temples play in achieving sustainable rice cultivation in Bali. Using a model that synthesizes ecological, hydrological, and ethnographic data, Lansing and his colleague, Dr. James Kremer, were able to demonstrate that temple priests determine the cropping schedules for farmers in a way that reduces pest growth and helps to manage limited water resources, maximizing rice yields. This four-part case can be used for a wide range of courses in a few class periods (total class time approximately 4.5-5 hrs.)This work was supported by the University of Maryland and NSF Award # DBI-1052875 to the National Socio-Environmental Synthesis Center (SESYNC
Save the Turtles! And the Grizzlies? Or the Woodpeckers? Prioritizing Endangered Species Conservation
This is a teaching resource developed to teach about socio-environmental synthesis. Specifically, it is a case study teaching activity focused on endangered species conservation.This case study explores the complexities involved in endangered species management and provides an opportunity for students to perform an exercise in socio-environmental synthesis. Developed for introductory undergraduate courses in environmental studies or conservation biology, it contains suggested modifications for upper-level undergraduate and graduate courses. Students take the position of wildlife managers who must decide how best to allocate limited resources for conserving multiple threatened and endangered species. Students are provided with data on the ecological characteristics and socio-economic circumstances for a set of five species, and then work in small groups to develop conservation priority rankings based on those data. Students summarize their decisions in writing and in small-group presentations, and the case concludes with an instructor-led discussion of how actual conservation priorities are determined.NSF Award # DBI-1052875 to the National Socio-Environmental Synthesis Cente
The call of the emperor penguin: Legal responses to species threatened by climate change
Species extinction risk is accelerating due to anthropogenic climate change, making it urgent to protect vulnerable species through legal frameworks in order to facilitate conservation actions that help mitigate risk. Here, we discuss fundamental concepts for assessing climate change risks to species using the example of the emperor penguin (Aptenodytes forsteri), currently being considered for protection under the US Endangered Species Act (ESA). This species forms colonies on Antarctic sea ice, which is projected to significantly decline due to ongoing greenhouse gas (GHG) emissions. We project the dynamics of all known emperor penguin colonies under different GHG emission scenarios using a climate-dependent meta-population model including the effects of extreme climate events based on the observational satellite record of colonies. Assessments for listing species under the ESA require information about how species resiliency, redundancy and representation (3Rs) will be affected by threats within the foreseeable future. Our results show that if sea ice declines at the rate projected by climate models under current energy system trends and policies, the 3Rs would be dramatically reduced and almost all colonies would become quasi-extinct by 2100. We conclude that the species should be listed as threatened under the ESA
Comments to âPersistent problems in the construction of matrix population modelsâ
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A standard protocol to report discrete stage-structured demographic information
Stage-based demographic methods, such as matrix population models (MPMs), are powerful tools used to address a broad range of fundamental questions in ecology, evolutionary biology and conservation science. Accordingly, MPMs now exist for over 3000 species worldwide. These data are being digitised as an ongoing process and periodically released into two large open-access online repositories: the COMPADRE Plant Matrix Database and the COMADRE Animal Matrix Database. During the last decade, data archiving and curation of COMPADRE and COMADRE, and subsequent comparative research, have revealed pronounced variation in how MPMs are parameterized and reported.
Here, we summarise current issues related to the parameterisation and reporting of MPMs that arise most frequently and outline how they affect MPM construction, analysis, and interpretation. To quantify variation in how MPMs are reported, we present results from a survey identifying key aspects of MPMs that are frequently unreported in manuscripts. We then screen COMPADRE and COMADRE to quantify how often key pieces of information are omitted from manuscripts using MPMs.
Over 80% of surveyed researchers (n = 60) state a clear benefit to adopting more standardised methodologies for reporting MPMs. Furthermore, over 85% of the 300 MPMs assessed from COMPADRE and COMADRE omitted one or more elements that are key to their accurate interpretation. Based on these insights, we identify fundamental issues that can arise from MPM construction and communication and provide suggestions to improve clarity, reproducibility and future research utilising MPMs and their required metadata. To fortify reproducibility and empower researchers to take full advantage of their demographic data, we introduce a standardised protocol to present MPMs in publications. This standard is linked to www.compa dre-db.org, so that authors wishing to archive their MPMs can do so prior to submission of publications, following examples from other open-access repositories such as DRYAD, Figshare and Zenodo.
Combining and standardising MPMs parameterized from populations around the globe and across the tree of life opens up powerful research opportunities in evolutionary biology, ecology and conservation research. However, this potential can only be fully realised by adopting standardised methods to ensure reproducibility
A standard protocol to report discrete stage-structured demographic information
Stage-based demographic methods, such as matrix population models (MPMs), are powerful tools used to address a broad range of fundamental questions in ecology, evolutionary biology and conservation science. Accordingly, MPMs now exist for over 3000 species worldwide. These data are being digitised as an ongoing process and periodically released into two large open-access online repositories: the COMPADRE Plant Matrix Database and the COMADRE Animal Matrix Database. During the last decade, data archiving and curation of COMPADRE and COMADRE, and subsequent comparative research, have revealed pronounced variation in how MPMs are parameterized and reported.
Here, we summarise current issues related to the parameterisation and reporting of MPMs that arise most frequently and outline how they affect MPM construction, analysis, and interpretation. To quantify variation in how MPMs are reported, we present results from a survey identifying key aspects of MPMs that are frequently unreported in manuscripts. We then screen COMPADRE and COMADRE to quantify how often key pieces of information are omitted from manuscripts using MPMs.
Over 80% of surveyed researchers (nâ=â60) state a clear benefit to adopting more standardised methodologies for reporting MPMs. Furthermore, over 85% of the 300 MPMs assessed from COMPADRE and COMADRE omitted one or more elements that are key to their accurate interpretation. Based on these insights, we identify fundamental issues that can arise from MPM construction and communication and provide suggestions to improve clarity, reproducibility and future research utilising MPMs and their required metadata. To fortify reproducibility and empower researchers to take full advantage of their demographic data, we introduce a standardised protocol to present MPMs in publications. This standard is linked to www.compadre-db.org, so that authors wishing to archive their MPMs can do so prior to submission of publications, following examples from other open-access repositories such as DRYAD, Figshare and Zenodo.
Combining and standardising MPMs parameterized from populations around the globe and across the tree of life opens up powerful research opportunities in evolutionary biology, ecology and conservation research. However, this potential can only be fully realised by adopting standardised methods to ensure reproducibility
Population matrix models for Frasera speciosa from 1974 to 2007
Each matrix contains the probability of going from a stage (the column headings) to another stage (the rows) from the starting year (given as the heading of the matrix) to the following year for individuals in the Frasera speciosa population. There are two dormant seed categories, a recruit or seedling category, and twelve leaf-number stages: 2 (1-2 leaves), 4 (3-4 leaves), 6 (5-6 leaves), 9 (7-10 leaves), 12 (11-14 leaves), 16 (15-17 leaves), 20 (18-22 leaves), 25 (23-27 leaves), 30 (28-32 leaves), 36 (33-38 leaves), 42 (39-45 leaves), or 49 (46-64 leaves).This file contains the matrix population models for a population of Frasera speciosa in the Elk Mountains of southwestern Colorado, for the years 1974-2007