Sarah Bois - Academia.edu (original) (raw)
Papers by Sarah Bois
Journal of Applied Ecology, 2009
Summary 1. To ensure the successful detection, control and eradication of invasive plant species,... more Summary 1. To ensure the successful detection, control and eradication of invasive plant species, we need information that can identify areas prone to invasions and criteria that can point out which particular populations may become foci of further spread. Specifically, our work aimed to develop statistical models that identify hotspots of invasive plant species and evaluate the conditions that give rise to successful populations of invasive species. 2. We combined extensive data sets on invasive species richness and on species per cent ground cover, together with climate, local habitat and land cover data. We then estimated invasive species richness as a function of those environmental variables by developing a spatially explicit generalized linear model within a hierarchical Bayesian framework. In a second analysis, we used an ordinal logistic regression model to quantify invasive species abundance as a function of the same set of predictor variables. 3. Our results show which loc...
Bookmarks Related papers MentionsView impact
Restoration Ecology
A high proportion of regional plant biodiversity occurs in hotspots of species richness that cove... more A high proportion of regional plant biodiversity occurs in hotspots of species richness that cover small areas created and maintained by disturbance. Sustaining plant diversity in these areas requires region‐ and habitat‐specific management of disturbance and, increasingly, habitat expansion or restoration to offset species losses. Coastal sandplain grasslands are threatened, disturbance‐controlled plant biodiversity hotspots in the northeastern United States. We formed a network of grassland managers and scientists to review the published and unpublished sandplain grassland literature. Additionally, we conducted interviews with grassland managers about management challenges and successes. Principal concerns of managers were increases in woody plant cover, losses of rare species, increased cover and variety of invasive species, and constraints on the ability to use prescribed fire. The literature review and managers' experiences together led to the following recommendations: (1)...
Bookmarks Related papers MentionsView impact
Plant Ecology, 2015
Bookmarks Related papers MentionsView impact
Rhodora, 2017
Bookmarks Related papers MentionsView impact
BioScience, 2011
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Proceedings of the National Academy of Sciences
Forecasting ecological responses to climate change, invasion, and their interaction must rely on ... more Forecasting ecological responses to climate change, invasion, and their interaction must rely on understanding underlying mechanisms. However, such forecasts require extrapolation into new locations and environments. We linked demography and environment using experimental biogeography to forecast invasive and native species’ potential ranges under present and future climate in New England, United States to overcome issues of extrapolation in novel environments. We studied two potentially nonequilibrium invasive plants’ distributions, Alliaria petiolata (garlic mustard) and Berberis thunbergii (Japanese barberry), each paired with their native ecological analogs to better understand demographic drivers of invasions. Our models predict that climate change will considerably reduce establishment of a currently prolific invader (A. petiolata) throughout New England driven by poor demographic performance in warmer climates. In contrast, invasion of B. thunbergii will be facilitated becaus...
Bookmarks Related papers MentionsView impact
Rhodora
There is nothing so wonderful as a botanical foray to a new area. Your pack may have a water bott... more There is nothing so wonderful as a botanical foray to a new area. Your pack may have a water bottle, a hand lens, a field notebook (a vasculum if you were Les Mehrhoff), and perhaps a small press. What about a field guide? In New England, which current tome or doggedear guide from decades past would you toss into your pack? The new Wildflowers of New England may be just that field guide. Ted Elliman’s Wildflowers of New England is a field guide of the classic Peterson’s format covering over 1100 forbs and small flowering shrubs of the region. In my tenure as a field biologist/plant ecologist, I have longed for a regional field guide such as this; New England-centric with current taxonomic information, color pictures, and easy-to-use keys. This is both for my own use as well as a guide to recommend to newcomers to New England, budding botanists, interns, and students interested in New England botany at any level. This is the first field guide I have seen from any region that bridges the gaps between on-line databases/flora and systematic keys. Being a compendium of sorts to the 2011 Flora Novae Angliae as well as the popular Go Botany on-line key, Wildflowers of New England serves its purpose well as an easy-to-use hands-on guide with accurate information for the most likely plants. Author Ted Elliman uses his vast knowledge of the flora of the New England region to detail telltale characteristics of the New England flora. Ted Elliman, staff botanist at the New England Wildflower Society, has decades of experience all across New England. He is a thoughtful, careful botanist and conservationist. The New England Wildflower Society, and Ted himself, have made significant contributions to the conservation of species and habitats in New England. This field guide is a testament to that work and to NEWFS’ continued mission to educate the public about plant conservation in the region. When I first got my copy, I was immediately swayed by having one of my favorite spring wildflowers on the cover. Commonly called Quaker-ladies where I live on Nantucket Island, Houstonia caerulea (a.k.a. bluets) graces the front cover. The wonderful macro photogra-
Bookmarks Related papers MentionsView impact
Rhodora, 2015
The consequences of initial variability in reproductive effort on later pollination and fruit dev... more The consequences of initial variability in reproductive effort on later pollination and fruit development have frequently been investigated with flower removal experiments. Often, plants produce many fewer fruits than flowers, so flower removal might not be expected to alter subsequent growth or development patterns all that much. Yet, many studies have demonstrated such changes even for species with low average fruit set, which begs for an explanation. Many (at least seven, by our count) such explanations have been reported in the literature, but experimental support for most is limited. In summer 2014, we conducted a field experiment on a lowbush blueberry (Vaccinium angustifolium) farm in Maine. In this experiment, we coupled flower removal with three other treatments, each designed to assess the validity of one of three often-cited hypotheses invoked to explain why growth and development changes occur following flower removal: 1) “Short-term nutrient shortages;” 2) “spatiotemporal limitations;” and 3) “the compound interest effect.” The three respective treatments—foliar nitrogen fertilization, positionally biased flower removal, and defoliation—were designed to either intensify or weaken the apparent effects of flower removal if the corresponding hypothesis had merit. As in a 2013 preliminary experiment, flower removal elicited several statistically significant growth and development changes in blueberry, including increases in final leaf area, ripe fruit weight, fruit ripening rate, and relative fruit production. The additional treatments also elicited several significant plant responses, though not always with concomitant flower removal effects as well. For example, fertilization generally increased fruit cluster mass by harvest, but flower removal itself had no such effect on cluster mass. Most observed interactive effects between flower removal and the additional treatments either ran counter to expectations, were limited in scope, or couldn't be unambiguously interpreted. For at least a few observed changes, none of the additional treatments significantly altered the effects of flower removal. We conclude that current hypotheses for the mechanistic basis for changes induced by flower removal are inadequate, at least for blueberry, a species with frequently low fruit set even when managed commercially. However, strong intellectual and economic imperatives exist to encourage further investigation into this open question.Plants grown in horticulture or occurring as adventives outside their native range can provide insight into species’ fundamental niche requirements that might not be evident from the native range, or realized niche, alone. Such occurrences can also identify conditions that support individual survival, but do not currently sustain positive population growth (i.e., a species’ ‘tolerance niche’). Further, in the context of rapid climate change, horticultural and adventive occurrences beyond current range edges might circumvent natural dispersal limitations and facilitate species range shifts. To explore these concepts in the field, we investigated the history and structure of five newly discovered populations of naturalized Magnolia tripetala near horticultural sites in western Massachusetts, USA. This tree species is native to the southeastern US, but has been grown horticulturally in the Northeast since the 1800s. However, naturalized populations had not been well documented in the region previously, raising the possibility that the species’ escape has been triggered by recent climate change. With tree coring and life stage surveys, we asked whether the naturalized populations exhibited synchronous patterns of establishment and expansion, suggestive of climatic release and a shift from tolerance niche to fundamental niche conditions in the region. Across the five sites, we documented 660 individuals, with populations ranging in size from 46 to 396 individuals, including seedlings, saplings, and reproduct
Bookmarks Related papers MentionsView impact
Background/Question/Methods As part of a multi-scale project to predict invasive plant spread in ... more Background/Question/Methods As part of a multi-scale project to predict invasive plant spread in response to climate and land-use change, we are evaluating the environmental conditions that facilitate the establishment of three invasive alien species (IAS) in New England. Previously developed predictive models have highlighted areas of northern New England currently lacking IAS as places where these species may potentially thrive. As these IAS move northward, they will encounter novel conditions affecting establishment and growth. How these species respond will influence their further spread and impact across the region. We established a regional transplant experiment to test predictive model results and to estimate the colonization potential for three common IAS in New England: Berberis thunbergii, Celastrus orbiculatus, and Alliaria petiolata. Native analogs to each of these species were selected to quantify response differences; Lindera benzoin, Vitis labrusca, and Arabis glabra....
Bookmarks Related papers MentionsView impact
Background/Question/Methods Invasive species’ geographic distributions are often not at equilibri... more Background/Question/Methods Invasive species’ geographic distributions are often not at equilibrium in their invasive ranges. Therefore, invasion risk based on current occurrence patterns may lead to biased estimates of the locations at risk of invasion. We took an experimental biogeographical approach to investigating the underlying demographic processes that drive population dynamics across a range of potentially invasible environmental conditions. By linking demographic rates (growth, survival, fecundity) to explanatory environmental variables we obtained a mechanistic basis for determining species range limits. These mechanisms are particularly important for understanding invasive species distributions to improve early detection abilities for species with nonequilibrium distributions. We investigated population dynamics of two invasive species: a monocarpic biennial (Alliaria petiolata; garlic mustard) and a woody shrub (Berberis thunbergii; Japanese barberry) and two native eco...
Bookmarks Related papers MentionsView impact
Background/Question/Methods Knowledge of a species' range limit is important when triaging fo... more Background/Question/Methods Knowledge of a species' range limit is important when triaging for non-native invasive species management. With invasive species, we often have limited data at the early stages of invasion as species are not at equilibrium. These species may be beyond eradication or control by the time enough demographic data are collected. Inferring population dynamics based on current locations of invasive populations may under- or over-estimate population growth rates and, thus, potential spread. Understanding how environmental variation affects demographic parameters is important in determining species range limits and to providing a mechanistic basis for understanding invasions. Mechanistic models increase our confidence when extrapolating population level patterns to a new set of conditions or novel landscape. We investigated establishment dynamics of two non-native invasive species; the woody Berberis thunbergii and the monocarpic biennial Alliaria petiolata, a...
Bookmarks Related papers MentionsView impact
Phenotypic plasticity may be an important contributor to the success of many invasive plant speci... more Phenotypic plasticity may be an important contributor to the success of many invasive plant species. Shifts in genotype induced by the recipient environment can also lead to a range of phenotypic expression not seen in the native range. Selection for these novel genotypes could lead to local adaptation in the introduced environment. To investigate plasticity and local adaptation in an invaded region, we established three reciprocal transplant gardens using clonal replicates from two common invasive species in New England, Berberis ...
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Journal of Applied Ecology, 2009
Summary 1. To ensure the successful detection, control and eradication of invasive plant species,... more Summary 1. To ensure the successful detection, control and eradication of invasive plant species, we need information that can identify areas prone to invasions and criteria that can point out which particular populations may become foci of further spread. Specifically, our work aimed to develop statistical models that identify hotspots of invasive plant species and evaluate the conditions that give rise to successful populations of invasive species. 2. We combined extensive data sets on invasive species richness and on species per cent ground cover, together with climate, local habitat and land cover data. We then estimated invasive species richness as a function of those environmental variables by developing a spatially explicit generalized linear model within a hierarchical Bayesian framework. In a second analysis, we used an ordinal logistic regression model to quantify invasive species abundance as a function of the same set of predictor variables. 3. Our results show which loc...
Bookmarks Related papers MentionsView impact
Restoration Ecology
A high proportion of regional plant biodiversity occurs in hotspots of species richness that cove... more A high proportion of regional plant biodiversity occurs in hotspots of species richness that cover small areas created and maintained by disturbance. Sustaining plant diversity in these areas requires region‐ and habitat‐specific management of disturbance and, increasingly, habitat expansion or restoration to offset species losses. Coastal sandplain grasslands are threatened, disturbance‐controlled plant biodiversity hotspots in the northeastern United States. We formed a network of grassland managers and scientists to review the published and unpublished sandplain grassland literature. Additionally, we conducted interviews with grassland managers about management challenges and successes. Principal concerns of managers were increases in woody plant cover, losses of rare species, increased cover and variety of invasive species, and constraints on the ability to use prescribed fire. The literature review and managers' experiences together led to the following recommendations: (1)...
Bookmarks Related papers MentionsView impact
Plant Ecology, 2015
Bookmarks Related papers MentionsView impact
Rhodora, 2017
Bookmarks Related papers MentionsView impact
BioScience, 2011
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Proceedings of the National Academy of Sciences
Forecasting ecological responses to climate change, invasion, and their interaction must rely on ... more Forecasting ecological responses to climate change, invasion, and their interaction must rely on understanding underlying mechanisms. However, such forecasts require extrapolation into new locations and environments. We linked demography and environment using experimental biogeography to forecast invasive and native species’ potential ranges under present and future climate in New England, United States to overcome issues of extrapolation in novel environments. We studied two potentially nonequilibrium invasive plants’ distributions, Alliaria petiolata (garlic mustard) and Berberis thunbergii (Japanese barberry), each paired with their native ecological analogs to better understand demographic drivers of invasions. Our models predict that climate change will considerably reduce establishment of a currently prolific invader (A. petiolata) throughout New England driven by poor demographic performance in warmer climates. In contrast, invasion of B. thunbergii will be facilitated becaus...
Bookmarks Related papers MentionsView impact
Rhodora
There is nothing so wonderful as a botanical foray to a new area. Your pack may have a water bott... more There is nothing so wonderful as a botanical foray to a new area. Your pack may have a water bottle, a hand lens, a field notebook (a vasculum if you were Les Mehrhoff), and perhaps a small press. What about a field guide? In New England, which current tome or doggedear guide from decades past would you toss into your pack? The new Wildflowers of New England may be just that field guide. Ted Elliman’s Wildflowers of New England is a field guide of the classic Peterson’s format covering over 1100 forbs and small flowering shrubs of the region. In my tenure as a field biologist/plant ecologist, I have longed for a regional field guide such as this; New England-centric with current taxonomic information, color pictures, and easy-to-use keys. This is both for my own use as well as a guide to recommend to newcomers to New England, budding botanists, interns, and students interested in New England botany at any level. This is the first field guide I have seen from any region that bridges the gaps between on-line databases/flora and systematic keys. Being a compendium of sorts to the 2011 Flora Novae Angliae as well as the popular Go Botany on-line key, Wildflowers of New England serves its purpose well as an easy-to-use hands-on guide with accurate information for the most likely plants. Author Ted Elliman uses his vast knowledge of the flora of the New England region to detail telltale characteristics of the New England flora. Ted Elliman, staff botanist at the New England Wildflower Society, has decades of experience all across New England. He is a thoughtful, careful botanist and conservationist. The New England Wildflower Society, and Ted himself, have made significant contributions to the conservation of species and habitats in New England. This field guide is a testament to that work and to NEWFS’ continued mission to educate the public about plant conservation in the region. When I first got my copy, I was immediately swayed by having one of my favorite spring wildflowers on the cover. Commonly called Quaker-ladies where I live on Nantucket Island, Houstonia caerulea (a.k.a. bluets) graces the front cover. The wonderful macro photogra-
Bookmarks Related papers MentionsView impact
Rhodora, 2015
The consequences of initial variability in reproductive effort on later pollination and fruit dev... more The consequences of initial variability in reproductive effort on later pollination and fruit development have frequently been investigated with flower removal experiments. Often, plants produce many fewer fruits than flowers, so flower removal might not be expected to alter subsequent growth or development patterns all that much. Yet, many studies have demonstrated such changes even for species with low average fruit set, which begs for an explanation. Many (at least seven, by our count) such explanations have been reported in the literature, but experimental support for most is limited. In summer 2014, we conducted a field experiment on a lowbush blueberry (Vaccinium angustifolium) farm in Maine. In this experiment, we coupled flower removal with three other treatments, each designed to assess the validity of one of three often-cited hypotheses invoked to explain why growth and development changes occur following flower removal: 1) “Short-term nutrient shortages;” 2) “spatiotemporal limitations;” and 3) “the compound interest effect.” The three respective treatments—foliar nitrogen fertilization, positionally biased flower removal, and defoliation—were designed to either intensify or weaken the apparent effects of flower removal if the corresponding hypothesis had merit. As in a 2013 preliminary experiment, flower removal elicited several statistically significant growth and development changes in blueberry, including increases in final leaf area, ripe fruit weight, fruit ripening rate, and relative fruit production. The additional treatments also elicited several significant plant responses, though not always with concomitant flower removal effects as well. For example, fertilization generally increased fruit cluster mass by harvest, but flower removal itself had no such effect on cluster mass. Most observed interactive effects between flower removal and the additional treatments either ran counter to expectations, were limited in scope, or couldn't be unambiguously interpreted. For at least a few observed changes, none of the additional treatments significantly altered the effects of flower removal. We conclude that current hypotheses for the mechanistic basis for changes induced by flower removal are inadequate, at least for blueberry, a species with frequently low fruit set even when managed commercially. However, strong intellectual and economic imperatives exist to encourage further investigation into this open question.Plants grown in horticulture or occurring as adventives outside their native range can provide insight into species’ fundamental niche requirements that might not be evident from the native range, or realized niche, alone. Such occurrences can also identify conditions that support individual survival, but do not currently sustain positive population growth (i.e., a species’ ‘tolerance niche’). Further, in the context of rapid climate change, horticultural and adventive occurrences beyond current range edges might circumvent natural dispersal limitations and facilitate species range shifts. To explore these concepts in the field, we investigated the history and structure of five newly discovered populations of naturalized Magnolia tripetala near horticultural sites in western Massachusetts, USA. This tree species is native to the southeastern US, but has been grown horticulturally in the Northeast since the 1800s. However, naturalized populations had not been well documented in the region previously, raising the possibility that the species’ escape has been triggered by recent climate change. With tree coring and life stage surveys, we asked whether the naturalized populations exhibited synchronous patterns of establishment and expansion, suggestive of climatic release and a shift from tolerance niche to fundamental niche conditions in the region. Across the five sites, we documented 660 individuals, with populations ranging in size from 46 to 396 individuals, including seedlings, saplings, and reproduct
Bookmarks Related papers MentionsView impact
Background/Question/Methods As part of a multi-scale project to predict invasive plant spread in ... more Background/Question/Methods As part of a multi-scale project to predict invasive plant spread in response to climate and land-use change, we are evaluating the environmental conditions that facilitate the establishment of three invasive alien species (IAS) in New England. Previously developed predictive models have highlighted areas of northern New England currently lacking IAS as places where these species may potentially thrive. As these IAS move northward, they will encounter novel conditions affecting establishment and growth. How these species respond will influence their further spread and impact across the region. We established a regional transplant experiment to test predictive model results and to estimate the colonization potential for three common IAS in New England: Berberis thunbergii, Celastrus orbiculatus, and Alliaria petiolata. Native analogs to each of these species were selected to quantify response differences; Lindera benzoin, Vitis labrusca, and Arabis glabra....
Bookmarks Related papers MentionsView impact
Background/Question/Methods Invasive species’ geographic distributions are often not at equilibri... more Background/Question/Methods Invasive species’ geographic distributions are often not at equilibrium in their invasive ranges. Therefore, invasion risk based on current occurrence patterns may lead to biased estimates of the locations at risk of invasion. We took an experimental biogeographical approach to investigating the underlying demographic processes that drive population dynamics across a range of potentially invasible environmental conditions. By linking demographic rates (growth, survival, fecundity) to explanatory environmental variables we obtained a mechanistic basis for determining species range limits. These mechanisms are particularly important for understanding invasive species distributions to improve early detection abilities for species with nonequilibrium distributions. We investigated population dynamics of two invasive species: a monocarpic biennial (Alliaria petiolata; garlic mustard) and a woody shrub (Berberis thunbergii; Japanese barberry) and two native eco...
Bookmarks Related papers MentionsView impact
Background/Question/Methods Knowledge of a species' range limit is important when triaging fo... more Background/Question/Methods Knowledge of a species' range limit is important when triaging for non-native invasive species management. With invasive species, we often have limited data at the early stages of invasion as species are not at equilibrium. These species may be beyond eradication or control by the time enough demographic data are collected. Inferring population dynamics based on current locations of invasive populations may under- or over-estimate population growth rates and, thus, potential spread. Understanding how environmental variation affects demographic parameters is important in determining species range limits and to providing a mechanistic basis for understanding invasions. Mechanistic models increase our confidence when extrapolating population level patterns to a new set of conditions or novel landscape. We investigated establishment dynamics of two non-native invasive species; the woody Berberis thunbergii and the monocarpic biennial Alliaria petiolata, a...
Bookmarks Related papers MentionsView impact
Phenotypic plasticity may be an important contributor to the success of many invasive plant speci... more Phenotypic plasticity may be an important contributor to the success of many invasive plant species. Shifts in genotype induced by the recipient environment can also lead to a range of phenotypic expression not seen in the native range. Selection for these novel genotypes could lead to local adaptation in the introduced environment. To investigate plasticity and local adaptation in an invaded region, we established three reciprocal transplant gardens using clonal replicates from two common invasive species in New England, Berberis ...
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact