Through the widespread implementation of next-generation sequencing （NGS）, analyses of the whole genome （the entire DNA content） and the whole transcriptome （the genes being expressed） are becoming commonplace. ...Through the widespread implementation of next-generation sequencing （NGS）, analyses of the whole genome （the entire DNA content） and the whole transcriptome （the genes being expressed） are becoming commonplace. NGS enables the analysis of a vast amount of previously unattainable genetic information. Despite this potential, NGS has yet to be widely imple- mented in genetic studies of biological invasions. The study of the genomic causes and consequences of biological invasions al- lows a deeper understanding of the molecular mechanisms underpinning the invasion process. In this review, we present a brief introduction to NGS followed by a synthesis of current research in the genomics and transcriptomics of adaptation and coloniza- tion. We then highlight research opportunities in the field, including： （1） assembling genomes and transcriptomes of non-model organisms, （2） identifying genomic regions and candidate genes underlying evolutionary processes, and （3） studying the adaptive role of gene expression variation. In particular, because introduced species face a broad range of physiological and biotic chal- lenges when colonizing novel and variable environments, transcriptomics will enable the study of gene regulatory pathways that may be responsible for acclimation or adaptation. To conclude, we identify a number of research approaches that will aid our fu- ture understanding of biological invasions展开更多
The red edge region of a hyperspectral vegetation reflectance curve provides important information regarding the biochemical and biophysical parameters of plants such as stress,senescence,and chlorophyll capacity.Howe...The red edge region of a hyperspectral vegetation reflectance curve provides important information regarding the biochemical and biophysical parameters of plants such as stress,senescence,and chlorophyll capacity.However,shifts of the red edge position(REP)to longer or shorter wavelengths have also been correlated with other factors such as water content,nitrogen,and salinity.These other factors can confuse the effect of chlorophyll on REP.The objective of this study is to define two new hyperspectral curve indices,the red valley width(RVW)and the chlorophyll absorption region(CAR)that are designed to provide less-sensitive characterizations of the chlorophyll content of vegetation in order to allow better comparisons among spatially or temporally distant populations of vegetation.The RVW and the CAR are both located in the visible near-infrared portion of the light spectrum and are derived from multiple hyperspectral curve features that have been found to be correlated with chlorophyll content,thus making them less sensitive to other biophysical and biochemical factors that can affect the REP independently.The robustness of the two new features is tested using the Leaf Optical Properties Experiment database,and the findings are used to compare two populations of saltcedar(Tamarix spp.)from a native habitat in China and an invasive habitat in the USA.Saltcedar is a highly invasive plant species in the USA but does not pose the same ecological and economic threats in its native habitat throughout Eurasia.The findings are interpreted in the context of the environmental characteristics of each region.展开更多
This article is devoted to the study of the composition, diversity and distribution of non-native plant elements to the intercontinental regions of Asia on an example Trans-Baikal territory. The number of non-native p...This article is devoted to the study of the composition, diversity and distribution of non-native plant elements to the intercontinental regions of Asia on an example Trans-Baikal territory. The number of non-native plants in the Trans-Baikal areas is determined by the degree of urbanization, favorable climate and the availability of skidding ways proximal to their vicinity.展开更多
Juncus bufonius L. （Juncaceae） is recognized by the US Department of Agriculture as a weed or invasive plant. Recently, we reported on 3i bufonius L. var. bufonius associated with the native vascular plants Deschamp...Juncus bufonius L. （Juncaceae） is recognized by the US Department of Agriculture as a weed or invasive plant. Recently, we reported on 3i bufonius L. var. bufonius associated with the native vascular plants Deschampsia antarctica and Colobanthus quitensis in the environs of the Polish Arctowski Station, King George Island, in the Maritime Antarctica. In this study, we evaluated the developmental stages and morphological characteristics of J. bufonius plants cultivated in controlled conditions beginning with seeds obtained from plants of the Antarctic population. Germination occurred at 3 weeks and the germination percentage was low （22.5%）. The average time between the anthesis and seed formation was 7 weeks, similar to that reported for other species in the Juncaceae. According to data reported in the literature, Antarctic individuals were significantly smaller than their relatives growing in other conditions, except for the number of inflorescences. The morphological characteristics of a species vary according to its distribution and the edaphoclimatic environment where it occur; cosmopolitan plants shuch as J. bufonius also have reduced stature in cold environments. The low percentage germination may have been due to water availability in the plant chamber in which the study was conducted. J. bufonius is intolerant of dry environments, and once it suffers hydric stress its recovery is very low; thus, a moister environment could be beneficial. J. bufonius has become established amongst native vegetation near Arctowski Station and without careful control or eradication; it may have the potential to spread far beyond the site, as has happened with the alien grass Poa annua as human disturbance and climate warming increase.展开更多
Aims The introduction of potentially invasive species through ornamental cultivation or for rehabilitation purposes is a serious environmental problem.They cause damage to biodiversity through loss,increased mortality...Aims The introduction of potentially invasive species through ornamental cultivation or for rehabilitation purposes is a serious environmental problem.They cause damage to biodiversity through loss,increased mortality or‘in situ’selection phenomena in natural flora.Spartium junceum is a Mediterranean shrub that is not native in most areas of the Iberian Peninsula,although it is extensively grown for the rehabilitation of roadsides.We have investigated the effect on the native vegetation of an old S.junceum(Fabaceae)plantation in a conservation area in the centre of the Iberian Peninsula:the Cuenca Alta del Manzanares nature reserve in Madrid.Methods We compared S.junceum stands with the native nanophanerophytic Cistus ladanifer community at different ecosystem properties:soil properties,temporal soil seed bank contents,standing vegetation and net primary production of annual grasslands growing in these shrublands.Important Findings The results highlighted S.junceum’s ability to become established in the new environment(marginal areas of the nature reserve)and ensure its successful growth.This is more apparent in northern and eastern exposures where this formation contacts with the core of the best conserved native vegetation in the nature reserve.Soils under Spartium showed a higher nitrogen content,indicating its capacity-in common with other legumes-to fix N,and conferring an advantage over Cistus,which is N-limited.Other soil nutrients such as phosphorus,magnesium and calcium and water availability are also higher in Spartium soils than in Cistus.Phosphorus is usually a constraint for N-fixers,but in our study,it is the most significant soil variable in both shrub formations and is important to the success of Spartium.Water availability is a key factor for Mediterranean vegetation,and particularly in autumn when soils are recharged.The Spartium formation is able to retain water as its growth produces a closer canopy than Cistus,thereby preventing water evaporation and contributing to the success of this 展开更多
We develop a long-term dynamic model for controlling invasive species using the theory of cooperative games. The model is applied to control of invasive buffelgrass in the Arizona desert, which directly competes with ...We develop a long-term dynamic model for controlling invasive species using the theory of cooperative games. The model is applied to control of invasive buffelgrass in the Arizona desert, which directly competes with indigenous species and can increase wildfire risk. Interest groups care about damages to three threatened resources: saguaro, cactus, riparian vegetation, and buildings. The model optimally allocates labor and a budget to protect these resources by controlling the buffelgrass population over a multi-period planning horizon. The solution is based on computing the Shapley values for the interest groups. A homeowner strategy of creating defensible space around structures to protect against wildfire affords less protection to the other resources. A similar result holds for protection of saguaros, which are also spatially concentrated. Under the optimal solution, groups caring about spatially-dispersed, riparian vegetation would compensate homeowners and groups caring about saguaros for a reallocation of resources toward greater protection of dispersed vegetation. Results highlight the importance of the spatial configuration of players and the resources they wish to protect in invasive species control problems.展开更多
Background: The negative impacts of the exotic tree, Ailanthus altissima(tree-of-heaven, stink tree), is spreading throughout much of the Eastern United States. When forests are disturbed, it can invade and expand qui...Background: The negative impacts of the exotic tree, Ailanthus altissima(tree-of-heaven, stink tree), is spreading throughout much of the Eastern United States. When forests are disturbed, it can invade and expand quickly if seed sources are nearby.Methods: We conducted studies at the highly dissected Tar Hollow State Forest(THSF) in southeastern Ohio USA,where Ailanthus is widely distributed within the forest, harvests have been ongoing for decades, and prescribed fire had been applied to about a quarter of the study area. Our intention was to develop models to evaluate the relationship of Ailanthus presence to prescribed fire, harvesting activity, and other landscape characteristics, using this Ohio location as a case study. Field assessments of the demography of Ailanthus and other stand attributes(e.g., fire, harvesting, stand structure) were conducted on 267 sample plots on a 400-m grid throughout THSF,supplemented by identification of Ailanthus seed-sources via digital aerial sketch mapping during the dormant season. Statistical modeling tools Random Forest(RF), Classification and Regression Trees(CART), and Maxent were used to assess relationships among attributes, then model habitats suitable for Ailanthus presence.Results: In all, 41 variables were considered in the models, including variables related to management activities, soil characteristics, topography, and vegetation structure(derived from LiDAR). The most important predictor of Ailanthus presence was some measure of recent timber harvest, either mapped harvest history(CART) or LiDARderived canopy height(Maxent). Importantly, neither prescribed fire or soil variables appeared as important predictors of Ailanthus presence or absence in any of the models of the THSF.Conclusions: These modeling techniques provide tools and methodologies for assessing landscapes for Ailanthus invasion, as well as those areas with higher potentials for invasion should seed sources become available. Though a case study on an Ohio forest, these tools can be modified for展开更多
文摘Through the widespread implementation of next-generation sequencing （NGS）, analyses of the whole genome （the entire DNA content） and the whole transcriptome （the genes being expressed） are becoming commonplace. NGS enables the analysis of a vast amount of previously unattainable genetic information. Despite this potential, NGS has yet to be widely imple- mented in genetic studies of biological invasions. The study of the genomic causes and consequences of biological invasions al- lows a deeper understanding of the molecular mechanisms underpinning the invasion process. In this review, we present a brief introduction to NGS followed by a synthesis of current research in the genomics and transcriptomics of adaptation and coloniza- tion. We then highlight research opportunities in the field, including： （1） assembling genomes and transcriptomes of non-model organisms, （2） identifying genomic regions and candidate genes underlying evolutionary processes, and （3） studying the adaptive role of gene expression variation. In particular, because introduced species face a broad range of physiological and biotic chal- lenges when colonizing novel and variable environments, transcriptomics will enable the study of gene regulatory pathways that may be responsible for acclimation or adaptation. To conclude, we identify a number of research approaches that will aid our fu- ture understanding of biological invasions
基金partially supported by grants to Le Wang from the National Science Foundation(NSF)(DEB-0810933 and BCS-0822489)the US Department of Agriculture CSREES Award 2004-38899-02181+2 种基金the Open Research Development Fund,State Key Laboratory of Earth Surface Processes and Resource Ecology,Beijing Normal Universitypartially supported by grants to Amy Frazier from the NSF Integrative Graduate Education and Research Traineeship(IGERT)in Geographic Information Science(DGE-0333417)the University at Buffalo,Mark Diamond Research Foundation(SU-1107).
文摘The red edge region of a hyperspectral vegetation reflectance curve provides important information regarding the biochemical and biophysical parameters of plants such as stress,senescence,and chlorophyll capacity.However,shifts of the red edge position(REP)to longer or shorter wavelengths have also been correlated with other factors such as water content,nitrogen,and salinity.These other factors can confuse the effect of chlorophyll on REP.The objective of this study is to define two new hyperspectral curve indices,the red valley width(RVW)and the chlorophyll absorption region(CAR)that are designed to provide less-sensitive characterizations of the chlorophyll content of vegetation in order to allow better comparisons among spatially or temporally distant populations of vegetation.The RVW and the CAR are both located in the visible near-infrared portion of the light spectrum and are derived from multiple hyperspectral curve features that have been found to be correlated with chlorophyll content,thus making them less sensitive to other biophysical and biochemical factors that can affect the REP independently.The robustness of the two new features is tested using the Leaf Optical Properties Experiment database,and the findings are used to compare two populations of saltcedar(Tamarix spp.)from a native habitat in China and an invasive habitat in the USA.Saltcedar is a highly invasive plant species in the USA but does not pose the same ecological and economic threats in its native habitat throughout Eurasia.The findings are interpreted in the context of the environmental characteristics of each region.
文摘This article is devoted to the study of the composition, diversity and distribution of non-native plant elements to the intercontinental regions of Asia on an example Trans-Baikal territory. The number of non-native plants in the Trans-Baikal areas is determined by the degree of urbanization, favorable climate and the availability of skidding ways proximal to their vicinity.
基金financed by the INACH T_03-09 and INACH RG_02-13 projects of the Chilean Antarctic Institute
文摘Juncus bufonius L. （Juncaceae） is recognized by the US Department of Agriculture as a weed or invasive plant. Recently, we reported on 3i bufonius L. var. bufonius associated with the native vascular plants Deschampsia antarctica and Colobanthus quitensis in the environs of the Polish Arctowski Station, King George Island, in the Maritime Antarctica. In this study, we evaluated the developmental stages and morphological characteristics of J. bufonius plants cultivated in controlled conditions beginning with seeds obtained from plants of the Antarctic population. Germination occurred at 3 weeks and the germination percentage was low （22.5%）. The average time between the anthesis and seed formation was 7 weeks, similar to that reported for other species in the Juncaceae. According to data reported in the literature, Antarctic individuals were significantly smaller than their relatives growing in other conditions, except for the number of inflorescences. The morphological characteristics of a species vary according to its distribution and the edaphoclimatic environment where it occur; cosmopolitan plants shuch as J. bufonius also have reduced stature in cold environments. The low percentage germination may have been due to water availability in the plant chamber in which the study was conducted. J. bufonius is intolerant of dry environments, and once it suffers hydric stress its recovery is very low; thus, a moister environment could be beneficial. J. bufonius has become established amongst native vegetation near Arctowski Station and without careful control or eradication; it may have the potential to spread far beyond the site, as has happened with the alien grass Poa annua as human disturbance and climate warming increase.
基金Madrid Regional Government(REMEDINAL2 Project:S2009/AMB-1783 and REMEDINAL3-CM,S2013/MAE-2719).
文摘Aims The introduction of potentially invasive species through ornamental cultivation or for rehabilitation purposes is a serious environmental problem.They cause damage to biodiversity through loss,increased mortality or‘in situ’selection phenomena in natural flora.Spartium junceum is a Mediterranean shrub that is not native in most areas of the Iberian Peninsula,although it is extensively grown for the rehabilitation of roadsides.We have investigated the effect on the native vegetation of an old S.junceum(Fabaceae)plantation in a conservation area in the centre of the Iberian Peninsula:the Cuenca Alta del Manzanares nature reserve in Madrid.Methods We compared S.junceum stands with the native nanophanerophytic Cistus ladanifer community at different ecosystem properties:soil properties,temporal soil seed bank contents,standing vegetation and net primary production of annual grasslands growing in these shrublands.Important Findings The results highlighted S.junceum’s ability to become established in the new environment(marginal areas of the nature reserve)and ensure its successful growth.This is more apparent in northern and eastern exposures where this formation contacts with the core of the best conserved native vegetation in the nature reserve.Soils under Spartium showed a higher nitrogen content,indicating its capacity-in common with other legumes-to fix N,and conferring an advantage over Cistus,which is N-limited.Other soil nutrients such as phosphorus,magnesium and calcium and water availability are also higher in Spartium soils than in Cistus.Phosphorus is usually a constraint for N-fixers,but in our study,it is the most significant soil variable in both shrub formations and is important to the success of Spartium.Water availability is a key factor for Mediterranean vegetation,and particularly in autumn when soils are recharged.The Spartium formation is able to retain water as its growth produces a closer canopy than Cistus,thereby preventing water evaporation and contributing to the success of this
文摘We develop a long-term dynamic model for controlling invasive species using the theory of cooperative games. The model is applied to control of invasive buffelgrass in the Arizona desert, which directly competes with indigenous species and can increase wildfire risk. Interest groups care about damages to three threatened resources: saguaro, cactus, riparian vegetation, and buildings. The model optimally allocates labor and a budget to protect these resources by controlling the buffelgrass population over a multi-period planning horizon. The solution is based on computing the Shapley values for the interest groups. A homeowner strategy of creating defensible space around structures to protect against wildfire affords less protection to the other resources. A similar result holds for protection of saguaros, which are also spatially concentrated. Under the optimal solution, groups caring about spatially-dispersed, riparian vegetation would compensate homeowners and groups caring about saguaros for a reallocation of resources toward greater protection of dispersed vegetation. Results highlight the importance of the spatial configuration of players and the resources they wish to protect in invasive species control problems.
基金Funding was provided by the Joint Fire Science Program(US)(for field assistance)primarily the Northern Research Station of the USDA Forest Service(for author salaries)
文摘Background: The negative impacts of the exotic tree, Ailanthus altissima(tree-of-heaven, stink tree), is spreading throughout much of the Eastern United States. When forests are disturbed, it can invade and expand quickly if seed sources are nearby.Methods: We conducted studies at the highly dissected Tar Hollow State Forest(THSF) in southeastern Ohio USA,where Ailanthus is widely distributed within the forest, harvests have been ongoing for decades, and prescribed fire had been applied to about a quarter of the study area. Our intention was to develop models to evaluate the relationship of Ailanthus presence to prescribed fire, harvesting activity, and other landscape characteristics, using this Ohio location as a case study. Field assessments of the demography of Ailanthus and other stand attributes(e.g., fire, harvesting, stand structure) were conducted on 267 sample plots on a 400-m grid throughout THSF,supplemented by identification of Ailanthus seed-sources via digital aerial sketch mapping during the dormant season. Statistical modeling tools Random Forest(RF), Classification and Regression Trees(CART), and Maxent were used to assess relationships among attributes, then model habitats suitable for Ailanthus presence.Results: In all, 41 variables were considered in the models, including variables related to management activities, soil characteristics, topography, and vegetation structure(derived from LiDAR). The most important predictor of Ailanthus presence was some measure of recent timber harvest, either mapped harvest history(CART) or LiDARderived canopy height(Maxent). Importantly, neither prescribed fire or soil variables appeared as important predictors of Ailanthus presence or absence in any of the models of the THSF.Conclusions: These modeling techniques provide tools and methodologies for assessing landscapes for Ailanthus invasion, as well as those areas with higher potentials for invasion should seed sources become available. Though a case study on an Ohio forest, these tools can be modified for
