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At least 667 records · Page 37Linked to original sources
USGS2006

Animal and vegetation patterns in natural and man-made bog pools: implications for restoration

1. Peatlands have suffered great losses following drainage for agriculture, forestry, urbanisation, or peat mining, near inhabited areas. We evaluated the faunal and vegetation patterns after restoration of a peatland formerly mined for peat. We assessed whether bog pools created during restoration are similar to natural bog pools in terms of water chemistry, vegetation structure and composition, as well as amphibian and arthropod occurrence patterns. 2. Both avian species richness and peatland vegetation cover at the site increased following restoration. Within bog pools, however, the vegetation composition differed between natural and man-made pools. The cover of low shrubs, Sphagnum moss, submerged, emergent and floating vegetation in man-made pools was lower than in natural pools, whereas pH was higher than in typical bog pools. Dominant plant species also differed between man-made and natural pools. 3. Amphibian tadpoles, juveniles and adults occurred more often in man-made pools than natural bog pools. Although some arthropods, including Coleoptera bog specialists, readily colonised the pools, their abundance was two to 26 times lower than in natural bog pools. Plant introduction in bog pools, at the stocking densities we applied, had no effect on the occurrence of most groups. 4. We conclude that our restoration efforts were partially successful. Peatland-wide vegetation patterns following restoration mimicked those of natural peatlands, but 4 years were not sufficient for man-made pools to fully emulate the characteristics of natural bog pools.

Freshwater Biology↗
USGS2012

Occurrence of triclosan, triclocarban, and its lesser chlorinated congeners in Minnesota freshwater sediments collected near wastewater treatment plants

The antimicrobial agents triclosan (TCS), triclocarban (TCC) and their associated transformation products are of increasing concern as environmental pollutants due to their potential adverse effects on humans and wildlife, including bioaccumulation and endocrine-disrupting activity. Analysis by tandem mass spectrometry of 24 paired freshwater bed sediment samples (top 10 cm) collected by the U.S. Geological Survey near 12 wastewater treatment plants (WWTPs) in Minnesota revealed TCS and TCC concentrations of up to 85 and 822 ng/g dry weight (dw), respectively. Concentrations of TCS and TCC in bed sediments collected downstream of WWTPs were significantly greater than upstream concentrations in 58% and 42% of the sites, respectively. Dichloro- and non-chlorinated carbanilides (DCC and NCC) were detected in sediments collected at all sites at concentrations of up to 160 and 1.1 ng/g dw, respectively. Overall, antimicrobial concentrations were significantly higher in lakes than in rivers and creeks, with relative abundances decreasing from TCC > TCS > DCC > NCC. This is the first statewide report on the occurrence of TCS, TCC and TCC transformation products in freshwater sediments. Moreover, the results suggest biological or chemical TCC dechlorination products to be ubiquitous in freshwater environments of Minnesota, but whether this transformation occurs in the WWTP or bed sediment remains to be determined.

Minnesota↗
USGS1999

A CALFED-supported study of the Delta’s foodweb base

Scientists from six universities and the US Geological Survey (USGS) have begun a new project to characterize the food resource which supports secondary production in different habitats of the Sacramento-San Joaquin Delta. The project is supported by CALFED Category III, USGS, and the IEP; it is designed to answer basic questions about the organic matter which supports biological production at the lowest trophic levels. We know, from the excellent long-term records of IEP agencies, that the abundance of zooplankton (especially native species) has declined dramatically in the past three decades. We do not understand the underlying mechanisms of these declines, but it is likely that they are the result of multiple, interacting stressors. One potential limitation of secondary production could be a sub-optimal food resource, manifested either as low quantity or poor nutritional quality of the available pools of organic matter. Some past studies support this possibility, especially for the case of benthic macroinvertebrates. The project was conceived to do the following: Identify the potential sources of organic matter (for example, phytoplankton, vascular plants, agricultural sources) in different habitats; Determine the relative food quality of each of these different sources for secondary producers, either directly or after microbial processing; and Assess the habitats and environmental conditions that provide the maximum food resources for secondary producers.

Interagency Ecological Program Newsletter↗
USGS2023

Changes in mangrove blue carbon under elevated atmospheric CO2

While there is consensus that blue carbon ecosystems, such as mangroves, have an important role in mitigating some aspects of global climate change, little is known about mangrove carbon cycling under elevated atmospheric CO 2 concentrations ( e CO 2 ). Here, we review studies in order to identify pathways for how e CO 2 might influence mangrove ecosystem carbon cycling. In general, e CO 2 alters plant productivity, species community composition, carbon fluxes, and carbon deposition in ways that enhance mangrove carbon storage with e CO 2 . As a result, a negative feedback to climate change exists whereby e CO 2 adds to mangrove’s ability to sequester additional carbon, which in turn reduces the rate by which CO 2 builds. Furthermore, e CO 2 affects warming and sea-level rise (SLR) through alternate pathways, which coinfluence the mangrove response in both antagonistic (i.e., warming = greater carbon loss to decomposition) and synergistic (i.e., SLR = greater soil carbon burial) ways. e CO 2 is projected to become a more prominent driver in the future before reaching a steady state. However, given the complexity of the interactions of biological and environmental factors with e CO 2 , long-term field observations and in situ simulation experiments can help to better understand the mechanisms for proper model initialization to predict future changes in mangrove carbon sequestration.

Ecosystem Health and Sustainability↗
USGS2005

Buffelgrass (Pennisetum ciliare) land conversion and productivity in the plains of Sonora, Mexico

Bufflelgrass ( Pennisetum ciliare syn. Cenchrus ciliaris ) is an African grass that has been widely introduced in subtropical arid regions of the world to improve rangelands for cattle production. However, it can have a negative effect on the diversity of native plant communities. Buffelgrass was introduced to Sonora, Mexico in the 1970s as a means to bolster the cattle industry. “Desmonte,” the process by which native desert vegetation is removed in preparation for buffelgrass seeding, alters the land surface such that buffelgrass plots are easily detectable from aerial and Landsat satellite images. We estimated the extent of conversion to buffelgrass in a 1,850,000 ha area centered on Hermosillo, from MSS and TM images from 1973, 1983, 1990 and 2000. We then compared the relative above-ground productivity of buffelgrass to native vegetation using Normalized Difference Vegetation Index values (NDVI) from Landsat and Moderate Resolution Imaging Spectrometer (MODIS) satellite sensor systems. Buffelgrass pastures have increased from just 7700 ha in 1973 to over 140,000 ha in 2000. Buffelgrass pastures now cover 8% of the land surface in the study area. Buffelgrass pastures have lower net primary productivity, estimated by MODIS NDVI values, than unconverted desert land. The desmonte process removes trees and shrubs, while the buffelgrass plantings are often sparse, leading to an apparent net loss in net primary production from land conversion. We recommend that the desmonte process be discontinued until its efficacy and safety for native ecosystems can be established, and that a comprehensive plan for preserving biodiversity while accomodating economic development be established for this region of the Sonoran Desert in Mexico.

Sonora↗
USGS2010

Variation in active and passive resource inputs to experimental pools: mechanisms and possible consequences for food webs

1. Cross-ecosystem movements of resources, including detritus, nutrients and living prey, can strongly influence food web dynamics in recipient habitats. Variation in resource inputs is thought to be driven by factors external to the recipient habitat (e.g. donor habitat productivity and boundary conditions). However, inputs of or by ‘active’ living resources may be strongly influenced by recipient habitat quality when organisms exhibit behavioural habitat selection when crossing ecosystem boundaries. 2. To examine whether behavioural responses to recipient habitat quality alter the relative inputs of ‘active’ living and ‘passive’ detrital resources to recipient food webs, we manipulated the presence of caged predatory fish and measured biomass, energy and organic content of inputs to outdoor experimental pools of adult aquatic insects, frog eggs, terrestrial plant matter and terrestrial arthropods. 3. Caged fish reduced the biomass, energy and organic matter donated to pools by tree frog eggs by ∼70%, but did not alter insect colonisation or passive allochthonous inputs of terrestrial arthropods and plant material. Terrestrial plant matter and adult aquatic insects provided the most energy and organic matter inputs to the pools (40–50%), while terrestrial arthropods provided the least (7%). Inputs of frog egg were relatively small but varied considerably among pools and over time (3%, range = 0–20%). Absolute and proportional amounts varied by input type. 4. Aquatic predators can strongly affect the magnitude of active, but not passive, inputs and that the effect of recipient habitat quality on active inputs is variable. Furthermore, some active inputs (i.e. aquatic insect colonists) can provide similar amounts of energy and organic matter as passive inputs of terrestrial plant matter, which are well known to be important. Because inputs differ in quality and the trophic level they subsidise, proportional changes in input type could have strong effects on recipient food webs. 5. Cross-ecosystem resource inputs have previously been characterised as donor-controlled. However, control by the recipient food web could lead to greater feedback between resource flow and consumer dynamics than has been appreciated so far.

Freshwater Biology↗
USGS2025

Module 4: Basic biology of wetland animals

An assortment of animals inhabit wetlands, with many invertebrates, amphibians and reptiles, fishes, birds, and some mammals being wetland specialists. Wetlands provide ample water, food, and cover that benefits resident animals, but periodic high floods, frequent drying, and harsh water qualities (low-oxygen, acidic, saline) can stress wetland animals. Animals that rely on wetlands have developed numerous adaptations to cope with these stresses. The animal biodiversity in wetlands is particularly valued by people, from deep historical and cultural connections, to modern ecotourists and bird watchers who observe it and hunters and anglers who appreciate the consumptive resources they provide. Animals such as alligators and beavers create or physically-modify wetland environments; this activity is called ecosystem engineering and makes these animals among the most important organisms to wetland ecology. Wetlands are high in biodiversity and support rich communities of wetland invertebrates, are primary breeding habitats for most amphibians, and nearly all migratory birds rely on wetlands during some part of their annual cycle. The interactions of animals with plants (herbivory, cutting) and each other (predation) strongly shape wetland environments and affect nutrient cycling. Human impacts on wetlands can negatively affect many animals through habitat loss and degradation, resulting in many wetland amphibians, reptiles, and birds being listed as threatened and endangered species. Thus, wetland conservation is vital to conserve many animal species.

Wetland Science & Practice↗
USGS2014

Dry forest restoration and unassisted native tree seedling recruitment at Auwahi, Maui

Efforts to restore highly degraded but biologically significant forests draw from a limited toolbox. With less than 10% of their former distribution remaining, Hawaiian dry forests, though critically endangered, remain important biological and cultural refugia. At restoration onset (1997), vegetation of restoration and control areas of degraded Auwahi dry forest, Maui Island, was similar, dominated by nonnative graminoids (restoration 78.3%; control 75.4%), especially Cenchrus ( Pennisetum ) clandestinus . In 2012, unrestored control area vegetation was basically unchanged. In contrast, in the restoration area in 2012, native shrub cover increased from 3.1% to 81.9%, and cover of nonnative graminoids declined from 75.4% to 3.3%. In 2012, nonplanted seedlings of 14 of 22 native tree species and six of seven native shrub species were observed in restoration plots; the majority (99%) were five native ( Dodonaea viscosa, Coprosma foliosa, Osteomeles anthyllidifolia, Chamaesyce celastoides, Nestegis sandwicensis ) and one nonnative species ( Bocconia frutescens ). By 2012, stem counts of native woody plants had increased from 12.4 to 135.0/100 m 2 , and native species diversity increased from 2.4 to 6.6/100 m 2 . By 2012, seven rare dry forest tree species, Charpentiera obovata, Nothocestrum latifolium, Ochrosia haleakalae, Pleomele auwahiensis, Santalum ellipticum, S. haleakalae , and Streblus pendulinus , had established seedlings and/or saplings within the restoration site, especially notable because natural reproduction is largely lacking elsewhere. Without development and implementation of appropriate management strategies, remaining Hawaiian dry forest will likely disappear within the next century. Multicomponent restoration incorporating ungulate exclusion, weed control, and outplanting as described here offers one strategy to conserve and restore tracts of high-value but degraded forests.

Hawai'i↗
USGS1983

Water quality data for selected streams tributary to the tidal Potomac River and Estuary, Maryland and Virginia, 1979-81 water years

Observations of the physical, chemical, and biological water quality of five streams draining to the tidal Potomac River and Estuary during the 1979-81 water years are tabulated. The streams sampled are Rock Creek, the Northwest and Northeast Branches of the Anacostia River, the Occoquan River, and St. Clements Creek. Samples, usually collected during storms, were routinely analyzed for sediment, biochemical oxygen demand, dissolved silica, and the total and dissolved forms of phosphorus and of nitrogen species. Additional analyses for specific conductance, chlorophyll-a, and phytoplankton abundance and generic composition were done on a few samples taken during the 1980 water year. Observations of water temperature were made during the same period. Selected measurements of the turbidity of the raw water intake for the Occoquan Water Treatment Plant also are included. (Author 's abstract)

Open-File Report↗
USGS2023

Transcriptome signatures of wastewater effluent exposure in larval zebrafish vary with seasonal mixture composition in an effluent-dominated stream

Wastewater treatment plant (WWTP) effluent-dominated streams provide critical habitat for aquatic and terrestrial organisms but also continually expose them to complex mixtures of pharmaceuticals that can potentially impair growth, behavior, and reproduction. Currently, few biomarkers are available that relate to pharmaceutical-specific mechanisms of action. In the experiment reported in this paper, zebrafish ( Danio rerio ) embryos at two developmental stages were exposed to water samples from three sampling sites (0.1 km upstream of the outfall, at the effluent outfall, and 0.1 km below the outfall) during base-flow conditions from two months (January and May) of a temperate-region effluent-dominated stream containing a complex mixture of pharmaceuticals and other contaminants of emerging concern. RNA-sequencing identified potential biological impacts and biomarkers of WWTP effluent exposure that extend past traditional markers of endocrine disruption. Transcriptomics revealed changes to a wide range of biological functions and pathways including cardiac, neurological, visual, metabolic, and signaling pathways. These transcriptomic changes varied by developmental stage and displayed sensitivity to variable chemical composition and concentration of effluent, thus indicating a need for stage-specific biomarkers. Some transcripts are known to be associated with genes related to pharmaceuticals that were present in the collected samples. Although traditional biomarkers of endocrine disruption were not enriched in either month, a high estrogenicity signal was detected upstream in May and implicates the presence of unidentified chemical inputs not captured by the targeted chemical analysis. This work reveals associations between bioeffects of exposure, stage of development, and the composition of chemical mixtures in effluent-dominated surface water. The work underscores the importance of measuring effects beyond the endocrine system when assessing the impact of bioactive chemicals in WWTP effluent and identifies a need for non-targeted chemical analysis when bioeffects are not explained by the targeted analysis.

Iowa↗
USGS2014

Controls on sediment production in two U.S. deserts

Much of the world’s airborne sediment originates from dryland regions. Soil surface disturbances in these regions are ever-increasing due to human activities such as energy and mineral exploration and development, recreation, suburbanization, livestock grazing and cropping. Sediment production can have significant impacts to human health with particles potentially carrying viruses such as Valley Fever or causing asthma or other respiratory diseases. Dust storms can cause decreased visibility at the ground level, resulting in highway accidents, and reduced visual quality in park and wildland airsheds. Sediment production and deposition is also detrimental to ecosystem health, as production reduces soil fertility at its source and can bury plants and other organisms where it is deposited. Therefore, it is important to understand how we can predict what areas are prone to producing sediment emissions both before and after soil surface disturbance. We visited 87 sites in two deserts of the western U.S. that represented a range of soil texture and surface cover types. We used a portable wind tunnel to estimate the threshold friction velocity (TFV) required to initiate sediment transport and the amount of sediment produced by the tunnel at a set wind speed. Wind tunnel runs were done before and after soil surface disturbance with a four-wheel drive vehicle. Results show that most undisturbed desert soils are very stable, especially if covered by rocks or well-developed biological soil crusts, which make them virtually wind-erosion proof. Particles at disturbed sites, in contrast, moved at relatively low wind speeds and produced high amounts of sediment. Silt was an important predictor of TFV and sediment production across all sites, whereas the influence of rock cover and biological soil crusts was site-dependent. Understanding the vulnerability of a site after disturbance is important information for land managers as they plan land use activities and attempt to mitigate the harmful effects that sediment production can have on both human and ecosystem health.

Aeolian Research↗
USGS2000

Sources and haloacetic acid/trihalomethane formation potentials of aquatic humic substances in the Wakarusa River and Clinton Lake near Lawrence, Kansas

Gram quantities of aquatic humic substances (AHS) were extracted from the Wakarusa River−Clinton Lake Reservoir system, near Lawrence, KS, to support nuclear magnetic resonance (NMR) experimental studies, report concentrations of dissolved organic carbon (DOC) and AHS, define sources of the AHS, and determine if the AHS yield sufficient quantities of haloacetic acids (HAA5) and trihalomethanes (THM4) that exceed U.S. Environmental Protection Agency (EPA) Maximum Contaminant Levels (MCL) in drinking water. AHS from the Wakarusa River and Clinton Lake originated from riparian forest vegetation, reflected respective effects of soil organic matter and aquatic algal/bacterial sources, and bore evidence of biological degradation and photodegradation. AHS from the Wakarusa River showed the effect of terrestrial sources, whereas Clinton Lake humic acid also reflected aquatic algal/bacterial sources. Greater amounts of carbon attributable to tannin-derived chemical structures may correspond with higher HAA5 and THM4 yields for Clinton Lake fulvic acid. Prior to appreciable leaf-fall from deciduous trees, the combined (humic and fulvic acid) THM4 formation potentials for the Wakarusa River approached the proposed EPA THM4 Stage I MCL of 80 μg/L, and the combined THM4 formation potential for Clinton Lake slightly exceeded the proposed THM4 Stage II MCL of 40 μg/L. Finally, AHS from Clinton Lake could account for most (>70%) of the THM4 concentrations in finished water from the Clinton Lake Water Treatment Plant based on September 23, 1996, THM4 results.

Environmental Science & Technology↗
USGS2011

Fate of 4-nonylphenol and 17β-estradiol in the Redwood River of Minnesota

The majority of previous research investigating the fate of endocrine-disrupting compounds has focused on single processes generally in controlled laboratory experiments, and limited studies have directly evaluated their fate and transport in rivers. This study evaluated the fate and transport of 4-nonylphenol, 17β-estradiol, and estrone in a 10-km reach of the Redwood River in southwestern Minnesota. The same parcel of water was sampled as it moved downstream, integrating chemical transformation and hydrologic processes. The conservative tracer bromide was used to track the parcel of water being sampled, and the change in mass of the target compounds relative to bromide was determined at two locations downstream from a wastewater treatment plant effluent outfall. In-stream attenuation coefficients ( k stream ) were calculated by assuming first-order kinetics (negative values correspond to attenuation, whereas positive values indicate production). Attenuation of 17β-estradiol ( k stream = −3.2 ± 1.0 day –1 ) was attributed primarily due to sorption and biodegradation by the stream biofilm and bed sediments. Estrone ( k stream = 0.6 ± 0.8 day –1 ) and 4-nonylphenol ( k stream = 1.4 ± 1.9 day –1 ) were produced in the evaluated 10-km reach, likely due to biochemical transformation from parent compounds (17β-estradiol, 4-nonylphenolpolyethoxylates, and 4-nonyphenolpolyethoxycarboxylates). Despite attenuation, these compounds were transported kilometers downstream, and thus additive concentrations from multiple sources and transformation of parent compounds into degradates having estrogenic activity can explain their environmental persistence and widespread observations of biological disruption in surface waters.

Minnesota↗
USGS2007

Changes in abundance and spatial distribution of geese molting near Teshekpuk Lake, Alaska: Interspecific competition or ecological change?

Goose populations molting in the Teshekpuk Lake Special Area of the National Petroleum Reserve-Alaska have changed in size and distribution over the past 30 years. Black brant (Branta bernicla nigricans) are relatively stable in numbers but are shifting from large, inland lakes to salt marshes. Concurrently, populations of greater white-fronted geese (Anser albifrons frontalis) have increased seven fold. Populations of Canada geese (Branta canadensis and/or B. hutchinsii) are stable with little indication of distributional shifts. The lesser snow goose (Anser caerulescens caerulescens) population is proportionally small, but increasing rapidly. Coastline erosion of the Beaufort Sea has altered tundra habitats by allowing saltwater intrusion, which has resulted in shifts in composition of forage plant species. We propose two alternative hypotheses for the observed shift in black brant distribution. Ecological change may have altered optimal foraging habitats for molting birds, or alternatively, interspecific competition between black brant and greater white-fronted geese may be excluding black brant from preferred habitats. Regardless of the causative mechanism, the observed shifts in species distributions are an important consideration for future resource planning. ?? 2007 Springer-Verlag.

Polar Biology↗
USGS2017

Comparison of in vitro estrogenic activity and estrogen concentrations insource and treated waters from 25 U.S. drinking water treatment plants

In vitro bioassays have been successfully used to screen for estrogenic activity in wastewater and surface water, however, few have been applied to treated drinking water. Here, extracts of source and treated water samples were assayed for estrogenic activity using T47D-KBluc cells and analyzed by liquid chromatography-Fourier transform mass spectrometry (LC-FTMS) for natural and synthetic estrogens (including estrone, 17β-estradiol, estriol, and ethinyl estradiol). None of the estrogenswere detected above the LC-FTMS quantification limits in treated samples and only 5 source waters had quantifiable concentrations of estrone, whereas 3 treated samples and 16 source samples displayed in vitro estrogenicity. Estrone accounted for themajority of estrogenic activity in respective samples, however the remaining samples that displayed estrogenic activity had no quantitative detections of known estrogenic compounds by chemical analyses. Source water estrogenicity (max, 0.47 ng 17β-estradiol equivalents (E2Eq) L−1) was below levels that have been linked to adverse effects in fish and other aquatic organisms. Treated water estrogenicity (max, 0.078 ng E2Eq L−1) was considerably below levels that are expected to be biologically relevant to human consumers. Overall, the advantage of using in vitro techniques in addition to analytical chemical determinations was displayed by the sensitivity of the T47D-KBluc bioassay, coupled with the ability tomeasure cumulative effects of mixtures, specifically when unknown chemicals may be present.

Science of the Total Environment↗
USGS2016

Effects of energy development on wetland plants and macroinvertebrate communities in Prairie Pothole Region wetlands

Energy production in the Williston Basin, USA, results in the coproduction of highly saline, sodium chloride-dominated water (brine). The Prairie Pothole Region (PPR) overlies the northeastern portion of the Williston Basin. Although PPR wetlands span a range of salinity, the dominant salt is sodium sulfate, and salinities are much lower than brine. Introduction of brine to wetlands can result in pronounced water-quality changes; however, the ecological effects of such contamination are poorly understood. We examined the effects of brine contamination on primary productivity, emergent macrophyte tissue chemistry, and invertebrate communities from 10 wetlands in the PPR. Based on a recognized Contamination Index (CI) used to identify brine contamination in the PPR, water-quality samples indicated that six wetlands were uncontaminated while four were contaminated. Across this gradient, we observed a significant decrease in above-ground biomass and a significant increase in tissue chloride concentrations of hardstem bulrush ( Schoenoplectus acutus ) with increased CI values. Additionally, a significant decrease in macroinvertebrate taxonomic richness with increased CI values was observed. These findings provide needed insight on the biological effects of brine contamination on PPR wetlands.

Journal of Freshwater Ecology↗
USGS2003

Biorecovery of gold

Recovery of ionic and metallic gold (Au) from a wide variety of solutions by selected species of bacteria, yeasts, fungi, algae, and higher plants is documented. Gold accumulations were up to 7.0 g/kg dry weight (DW) in various species of bacteria, 25.0 g/kg DW in freshwater algae, 84.0 g/kg DW in peat, and 100.0 g/kg DW in dried fungus mixed with keratinous material. Mechanisms of accumulation include oxidation, dissolution, reduction, leaching, and sorption. Uptake patterns are significantly modified by the physicochemical milieu. Crab exoskeletons accumulate up to 4.9 g Au/kg DW; however, gold accumulations in various tissues of living teleosts, decapod crustaceans, and bivalve molluscs are negligible.

Indian Journal of Experimental Biology↗
USGS2002

Perspectives on trans-Pacific biological invasions

Trans-Pacific biological invasion is one of the most striking and influential biological phenomena occurring in modern times and the process is still accelerating, and the associated invasives form neo-disjuncts (cf. many well-known paleo-disjuncts) between eastern Asia and North America. To better understand this phenomenon and the related taxa, I address the following questions: 1) what types of species (e.g., life/growth form) have been, or are likely to be, associated with trans-Pacific (eastern Asia, North America) invasions; 2) what has happened or may happen to these species after their remote geographic separation, and 3) what aspects of these species and their native and non-native habitats should be better understood for improved control. To answer these questions, comparisons of the invasive species' characteristics in their native and invaded habitats need to be examined, including: l) genetics, 2) life history/morphology (e.g., plant size, seed size, etc.), 3) ecology (e.g., life/growth forms, pollinators, competitors), 4) distributions (e.g., range size, shape, latitude) in their native (source) and introduced (target) ranges or habitats, and 5) physical factors such as soil, water, and climate. The purpose of these studies is 1) to identify the limiting factors that restrict the distributions of exotic species in native ranges, 2) to understand why invasive species are successful in the introduced ranges, 3) to predict possible future invasions, and, ultimately, 4) to provide information for more efficient and effective management.

Acta Phytoecologica Sinica↗