Gary N Ervin

Mississippi State University | MSU · Department of Biological Sciences

Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn. (Pampas grass) is a perennial grass native to temperate and subtropical regions of South America. The species was introduced to western Europe for ornamental purposes during the nineteenth century, where it has become naturalized in anthropogenic and natural habitats, especially in sandy, o...

were penoxsulam, bispyribac-sodium, imazamox, flu-ridone, and topramezone. The control effect of these treatments was measured as percent biomass reduction 12 weeks after treatment. These data showed that, with the exception of bispyribac-sodium, submersed herbicide application was generally successful at reducing alligatorweed biomass. Also, thrip...

Literature describing effective control measures for the floating-leaved plants American lotus (Nelumbo lutea Willd.), white waterlily (Nymphaea odorata Aiton), and watershield (Brasenia schreberi J.F. Gmel.) is minimal as these are usually considered as desirable species. However, floating-leaved plants can cause ecological, economic, and social p...

Aquatic plants play a critically important role in maintaining ecosystem health. They are natural biological filters in freshwater and estuarine wetlands; they contribute to the reproductive success of many organisms, some of which are harvested for food; they assist in flood control; and they are prominent elements in the aesthetics and recreation...

Invasive plant management is a costly endeavor, with new areas constantly being invaded and new invaders perpetually appearing. Managers need to be efficient in how they use the limited resources they have for management activities, especially when managing large areas or extensive invasions. While a large body of developed mathematical models pred...

This study aimed to evaluate the effect of forest roadside on plant diversity and composition in the Hyrcanian temperate forest of northern Iran. To collect vegetation data, 116 rectangular sampling plots were established at two microhabitats (i.e., cut and fill slopes) of forest roads. For both microhabitats, the highest life form belonged to hemi...

Fruiting in angiosperms is a complex process that is partially influenced by the external environment. In the case of invasive Alternanthera philoxeroides, introduction of this species to multiple global regions may have caused the failure of its sexual reproductive system due to genetic bottleneck and a propensity for clonal propagation. Alternant...

Limnobium spongia (frogbit) is a free-floating aquatic plant that can produce extensive floating mats causing negative ecological, social, and economic impacts that can harm aquatic fauna (i.e., dissolved oxygen depletion) and restrict human uses of water. Literature describing effective control measures for frogbit is minimal. Efficacy of high and lo...

Invasive aquatic plants have the capacity to fundamentally alter the structure and function of the systems they inhabit. Alternanthera philoxeroides (alligator weed) is an emergent aquatic amaranth that is native to South America and invasive in many regions globally. Historically, invasion (and management as a result) has been most intense in the...

The ability to predict the impact of abiotic stressors on plant assemblage characteristics during habitat restoration is critical in the success of targeted restoration efforts. In an effort to determine wetland plant responses to common agricultural stressors, we seeded 75 mesocosms with soil collected from three restored wetlands in the Mississip...

Invasive aquatic plants have the capacity to fundamentally alter the structure and function of the systems they inhabit. Alternanthera philoxeroides (alligator weed) is an emergent aquatic amaranth that is native to South America and invasive in many regions globally. Historically, invasion (and management as a result) has been most intense in the...

Invasive aquatic plants have the capacity to fundamentally alter the structure and function of the systems they inhabit. Alternanthera philoxeroides (alligator weed) is an emergent aquatic amaranth that is native to South America and invasive in many regions globally. Historically, invasion (and management as a result) has been most intense in the...

In this chapter, we present and discuss information regarding biological invasions by species in the genus Baccharis L. around the world: in native, expansive, and introduced distributional ranges. Baccharis halimifolia L. is the invasive species par excellence of this genus. Therefore, we dedicate a great part of the chapter to describe (1) its di...

Aim Humans influence species distributions by modifying the environment and by dispersing species beyond their natural ranges. Populations of species that have established in disjunct regions of the world may exhibit trait differentiation from native populations due to founder effects and adaptations to selection pressures in each distributional re...

ContextInvasive plants cause significant impacts in forested areas throughout the world. However, little is known about the relative importance of environmental drivers on the establishment and spread of invasive plants across forests at broader spatial scales.Objectives We evaluated which factors are more closely associated with successful plant i...

Wetlands are unique, highly biodiverse ecosystems of high conservation value that provide multiple ecosystem services to human society. However, the dynamic nature of wetlands creates abundant opportunities for the establishment and spread of invasive species, especially those well adapted to the current global prevalence of environmental change. W...

Invasive plants are widely spread throughout the forests of the southern United States (US) and are expected to rapidly increase their distributional ranges over the next few decades. Multiple studies have shown that invasive plants pose great challenges to forest regeneration at local spatial scales; however, little is known about how those local-...

Quantitative integration of factors that potentially affect exotic species richness and abundance at multiple spatial scales is relatively scarce in the literature. Our aim was to address this gap by evaluating the relative importance of the biotic community, abiotic factors, and landscape characteristics on the establishment and spread of native a...

Invasive species are widely recognized as a major threat to global diversity and an important factor associated with global change. Species distribution models (SDMs) have been widely applied to determine the range that invasive species could potentially occupy, but most examples focus on predictive variables at a single spatial scale. In this stud...

Evolutionary and transgenerational processes affect offspring trait expression. We examined the influence of local adaptations, maternal environment, maternal traits, and changes in seedling environment on progeny performance of Baccharis halimifolia under different salinity and light levels. Over 34500 seeds from 72 mother plants from 6 native, ex...

The spatial expansions of invasive organisms in the novel range are generally expected to follow an isolation-by-distance relationship (IBD) if the invasion is biologically driven; however, many invasions are facilitated anthropogenically. This research focused on the extant expansion patterns of cogongrass (Imperata cylindrica). Cogongrass is a wi...

In early successional stages, seedlings serve as a link between past and future wetland plant assemblages. Our objectives were to 1) enumerate seedling density in soil exposed to various hydrologic treatments 2) determine similarities between standing vegetation, germinated seedlings, and early successional stage assemblages, and 3) better understa...

Limnobium spongia (frogbit) is a free-floating aquatic plant that can produce extensive floating mats that cause negative impacts to waterbodies. Literature describing effective control measures for frogbit and possible changes in water quality following herbicide treatment of aquatic plants is minimal. Control efficacy and water quality impacts of...

Transportation systems cause multiple ecological impacts by altering biotic and abiotic conditions that affect ecosystem structure and functioning from local to regional scales. I am testing the hypotheses that current and future distribution of exotic species are greatly favored by transportation systems and their adjacent land (e.g., roadsides)....

Roads cause multiple ecological impacts by altering biotic and abiotic conditions that affect ecosystem structure and functioning from local to regional scales. Roadside plant assemblages are driven by the interplay between propagule arrival and seedling establishment, which are highly influenced by roadside characteristics, landscape configuration...

Predictive models are central to many scientific disciplines and vital for informing management in a rapidly changing world. However, limited understanding of the accuracy and precision of models transferred to novel conditions (their ‘transferability’) undermines confidence in their predictions. Here, 50 experts identified priority knowledge gaps...

Over the last century, flowering rush (Butomus umbellatus L.: Butomaceae) has escaped its native Eurasian range and has become a problematic species in parts of North America. As an aquatic invasive species, flowering rush has degraded wetlands in introduced areas and has interfered with human water usage. Although experimental work has been publis...

Water quality degradation from excessive fertilizer use and runoff is a worldwide problem. While this degradation impacts wetlands, these systems can also be a vehicle for water quality improvement. Restoration of wetlands in agricultural landscapes has recently increased, but little work has evaluated the relationship of plant assemblages and wate...

The Mississippi Alluvial Valley provides important habitats for migrating and wintering waterfowl and is a priority area for restoration of wetlands through the U.S. Department of Agriculture's Wetlands Reserve Program (WRP). Management of WRP wetlands varies from no management to active annual management of vegetation and water levels, which may i...

The Mississippi Alluvial Valley provides important habitats for migrating and wintering waterfowl and is a priority area for restoration of wetlands through the U.S. Department of Agriculture's Wetlands Reserve Program (WRP). Management of WRP wetlands varies from no management to active annual management of vegetation and water levels, which may i...

The Mississippi Alluvial Valley provides important habitats for migrating and wintering waterfowl and is a priority area for restoration of wetlands through the U.S. Department of Agriculture's Wetlands Reserve Program (WRP). Management of WRP wetlands varies from no management to active annual management of vegetation and water levels, which may i...

Insects are highly underrepresented in the phylogeographic literature of the coastal plain region of the southeastern U.S., but they may contribute much to understanding the phylogeographic history of the area. The present study uses Melitara prodenialis Walker, a cactus‐boring moth, to test two alternative hypotheses: Pleistocene changes in enviro...

Interspecific hybridization is cited as one potential mechanism for increased invasiveness, particularly among some grass species. In the southeastern United States, the successful invasion of cogongrass (Imperata cylindrica) has sometimes been attributed to hybridization with the previously naturalized Imperata brasiliensis. This research aimed to...

Propagule pressure significantly contributes to and limits the potential success of a biological invasion, especially during transport, introduction, and establishment. Events such as multiple introductions of foreign parent material and gene flow among them can increase genetic diversity in founding populations, often leading to greater invasion s...

Despite their recognized importance in the literature, the contribution of native-range species interactions to invasion success has been inadequately studied. Previous authors have suggested that biases in the sampling of propagules from the native range might influence invasion success, but most contemporary invasion hypotheses focus on the devel...

The cost of controlling the spread of invasive species is exorbitant with estimates of the annual cost of control exceeding the budget of the Department of Homeland Security. Exotic insect herbivores are especially problematic because their hosts are frequently agricultural crops whose damage is also very costly. Understanding the mechanisms that g...

The Wetland Reserve Program (WRP) prescribes management of vegetation in moist-soil wetlands for waterfowl and other wildlife. This study used a block design on 18 sites in the Mississippi Alluvial Valley (MAV) in Mississippi to evaluate effectiveness of management prescriptions. Objectives were to determine appropriate timing of vegetation surveys...

We examined the association between the exotic South American cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), and its host plants (prickly pear cacti, subfamily Opuntioideae) in Florida to assess the role of host plant identity and local host community on the prevalence of this invasive moth. From May to September 2008, we surve...

Defense-free space resulting from coevolutionarily naïve host plants recently has been implicated as a factor facilitating invasion success of some insect species. Host plants, however, may not be entirely defenseless against novel herbivore threats. Volatile chemical-mediated defense signaling, which allows plants to mount specific, rapid, and int...

Environmental niche models (ENMs) have gained enormous popularity as tools to investigate potential changes in species distributions resulting from climate change and species introductions. Despite recognition that species interactions can influence the dynamics of invasion spread, most implementations of ENMs focus on abiotic factors as the sole p...

Opuntia ficus-indica (L.) Miller is a globally important cactus species with a long history of human use. In addition to the importance of O. ficus-indica as a food for humans and livestock, it also has long served a role in the production of cochineal, a once important textile dye. This cactus also is intimately interwoven into the story of Cactob...

Species distribution modeling is a tool that is gaining widespread use in the projection of future distributions of invasive species and has important potential as a tool for monitoring invasive species spread. However, the transferability of models from one area to another has been inadequately investigated. This study aimed to determine the degre...

Dense stands of Arundinaria species, or canebrakes, once were a dominant landscape feature along floodplains of the southeastern United States. However, human activities have reduced canebrakes to fragmented remnants representing <2% of their extent prior to European settlement. Canebrake restoration thus is a top priority for preserving and improv...

Background/Question/Methods The arrival of Cactoblastis cactorum (Prickly-pear moth) to North America has raised concern about the potential damage and devastating effect it will have on native Opuntia cactus if it were to reach south Texas and northern Mexico. Opuntia is used as food for humans as well as forage for livestock. It is also used fo...

Background/Question/Methods Detailed ecological understanding of invasive species is expected to facilitate the mitigation of financial costs and losses in ecosystem services resulting from species invasions. Although invasive plant species have been well-studied in terms of ecological phenomena associated with establishment and spread, we still...

Spread of the invasive cactus-feeding moth Cactoblastis cactorum has been well documented since its export from Argentina to Australia as a biocontrol agent, and records suggest that all non-native populations are derived from a single collection in the moth’s native range. The subsequent global spread of the moth has been complex, and previous res...

The quasi-experimental approach of before–after control–impact (BACI) sampling can help decide when changes are due to human activities rather than natural variability. Detailed arguments for and against BACI designs and analytic methods are widespread in the literature, but far less attention has been paid to the mechanics of analyzing a BACI expe...

Many authors have demonstrated the importance of information from species native ranges in advancing the understanding of invasions; however, others have shown that even with such information, invasions can remain unpredictable. These variable results suggest that there are components of species biology missing from such efforts. We used environmen...

Cogongrass is a highly invasive, perennial grass that is found on all continents, except Antarctica. It continues to spread at an alarming rate in the southeastern United States. Cogongrass has been reported from a wide array of habitats; however, soils from areas where cogongrass grows have never been characterized. Live cogongrass plants, herbari...

Background/Question/Methods Successful species invasions involve numerous ecological processes operating at multiple spatial and temporal scales. Sites must first meet basic physiological constraints; the boundaries of these suitable conditions are defined by the invader’s fundamental niche. If the invader is introduced into a highly suitable sit...

Background/Question/Methods Induced defenses, those that are synthesized only upon perceived attack, are an important part of the defense arsenal against insect herbivores. It is known that plants release volatile chemicals when they are attacked by herbivores, and some of these chemical cues attract insect parasitoids that act as plant defenders....

This paper presents results on nutrient concentrations estimations in the Upper Tombigbee watershed (northern Mississippi-Alabama region, USA). It details the hydrological model development and its use for providing stream flow, runoff, and nutrient concentrations (total phosphorus, TP, and total nitrogen, TN) for subsequent biological studies. Geo...

This paper presents results on nutrient concentrations estimations in the Upper Tombigbee watershed (northern Mississippi-Alabama region, USA). It details the hydrological model development and its use for providing stream flow, runoff, and nutrient concentrations (total phosphorus, TP, and total nitrogen, TN) for subsequent biological studies. Geo...

Cogongrass is a highly invasive perennial grass that threatens agriculture, forestry, and native plant assemblages in many regions of the world. Cogongrass is a prolific seed producer, but the ecological importance of seeds as a vector of invasion has not been adequately addressed. Propagule pressure plays a key role in many successful invasions an...

Background/Question/Methods We examined the association between Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) and its prickly pear host plants (subfamily Opuntioideae) in Florida in order to assess the role of host assemblage diversity in the spread of this invasive South American moth. We measured the prevalence of C. cactorum infestation...

In situ decomposition of above and belowground plant biomass of the native grass species Andropogon glomeratus (Walt.) B.S.P. and exotic Imperata cylindrica (L.) Beauv. (cogongrass) was investigated using litter bags over the course of a 12month period. The above and belowground biomass of the invasive I. cylindrica always decomposed faster than th...

Baccharis halimifolia (Eastern Baccharis, Silverling, Groundsel-bush, or Salt-bush) (Asteraceae), a weedy shrub native to the US Gulf and Atlantic Coastal Plains, is believed to be expanding its distribution throughout much of its native range and in other regions of the globe to which it has been introduced (e.g., Australia and Mediterranean Europ...

The goal of this project is improved watershed-wide decision support for resource management agencies. Improved hydrologic and water quality data collection, analysis, and simulation tools are demonstrated on selected catchments of the Mobile River watershed. Four interconnected processes are evaluated in this study: rainfall-runoff generation; sed...

Background/Question/Methods The ability to predict the successful invasion of plant species into newly disturbed habitats has the potential to substantially increase the efficiency of early detection of nascent populations of key invaders. The integration of landscape ecology and predictive habitat modeling is a promising research area that may p...

A preliminary checklist of exotic plants in Mississippi

Length-mass equations are valued for their efficiency and reliability because many animals, including aquatic macroinvertebrates, show predictable correlations between mass and linear body dimensions. Our paper explores overlooked aspects of length-mass applications, including relationships for adult aquatic insects, intraspecific variation, and sp...

Although most investigations of clonal plants have focused on negative aspects of interactions with neighbors, some studies have shown positive effects of clonal plants on other species, especially clonal plants with a compact, or phalanx, growth habit. For example, several plant species have been observed to grow directly upon tussocks of the fres...

Although most investigations of clonal plants have focused on negative aspects of interactions with neighbors, some studies have shown positive effects of clonal plants on other species, especially clonal plants with a compact, or phalanx, growth habit. For example, several plant species have been observed to grow directly upon tussocks of the fres...

Shortcuts to measuring biodiversity enable prioritization of conservation effort in the face of limited time, personnel and funding. The conservation umbrella approach focuses management effort according to individual species that may confer protection to a larger community. This approach can help guide the management agenda towards attainable goal...

We evaluated a potential index for quantifying wetland floristic quality, based on the Floristic Quality Assessment Index (FQAI) developed and tested in other regions of the United States. Principal reasons for this study were 1) FQAI is based on plant species’ coefficients of conservatism, which are unavailable for most of the world and 2) FQAI va...

We assessed wetland invasibility by conducting surveys of three wetlands in each of five categories (riverine, depression, lacustrine fringe, mineral flat, and seepage slope). Invasibility was measured as the number of invasive species present, percent of plant species classified as invasive, percent cover of invasive plants, and percent of total c...

Local abundance of animals with aquatic and terrestrial life stages may be useful to determine criteria for protective buffers around wetlands. Maiden flights and daily commutes of adult Odonata (damselflies, dragonflies) occur between wetland breeding area and adjacent upland habitat used for foraging, maturation, and nocturnal roosting. We measur...

Local abundance of animals with aquatic and terrestrial life stages may be useful to determine criteria for protective buffers around wetlands. Maiden flights and daily commutes of adult Odonata (damselflies, dragonflies) occur between wetland breeding area and adjacent upland habitat used for foraging, maturation, and nocturnal roosting. We measur...

Cogongrass (Imperata cylindrica (L.) Beauv.), an invasive C4 perennial grass, negatively influences native plant communities by forming dense monotypic stands that alter ecosystem properties and lower local species diversity. A hypothesized mechanism by which cogongrass achieves competitive dominance is a novel use of below-ground vegetative distur...

Greentree reservoir management was initiated during a period when riparian forests of the Mississippi Alluvial Valley were disappearing rapidly. Greentree reservoirs (GTRs) were intended to provide a refuge for overwintering migratory waterfowl within a landscape of decreasing habitat availability. However, GTRs frequently are flooded as much as 2....

Invasive species are a known and growing threat to native ecosystems and the services they provide, and it is widely accepted that human activities contribute substantially to their spread. In a study of fifty-two north Mississippi wetlands, approximately 10% of the vascular plant species encountered were non-native, and 60% of the wetlands surveye...

We measured species richness and composition of adult Odonata and inferred habitat preferences among man-made wetland sites and surrounding tracts of natural bottomland forest. Cumulative species richness and composition were de- scribed by proportion coefficients and beta diversity indices. The three man-made sites provided open space resources, a...