Invasive Plants. Restoration of Grasslands Invaded by Sericea Lespedeza
Invasive Plants. Restoration of Grasslands Invaded by Sericea Lespedeza

Author: Eric Ntiamoah

Publisher: GRIN Verlag

Published: 2020-02-14

Total Pages: 56

ISBN-13: 3346113604

DOWNLOAD EBOOK

Master's Thesis from the year 2017 in the subject Biology - Botany, grade: 3.6, Southern Illinois University at Edwardsville (Graduate School), course: Environmental Science, language: English, abstract: Sericea lespedeza is an aggressive invasive plant which can suppress and displace native plant species in grasslands and prairies in the United States. The goal of the study is to determine how large the seed bank of lespedeza might be. Furthermore, the author tries to determine if a pre-emergent herbicide treatment could suppress Lespedeza germination and whether this provided benefits to a typical native species propagated into the site. In the work, the author first characterized the soil seed bank at different invaded sites on SIUE campus using the seedling emergence method. In the second part, the author assessed the success of a pre-emergent herbicide in preventing the germination of lespedeza seed bank after lespedeza removal. The growth of a native grass (Sorghastrum nutans) as a replacement species has also been evaluated. Currently Sericea lespedeza is rapidly spreading throughout the U.S and has been estimated to eventually invade about 61percent of the total land area. Lespedeza has become a successful colonizer because of its ability to tolerate and thrive under a wide range of environmental and soil conditions. Once established, lespedeza is very difficult to remove due to its persistent seed bank which can remain viable for years. To successfully control lespedeza, we must find effective ways to suppress or kill seeds in the soil, but this has received little research attention.

Restoration of Grasslands Invaded by Sericea Lespedeza (Lespedeza Cunetea)
Restoration of Grasslands Invaded by Sericea Lespedeza (Lespedeza Cunetea)

Author: Eric Lissner Ntiamoah

Publisher:

Published: 2017

Total Pages: 46

ISBN-13:

DOWNLOAD EBOOK

Sericea lespedeza is an aggressive invasive plant which can suppress and displace native plant species in grasslands and prairies in the United States. Currently is rapidly spreading throughout the U.S and has been estimated to eventually invade about 61% of the total land area. Lespedeza has become a successful colonizer because of its ability to tolerate and thrive under a wide range of environmental and soil conditions. Once established, lespedeza is very difficult to remove due to its persistent seed bank which can remain viable for years. To successfully control lespedeza, we must find effective ways to suppress or kill seeds in the soil, but this has received little research attention. In our work, we first characterized the soil seed bank at different invaded sites on SIUE campus using the seedling emergence method. In the second part of this research, we assessed the success of a pre-emergent herbicide (Preen®) in preventing the germination of lespedeza seed bank after lespedeza removal. We also evaluated the growth of a native grass (Sorghastrum nutans) as a replacement species. The results from the soil seed bank study showed that lespedeza germinates rapidly (

Resisting Invasion
Resisting Invasion

Author: Erin Marie Medvecz

Publisher:

Published: 2017

Total Pages: 446

ISBN-13:

DOWNLOAD EBOOK

Invasive species, including Lespedeza cuneata (Dum. Cours.) G. Don, threaten the success of grassland restoration through their ability to alter species composition following invasion. Combining the filter framework model of community assembly with the passenger-driver model of non-native species behavior can clarify the broader impacts of invasive species in the communities they invade. Testing this combined theory by exploring the mechanisms by which an invasive functions (above- and belowground) and the response of native plants from different functional groups to these mechanisms can reveal if an invasive functions as a driver and a filter. Observational field surveys were conducted across fifteen L. cuneata-invaded grasslands to compare species composition of plots in which L. cuneata was either present or absent. In a greenhouse experiment, the response of natives in three functional groups--grasses, forbs, and legumes--to aboveground (competition), belowground (soil conditioning), and both above- and belowground interactions with L. cuneata were investigated. Response variables (height, leaf number, root length, biomass, specific leaf area, leaf chlorophyll, and soil pH and conductivity) were measured. Regional analysis of the field surveys did not identify distinct species compositional differences in invaded and uninvaded areas, while within-site analyses revealed differences in half of the sites, suggesting that site specific characteristics could be impacting whether L. cuneata presence corresponds with a fundamental shift in species composition. Regionally, grass and legume abundance was higher in plots not containing L. cuneata than in plots where it was present. The greenhouse experiment illustrated stronger aboveground competitive effects than belowground soil effects, with impacts differing among functional groups. Under pressure of competition with L. cuneata, grasses experienced increases in certain measured traits (height, root length and specific leaf area), while when grown in conditioned soil, grasses produced greater biomass. Additionally, the growth of L. cuneata differed when grown in competition with forbs, grasses, and legumes. Competition with legumes resulted in the most suppressed growth of L. cuneata individuals among the three functional groups. Considering the field survey and greenhouse experiments in conjunction suggests that grasses can benefit from interactions with L. cuneata and have the potential to outcompete and exclude it, while legumes are detrimental to the growth of L. cuneata and compete for niche space, resulting in L. cuneata establishment in legume-poor areas. The forb functional group did not have a significant relationship to L. cuneata presence in either the field surveys or the greenhouse experiment. Lesepedeza cuneata acts as a driver, altering the abiotic and biotic filters to impact species composition, while it does not act as a filter, with native grasses and legumes acting to filter the L. cuneata.

Responses of Grassland Birds and Butterflies to Control of Sericea Lespedeza with Fire and Grazing
Responses of Grassland Birds and Butterflies to Control of Sericea Lespedeza with Fire and Grazing

Author: Sarah B. Ogden

Publisher:

Published: 2017

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

Sericea lespedeza (Lespedeza cuneata) is an invasive forb that reduces native grass and forb abundance in tall-grass prairie by up to 92%. Controlling invasions is difficult because traditional land management tools used in the Flint Hills, broad spectrum herbicides, spring prescribed fire, and cattle grazing, are ineffective against sericea. Recent research has demonstrated, however, that mid- and late summer prescribed fire and spring fire with early season grazing by steers followed by late season grazing by sheep are effective at reducing sericea whole plant mass, number of seeds produced, and seed mass. Field results were from two separate experiments conducted in tall-grass prairie study sites in the Flint Hills. On a Geary County, Kansas, study site, the utility of 1) spring fire (control), 2) mid-summer fire, and 3) late summer fire on sericea control were compared. On a Woodson County, Kansas, study site, the utility of 1) spring fire with early season steer grazing followed by rest (control) and 2) spring fire with early season steer grazing and late season sheep grazing on sericea control were compared. At the same study sites, I measured responses by the native wildlife community to use of summer fire and sheep grazing, relative to their controls, to manage sericea lespedeza. Specifically, my objectives were to compare grassland songbird density, grassland songbird nest survival, and grassland butterfly species composition and density among treatments at both study sites. I also related patterns in the vegetation community of each treatment for each study site to respective patterns in grassland bird and butterfly communities. Within study sites, density, nest density, and nest success of grassland bird communities responded similarly to treatments and controls, with the exception that densities of Grasshopper Sparrows (Ammodramus savanarrum) were 3.4- and 2.2-fold greater in mid- and late summer fire plots than spring fire plots, respectively, in the Geary County study site. Species compositions of butterfly communities were similar across treatments within experiments, but grassland specialist species comprised only 8.6 and 1.2% of all butterfly observations in the Geary County and Woodson County experiments, respectively. Grassland specialist butterfly species may benefit from summer fire, as their nectar sources were more abundant in Summer Fire plots than Spring Fire plots. Overall, within each experiment, grassland bird and butterfly communities were similar across treatments, suggesting that treatments did not negatively affect grassland songbird and butterfly communities. I additionally demonstrated that Dickcissel (Spiza americana) nest sites contain a lower proportion of sericea than random points, the first evidence that the invasion is detrimental to grassland songbird species. Lacking control, the continued sericea invasion will out compete cumulatively more forb plants resulting in declining quality of grassland bird nesting habitat on the landscape. Controlling sericea lespedeza invasions will allow native forb species to increase in abundance and improve the condition of grasslands for native wildlife and livestock producers. Therefore, I advocate use of summer fire or spring fire with a combination of cattle and sheep grazing to control sericea lespedeza with the long-term goal of tall-grass prairie restoration.

Directing Ecological Succession
Directing Ecological Succession

Author: Seema Mangla

Publisher:

Published: 2011

Total Pages: 324

ISBN-13:

DOWNLOAD EBOOK

Successful ecosystem restoration requires an understanding of the ecological processes directing succession. One of the challenges in the semi-arid grasslands of western United States is replacement of native species by invasive annual grasses. Solutions to this problem require identifying and manipulating ecological processes that direct succession to favor desired vegetation. The overall objective of this research was to identify and understand processes or factors directing restoration of semi-arid grassland ecosystems dominated with invasive annual grasses. Two invasive annual (Bromus tectorum L. and Taeniatherum caput-medusae L. Nevski) and two native perennial (Pseudoroegneria spicata (Pursh) A) and Poa secunda J. Presl) grass species were used to provide a model system of semi-arid grasslands of western United States. Plant competition is considered to be the primary ecological process limiting the success of grassland restoration. Successful restoration requires knowing the relative strength and magnitude of competition during the early stages of plant growth and how this might be impacted by nitrogen (N) availability. My research involved three experiments designed to compare competition and growth rates of native and invasive species. First, in order to understand the degree to which intra- versus inter-specific competition controls invasive and native plant growth during the early phase of establishment, I performed a diallel competition experiment with species grown either alone or in 1:1 binary combinations in a greenhouse. I hypothesized that the type and intensity of competition for invasive and native species would vary among harvest times and competitive intensity for invasive species will be higher than native species with higher N availability. My results indicated that invasive and native species are subject to both intra- and inter-specific competition; however, the dominant type differed among harvests. Invasive species also became more competitive than native species with increasing N. I suggest that opportunities to improve restoration success exist by determining the optimum combination of density, species proportion, and their spatial arrangement in various ecosystems and environments. Second, I performed an addition series competition experiment in the field for two years to determine the intensity and importance of competition in an arid, resource poor production system. My results indicated that in resource poor environments, the intensity of competition did not significantly influence plant dominance during the first two years of plant establishment, and thus, competition was not important. I suggest that land managers may be most successful at restoration of resource poor ecosystems by overcoming the barriers associated with plant establishment other than plant-plant interactions, such as abiotic factors. Third, I studied growth rate and growth patterns of medusahead with bluebunch wheatgrass and cheatgrass in the field for two years. I hypothesized that medusahead would have a higher RGR, a longer period of growth, and as a consequence, more total biomass at the end of the growing season than bluebunch wheatgrass and cheatgrass. Medusahead had a longer period of growth, more total biomass and higher RGR than cheatgrass. However, bluebunch wheatgrass had more biomass and higher RGR than medusahead in 2008, but the relationship was reversed in 2009. Weather data identified that precipitation in 2008 was well below average, and this level of drought was very infrequent. Collectively, my results suggest that the continued invasion and dominance of medusahead onto native and cheatgrass dominated grasslands will continue to increase in severity because of its higher RGR and extended period of growth. The inability to identify key ecological processes important in directing invasion and succession has limited the adoption and implementation of ecologically based invasive plant management (EBIPM). A framework that allows ecologist to identify and prioritize ecological processes most in need of repair would help overcome this barrier. I developed an initial framework that allows ecologists to prioritize the ecological processes that appear to play a dominate role in vegetation dynamics. This was accomplished by using sensitivity analysis to identify the most important transitions in the life cycle of associated species and linking those transitions with key ecological processes and their modifying factors. This method could increase land manager's ability to implement EBIPM by allowing identification and prioritization of those ecological processes that appear to play a dominating role in vegetation dynamics.

Investigating the Role of Soil Legacy Effects and Community Engagement in the Management of Lespedeza Cuneata, an Invasive Legume
Investigating the Role of Soil Legacy Effects and Community Engagement in the Management of Lespedeza Cuneata, an Invasive Legume

Author: Matthew Steven Hodges

Publisher:

Published: 2020

Total Pages: 81

ISBN-13:

DOWNLOAD EBOOK

Invasive plant species present a growing threat to biodiversity. Many invasive plants are able to recruit microbial symbionts in their novel range and establish plant-soil feedbacks that influence growth and fitness. These alterations, referred to as soil legacy effects, can linger for decades after the removal of invasive species and impact efforts to restore native plant populations. The process of restoring organisms and their interactions with one another, referred to as ecological restoration, occurs by repairing these damages and alterations to ecosystem diversity and ecosystem dynamics. In a series of growth room experiments, I analyzed the plant-soil feedback of an invasive legume, Lespedeza cuneata, and how soil legacy effects caused by invasion and use of glyphosate herbicide influence the growth and competitive interactions of three native plant species. In contrast to studies of L. cuneata in prairie ecosystems, my investigation suggests that positive plant-soil feedback does not significantly contribute to its growth or spread in the floodplains of eastern North Carolina, as a history of invasion did not significantly improve the seed germination, seedling survival, growth, or root nodule formation of the invasive legume. The absence of evidence for positive plant-soil feedback in my experiment might be attributed to frequent flooding observed in a floodplain system and the resulting homogenization of soil biota. Findings from my study also suggest that the application of glyphosate herbicide alone creates areas where L. cuneata can readily reinvade, as it significantly reduced the number and diversity of seedlings to emerge from the seed bank while significantly increasing the aboveground biomass and nodule formation of L. cuneata. Concerning the restoration of native flora, my investigation suggests that Chasmanthium latifolium, as opposed to Solidago altissima or Chamaecrista nictitans, may be more susceptible to negative impacts caused by a L. cuneata invasion or glyphosate herbicide and therefore less suitable for initial efforts to restore populations of native flora. Results from my competition experiments also suggest that while S. altissima and Cham. nictitans may not be able to suppress populations of L. cuneata, the two native forbs would be successful in preventing areas from being reinvaded while areas occupied solely by Chas. latifolium may be at risk of reinvasion. Control of invasive species requires active participation by conservation professionals and the public. Outreach events and citizen-science programs can provide members of the community of all ages and careers the opportunity to play an active role in conservation efforts through data collection, species monitoring, restoration, invasive species removal, or a wide variety of other necessary tasks. To assess undergraduate attitudes towards conservation and involve students in the management of an invasive plant, an engagement event was held on a local greenway with an ongoing invasion of L. cuneata. During the outreach event, participants manually removed invasive plants while engaging in discussions centered on invasive species, local flora, and conservation. Voluntary participant data surveys suggested that the event positively impacted participants' perception of the natural world and encouraged them to seek out similar opportunities in the future. Survey results also showed that opinions towards conservation were influenced by the undergraduate major of students.

First Step Restoration Techniques in Invaded Grassland in Southern British Columbia
First Step Restoration Techniques in Invaded Grassland in Southern British Columbia

Author:

Publisher:

Published: 2009

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

Invasive species are considered the second greatest threat to biodiversity (after habitat loss) as they can alter ecosystem functioning, including nutrient cycling. Invasive plant species can be controlled using various methods and restoration is often attempted in degraded areas. Biological control temporarily eliminated diffuse knapweed from a site in Vernon, British Columbia, though the site remained completely dominated by other invasive species. Restoration was attempted using seed addition of native species and late summer and spring vegetation removal of invasive species. Seed addition did not result in increased native species abundance in the plots, likely because of abnormally low April precipitation. Vegetation removal in spring did not prevent the emergence of seedlings, and actually increased emergence of diffuse knapweed and thyme-leaved sandwort. Annual grasses on the other hand were more abundant in plots without vegetation removal. Removal of vegetation in the plots was not evident by biomass harvest in August, though it significantly increased diversity and the percentage of forbs in the total biomass. The plots with no vegetation removed had significantly greater percentage of grass in the total biomass and far greater litter mass. Comparing soil samples from two invaded ecosystems (diffuse knapweed and sulphur cinquefoil dominated) to one with few invasive species (bunchgrass dominated) resulted in finding that almost all nutrient levels measured and moisture were highest in the uninvaded ecosystem. As diffuse knapweed reacts positively to the removal of competition, vegetation removal should not be used as a restoration technique in invaded areas. In areas where there is no knapweed, however, vegetation removal may be beneficial to work against dominance by annual grass species. Soils of invaded ecosystems may also need to be considered, and only vegetation that can withstand drought and low levels of nutrients should be used.

Impacts of Medusahead (elymus Caput-medusae L.) Management on Plant Communities in California's Valley Grasslands
Impacts of Medusahead (elymus Caput-medusae L.) Management on Plant Communities in California's Valley Grasslands

Author: Nicole Carpenter

Publisher:

Published: 2020

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

California's valley grasslands are one of the most invaded ecosystems in the state. It is estimated that valley grasslands contain between 90 to 99% cover of non-native plants. The most recent wave of invasive plants has included medusahead (Elymus caput-medusae L.). Medusahead is an annual grass that matures two to four weeks later than most other grasses. Management of medusahead includes the use of herbicides, targeted grazing, prescribed burns, and mechanical control. The primary focus of most studies on the use of these management methods is on the control of medusahead rather than the impacts on non-target plants. This study examines published research to determine what impact medusahead management has on the composition of plant communities within valley grasslands. Herbicides have mixed impacts on the percent cover of grasses and forbs. Targeted grazing resulted in decreased percent cover of non-native grasses and increased forb cover. Grazing results in neutral to increased percent cover of native plants. Prescribed burns decreased the percent cover of non-native grasses, increased forb cover, and had mixed impacts on native plant cover. Mechanical control shifted vegetative states towards forb or filaree (Erodium spp.) dominated communities. The non-target impacts of medusahead control were generally short-lived with differences in percent cover returning to baseline conditions within one to three years. To mitigate the non-target impacts of medusahead, revegetation efforts should be prioritized in sites with higher abundances of native plant species. The future success of controlling medusahead is dependent upon grassland restoration research, consistent funding for weed management areas to aid in managing invasive plants, and the implementation of monitoring after medusahead control treatments.

Guidelines for Native Seed Production and Grassland Restoration
Guidelines for Native Seed Production and Grassland Restoration

Author: Kathrin Kiehl

Publisher: Cambridge Scholars Publishing

Published: 2014-06-19

Total Pages: 315

ISBN-13: 1443861855

DOWNLOAD EBOOK

World-wide, the degradation and destruction of both natural and traditionally used semi-natural ecosystems is drastically increasing. Unfortunately, commercial seed mixtures, consisting of non-native species and genetically uniform cultivars, are widely used in grassland restoration, often with negative effects on biodiversity. Therefore, native species should be used in the ecological restoration of natural and semi-natural vegetation. This book compiles results from recent studies presented at a Special Session “Native seed production and use in restoration projects”, which was organised during the 8th European Conference on Ecological Restoration in České Budějovice, Czech Republic. The authors review the ecological and genetic aspects of seed propagation and species introduction both from a European and an American perspective, and discuss implications for the development of seed zones and for native seed production. Examples from different countries focus on native seed production in practice, and suggest different approaches for the certification of seed provenance. Best practice examples from Europe and the United States are used to indicate the advantages of using native seeds for ecological restoration of grasslands, field margins and sagebrush steppe. Finally, this volume also provides guidelines for the successful implementation of restoration projects for local authorities, landscape planners and NGOs in order to bridge gaps between research and practice.

Short-term Intensive Management of High Densities of the Invasive Plant Sericea Lespedezea
Short-term Intensive Management of High Densities of the Invasive Plant Sericea Lespedezea

Author: Jack E. Cornell

Publisher:

Published: 2008

Total Pages: 122

ISBN-13:

DOWNLOAD EBOOK

Lespedeza cuneata (Sericea lespedeza) is a nonnative invasive legume that competively excludes native grasses and forbs. Unfortunately, typical management protocols that are used to maintain native flora in Missouri old fields and prairies, mowing and fire, enhance L. cuneata growth and seedling establishment. This study examined management strategies for communities in Missouri that have become degraded due to high density stands of L. cuneata. I tested a relatively novel management regime at Wilson's Creek National Battlefield in Springfield, Missouri to control L. cuneata that minimizes the use of herbicides and maximizes the natural competitive interactions of native species. I used an organic fertilizer (4-1-4) to increase soil quality and promote the competitive ability of native grasses and forbs. I applied a newly-developed herbicide (PastureGard, developed by DowAgro) that targets legumes and other woody species. Finally, I used mowing, which is a necessary treatment to control secondary growth in prairie habitats. I found that PastureGard effectively controlled L. cuneata (stem density per m2 was reduced from 89.4 ± 13.9 (mean ± standard deviation) to 0.0 ± 0.0 in treated plots). Fertilization reduced percent cover of L. cuneata cover from 27.2 ± 5.34 to 6.3 ± 4.2. Mowing did not have a significant effect on reducing L. cuneata dominance. Combining fertilization with herbicide did not have the desired effect of increasing species richness. Results suggest that fertilization does have potential for controlling L. cuneata in highly invaded prairies and old-fields if used in conjunction with at least one herbicide application.