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Mark A. Weaver C. Douglas Boyette Robert E. Hoagland 《Biocontrol Science and Technology》2016,26(5):640-650
Among the most important and visible weeds in the Southeastern USA is the exotic invasive vine, kudzu (Pueraria montana var. lobata). Efforts to eradicate it typically involve many years of application of restricted-use pesticides. Recent availability of effective, non-restricted-use pesticides and developments with the application of the bioherbicide Myrothecium verrucaria has made possible new control programmes for kudzu management. Field trials at three sites over two years with aminocyclopyrachlor, aminopyralid, fluroxypyr, metsulfuron methyl and combinations of these herbicides achieved 99–100% reduction in aboveground kudzu biomass. Additionally, programmes were developed that eradicated kudzu while simultaneously establishing native vegetation. One of these successful programmes integrated bioherbicide application, mechanical removal of kudzu biomass and planting switchgrass (Panicum virgatum) in an entirely chemical herbicide-free system. These field tests demonstrate a variety of methods that can be used independently or in an integrated approach for rapid kudzu eradication. 相似文献
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Aim Biological invasion is a major conservation problem that is of interest to ecological science. Understanding mechanisms of invasion is a high priority, heightened by the management imperative of acting quickly after species introduction. While information about invading species’ ecology is often unavailable, species distribution data can be collected near the onset of invasion. By examining distribution patterns of exotic and native plant species at multiple spatial scales, we aim to identify the scale (of those studied) that accounts for most variability in exotic species abundance, and infer likely drivers of invasion. Location River Murray wetlands, south‐eastern Australia. Methods A nested, crossed survey design was used to determine the extent of variation in wetland plant abundance, grazing intensity and water depth at four spatial scales (reaches, wetland clumps, wetlands, wetland sections), and among three Depth‐strata. We examined responses of exotic and native species groups (grouped into terrestrial and amphibious taxa), native weeds and 10 individual species using hierarchical ANOVA. Results As a group dominated by terrestrial taxa, exotic species cover varied at reach‐, wetland‐ and section‐scales. This likely reflects differences in abiotic characteristics and propagule pressure at these scales. Groups based on native species did not vary at any scale examined. Cover of 10 species mostly varied among and within wetlands (patterns unrelated to species’ origin or functional group), but species’ responses differed, despite individual plants being similar in size. While flora mostly varied among wetlands, exotic cover varied most among reaches (26%), which was attributed to hydrological modification and human activities. Main conclusions Multi‐scale surveys can rapidly identify factors likely to affect species’ distributions and can indicate where future research should be directed. By highlighting disproportionate variation in exotic cover among reaches, this study suggests that flow regulation and human‐mediated dispersal facilitate exotic plant invasion in River Murray wetlands. 相似文献
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Restoration of plant communities can be hindered by the legacy of previously established invaders, despite their physical removal from the community. Current evidence, mainly built on short‐term greenhouse experiments, suggests that Sericea lespedeza (Lespedeza cuneata) invasion not only suppresses native plant species, but also alters soil conditions in host communities. As a result, L. cuneata may create a soil legacy that impedes plant community restoration. We examined the response of a Kansas grassland following L. cuneata removal to determine if historical L. cuneata abundance affected (1) plant community composition and (2) the establishment of additional native species. To address these questions, L. cuneata seeds were sown into 300 plots at a wide range of densities under different combinations of simulated disturbance and soil fertilization. After a three‐year establishment period, L. cuneata was removed from the community, and 13 native forb species were sown into all plots. Over 4 years, we found little evidence for a soil legacy effect that influenced community response post‐removal. Although there was a detectable relationship between community composition and L. cuneata, the variation explained by this relationship was very low. Similarly, the establishment of sown native species was unrelated to the historical abundance of L. cuneata. These results indicate that, regardless of initial density, L. cuneata does not impede plant community recovery in this system if effectively controlled within the first 3 years of invasion, and legacy effects inferred from greenhouse experiments may not translate to impacts on the plant community in the field. 相似文献
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Kimberly P. McCallum Martin F. Breed Andrew J. Lowe David C. Paton 《Ecological Management & Restoration》2019,20(3):222-230
The spatial arrangement of plants is a key determinant of pollination services in natural ecosystems. Despite this, plant arrangements are rarely considered an important characteristic of revegetated communities and this may be limiting successful pollination dynamics in these re‐created systems. We assessed if aggregated South Australian Blue Gum (Eucalyptus leucoxylon, F. Muell) had greater pollination success than more dispersed trees by measuring fruit set, seed production and germination in a revegetated eucalypt woodland. The proportion of buds that developed into fruit (fruit set) was similar between aggregated (five flowering Blue Gum within 30 m) and dispersed (no flowering Blue Gum within 30 m) trees (<14%). Aggregated and dispersed trees produced a similar number of seeds per fruit in 2015, when fewer trees flowered and those that flowered produced fewer flowers (ca 8 seeds/fruit). In 2016, when flowering was more abundant, aggregated trees produced more seeds per fruit than dispersed trees (12 seeds/fruit compared to 4 seeds/fruit). Despite differences in seed number, there was no difference in the quality of seed produced, indicating outcrossed pollen was received by both aggregated and dispersed trees. Although outcrossing was likely, this did not prevent pollination limitation, with the addition of outcrossed pollen increasing fruit and seed set for trees in both arrangements. Consequently, we propose that planting individuals of the same species (conspecifics) in clumps, rather than intermixing species, can increase seed set in revegetated eucalypts, particularly in good flowering years. However, aggregated plantings will be most effective if the needs and foraging behaviour of pollinators are also considered, to attract and sustain pollinators in revegetated systems, thereby minimizing the risk of pollination limitation. 相似文献
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Geetha Ramaswami Monica Kaushik Soumya Prasad Raman Sukumar David Westcott 《Biotropica》2016,48(5):638-644
In the past century, our understanding of the processes driving plant invasion and its consequences for natural and anthropogenic systems has increased considerably. However, the management of invasive plants remains a challenge despite ever more resources being allocated to their removal. Often invasive plants targeted for ‘eradication’ are well‐established, have multiple modes of reproduction, long‐term seed banks, and strong associations with native and non‐native mutualists that ensure dispersal and facilitate spread. The pantropical weed, Lantana camara (Lantana), is one of the most invasive woody plants globally. We illustrate that, for Lantana, eradication is an unrealistic management goal given the short‐term removal approaches, irrespective of the effectiveness of removal methods. We assessed the role of dispersal by avian frugivores in the recolonization of managed areas by Lantana in the seasonally dry, tropical forests of northern and southern India. We estimated the distribution of Lantana, its dispersal potential and the proximity between managed areas and source populations. We found that Lantana was dispersed by many generalist frugivorous birds and that most managed areas were well within the median dispersal distance from source plants facilitating rapid recolonization of managed areas. We conclude that given the difficulty of eradicating long‐established invasive plants, management practices should entail long‐term monitoring and control in priority areas for as long as Lantana occurs in the landscape. 相似文献
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Using a retrospective study of tamarisk removal sites across five states in the southwestern United States, we investigated (1) decreases in tamarisk cover; (2) the effects of tamarisk removal on vegetation; and (3) whether cutting or burning tamarisk has differing effects on plant communities. Our study provides an important first step in recognizing the effects of removing a dominant invasive species on meeting long-term goals of riparian restoration. We found that (1) both cutting and burning reduced mean tamarisk foliar cover by 82–95%, and this reduction was sustained over time. (2) Native foliar cover was 2- to 3-fold higher on tamarisk removal sites, but total foliar cover remained 60–75% lower than on control transects. No trend toward increases in native cover was noted over time. When tamarisk was included in the analyses, diversity in tamarisk removal sites was 2- to 3-fold higher than in the control sites and vegetation communities differed between treated and untreated sites. When tamarisk was excluded from the analyses, diversity was not greater at tamarisk removal sites, and there were no community differences between the treated and untreated transects. Differences in diversity were found to be driven by differences in evenness; overall species richness did not change following tamarisk removal. Sites in the Mojave showed the strongest increase in native foliar cover and diversity, Chihuahuan-transition sites showed a slight increase, and sites on the Colorado Plateau showed no overall increase. (3) There were no differences between plant communities at burned and cut sites. Our research indicates that vegetation response to tamarisk removal is often negligible. Land managers should be prepared for persistent depauperate plant communities following tamarisk removal if additional restoration measures are not instigated. 相似文献
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Two multi‐year field experiments investigated the effects of integrating revegetation with invasive plant management methods to rehabilitate coastal dune and woodland vegetation invaded by Bitou bush (Chrysanthemoides monilifera (L.) Norl. ssp. rotundata (DC.) Norl.) in New South Wales, Australia. The revegetation technique used was to sow directly seeds of three native species common to coastal habitats. Management treatments involved combinations of prescribed fire, manual removal of Bitou bush and an application of herbicide. Addition of native seeds significantly increased density of native species in both habitats. The benefits of manually removing Bitou bush were observed only where densities of native species were at their lowest. Fire increased densities of some native species in the woodland, but decreased those of others in the dune. Densities of Acacia longifolia ssp. sophorae (Labill.) Court (woodland) and of Banksia integrifolia L.f. (woodland and dune) were significantly reduced within 4 months of herbicide application, alone or in combination with other treatments. The majority of these effects, however, did not persist. Manual removal in both habitats and addition of seed in the woodland were most effective in reducing Bitou bush densities when applied post‐fire. Herbicide treatment on its own or in combination with other treatments did not significantly reduce Bitou bush densities by the end of the experiments. We conclude that restoration of coastal ecosystems invaded by a major invasive plant species requires a whole‐of‐system approach involving revegetation in combination with known management methods to assist recovery of native species in the longer term. 相似文献
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The introduction of an alien plant is widely assumed to have negative consequences for the pollinator‐mediated fitness of nearby natives. Indeed, a number of studies, including a highly cited meta‐analysis, have concluded that the trend for such interactions is competitive. Here we provide evidence that publication bias and study design have obscured our ability to assess the pollinator‐mediated impacts of alien plants. In a meta‐analysis of 76 studies, we demonstrate that alien/native status does not predict the outcome of pollinator‐mediated interactions among plants. Moreover, we found no evidence that similarity in floral traits or phylogenetic distance between species pairs influences the outcome of pollinator‐mediated interactions. Instead, we report that aspects of study design, such as distance between the control and nearest neighbour, and/or the arrangement of study plants better predict the impact of a neighbour than does alien/native status. Our study sheds new light on the role that publication bias and experimental design play in the evaluation of key patterns in ecology. We conclude that, due to the absence of clear, generalisable pollinator‐mediated impacts of alien species, management schemes should base decisions on community‐wide assessments of the impacts of individual alien plant species, and not solely on alien/native status itself. 相似文献
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Bradford P. Wilcox 《Ecohydrology》2010,3(1):126-130
As a result of human activities, forests and rangelands across the globe have undergone dramatic changes that have fundamentally altered ecosystem processes. Examples of these kinds of transformational changes include increasingly hot and extensive forest fires, die‐off over vast areas of forest from insect infestations, large‐scale encroachment of rangelands by woody plants and non‐native invasive plants, and desertification. These changes have accelerated in pace, scale and magnitude in recent decades and have the potential to alter water, energy, and biogeochemical cycles in important but not fully understood ways. The related disciplines of ecohydrology and watershed management are being shaped and transformed by the need to understand the ecohydrological consequences of transformative landscape change as well as the need to mitigate and manage for these changes. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Annie L. Henry;Rae Robinson;Kate Sinnott;Emily Tarsa;Mark W. Brunson;Karin M. Kettenring; 《Restoration Ecology》2024,32(5):e14167
Despite providing essential ecosystem services, wetlands are one of the most threatened ecosystems worldwide. Revegetation of wetlands is a critical aspect of restoring ecosystem services, yet little is known about common practices, the challenges managers face, or what resources they require to improve revegetation outcomes. We assessed current revegetation practices, obstacles, and potential solutions by surveying wetland managers in the Intermountain West of the United States, a vast, ecologically diverse region containing hundreds of millions of hectares of public lands. Survey results indicate that managers revegetate wetlands for erosion control, invasion resistance, enhanced wildlife habitat, and improved water quality despite small budgets and limited personnel. Drought, invasive species, and the timing and availability of water are the biggest ecological challenges that managers face and point to the need to prioritize wetland revegetation research to improve revegetation practices in a changing climate with dwindling water resources. Additionally, access to genetically- and species-diverse native plant materials is a concern for many managers. To address these challenges, managers need additional financial and human resources, accessible information relating to revegetation methods, and greater collaboration with research institutions and native plant vendors. Our findings underscore the need for funding entities to prioritize money for wetland revegetation efforts, a natural resource management area that has been neglected relative to many other ecosystems. The results of this study provide insight into challenges and potential solutions for wetland revegetation in regions of the world, such as the western United States, where increasing water scarcity threatens wetlands and their restoration. 相似文献
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The role of competition in community structure and species interactions is universal. However, how one quantifies the outcome of competitive interactions is frequently debated. Here, we review the strengths and weaknesses of the target–neighbor design, a type of additive design where one of the competing species is reduced to a single individual and where controls and analyses are used for the target, but not for the neighbors. We conducted a literature review to determine how the target–neighbor design has been typically used and analyzed. We found that historically, targets were often smaller than neighbors and introduced after neighbor establishment; thus, targets would have little effect on neighbors. However, as co‐establishment of targets and neighbors of similar size is now common, the target is more likely to affect the neighbors than in its earlier usage. This can be problematic, because if targets have a significant effect on neighbor performance, bias is introduced into the assessment of the target results. As target treatment controls are necessary to determine the absolute effect of neighbors on target growth, we advocate that analysis of the neighbor competitive response serves as a necessary control for unexpected target x neighbor interactions. 相似文献
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Elizabeth M. Phillips John K. Horne Jeannette E. Zamon Jonathan J. Felis Josh Adams 《Ecology and evolution》2019,9(8):4805-4819
Studies estimating species' distributions require information about animal locations in space and time. Location data can be collected using surveys within a predetermined frame of reference (i.e., Eulerian sampling) or from animal‐borne tracking devices (i.e., Lagrangian sampling). Integration of observations obtained from Eulerian and Lagrangian perspectives can provide insights into animal movement and habitat use. However, contemporaneous data from both perspectives are rarely available, making examination of biases associated with each sampling approach difficult. We compared distributions of a mobile seabird observed concurrently from ship, aerial, and satellite tag surveys during May, June, and July 2012 in the northern California Current. We calculated utilization distributions to quantify and compare variability in common murre (Uria aalge) space use and examine how sampling perspective and platform influence observed patterns. Spatial distributions of murres were similar in May, regardless of sampling perspective. Greatest densities occurred in coastal waters off southern Washington and northern Oregon, near large murre colonies and the mouth of the Columbia River. Density distributions of murres estimated from ship and aerial surveys in June and July were similar to those observed in May, whereas distributions of satellite‐tagged murres in June and July indicated northward movement into British Columbia, Canada, resulting in different patterns observed from Eulerian and Lagrangian perspectives. These results suggest that the population of murres observed in the northern California Current during spring and summer includes relatively stationary individuals attending breeding colonies and nonstationary, vagile adults and subadults. Given the expected growth of telemetry studies and advances in survey technology (e.g., unmanned aerial systems), these results highlight the importance of considering methodological approaches, spatial extent, and synopticity of distribution data sets prior to integrating data from different sampling perspectives. 相似文献
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Jason T. Bried 《Restoration Ecology》2013,21(5):585-591
Abundance is an important population state variable for monitoring restoration progress. Efficient sampling often proves difficult, however, when populations are sparse and patchily distributed, such as early after restoration planting. Adaptive cluster sampling (ACS) can help by concentrating search effort in high density areas, improving the encounter rate and the ability to detect a population change over time. To illustrate the problem, I determined conventional design sample sizes for estimating abundance of 12 natural populations and 24 recently planted populations (divided among two preserves) of Lupinus perennis L. (wild blue lupine). I then determined the variance efficiency of ACS relative to simple random sampling at fixed effort and cost for 10 additional planted populations in two habitats (field vs. shrubland). Conventional design sample sizes to estimate lupine stem density with 10% or 20% margins of error were many times greater than initial sample size and would require sampling at least 90% of the study area. Differences in effort requirements were negligible for the two preserves and natural versus planted populations. At fixed sample size, ACS equaled or outperformed simple random sampling in 40% of populations; this shifted to 50% after correcting for travel time among sample units. ACS appeared to be a better strategy for inter‐seeded shrubland habitat than for planted field habitat. Restoration monitoring programs should consider adaptive sampling designs, especially when reliable abundance estimation under conventional designs proves elusive. 相似文献
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Abstract Fire is a key ecological process in several biomes worldwide. Although many conservation agencies have the protection of biodiversity as at least one of their major goals, information on the effects of fire on fauna in these biomes is fragmentary. Here we provide an overview of the published research undertaken to date on the effects of fire on fauna using examples from Southern Africa. We found that few studies have examined the effects of fire on amphibians or reptiles, and work on invertebrates is likewise sparse. The majority of studies that have been published are observational reports, and few experimental studies have been undertaken using an experimental fire regime, or over appropriately long time intervals. Replication was often not reported and where this was done, it was generally inadequate. The majority of the studies failed to report the area over which the studies were undertaken and sampling unit size was often not reported. Despite the importance of fire duration, ignition method, season and time of day of fire, few studies investigated these variables. We conclude that at present the information on the effects of fire on fauna in Southern Africa is fragmentary and, consequently, informed management decisions regarding the consequences of burning policies on the conservation of biodiversity both within and outside protected areas are problematic. We recommend that future studies, both in Southern Africa and elsewhere, be based on a suite of large‐scale and experimental approaches (the latter firmly grounded in the principles of sound experimental design), use non‐classical statistics to explore the effects of large‐scale or unreplicated fires, and where possible include baseline information such as that gathered in fragmentation experiments. 相似文献
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Bioassays and Field Studies for Allelopathy in Terrestrial Plants: Progress and Problems 总被引：1，自引：0，他引：1
Bioassays are an integral part of allelopathy research. The unsuitability of laboratory bioassays to explain field situations is discussed previously. In this article, we discuss progress in bioassay experimental design and several unresolved problems associated with research on allelopathy. The objectives of this article are to discuss problems related to (1) collection of allelopathic material for bioassay, (2) allelochemical quantification in bioassays, (3) selection of concentration of allelochemicals in bioassay, (4) selection of appropriate control, (5) interaction between allelochemicals and other substances, and (6) in situ allelochemical bioassays. We concluded that new experimental designs for in situ bioassay are needed that can account for the large number of confounding factors in a complex field environment, and can be linked to physiological monitoring of target species and biochemical monitoring of the growth medium. Referee: Dr. Stella Elakovich, Dept. of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS 390406-5043 相似文献
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David B. Lindenmayer Christopher MacGregor Nick Dexter Martin Fortescue Peter Cochrane 《Ecological Management & Restoration》2013,14(1):2-10
A 10‐year science–management partnership has focussed on three key issues within Booderee National Park in eastern Australia: the impacts of fire on native biota, the response of vertebrates to feral animal control and the control of Bitou Bush. What has been achieved to date and what are the partnership's key ingredients? 相似文献
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Erin Conlisk Alexandra D. Syphard Janet Franklin Lorraine Flint Alan Flint Helen Regan 《Global Change Biology》2013,19(3):858-869
Concern over rapid global changes and the potential for interactions among multiple threats are prompting scientists to combine multiple modelling approaches to understand impacts on biodiversity. A relatively recent development is the combination of species distribution models, land‐use change predictions, and dynamic population models to predict the relative and combined impacts of climate change, land‐use change, and altered disturbance regimes on species' extinction risk. Each modelling component introduces its own source of uncertainty through different parameters and assumptions, which, when combined, can result in compounded uncertainty that can have major implications for management. Although some uncertainty analyses have been conducted separately on various model components – such as climate predictions, species distribution models, land‐use change predictions, and population models – a unified sensitivity analysis comparing various sources of uncertainty in combined modelling approaches is needed to identify the most influential and problematic assumptions. We estimated the sensitivities of long‐run population predictions to different ecological assumptions and parameter settings for a rare and endangered annual plant species (Acanthomintha ilicifolia, or San Diego thornmint). Uncertainty about habitat suitability predictions, due to the choice of species distribution model, contributed most to variation in predictions about long‐run populations. 相似文献