scholarly journals Measuring competitive impact: joint-species modelling of invaded plant communities

2018 ◽  
Author(s):  
Andrew O'Reilly-Nugent ◽  
Elizabeth Wandrag ◽  
Jane Catford ◽  
Bernd Gruber ◽  
Don Driscoll ◽  
...  
Keyword(s):  
Plant Communities ◽  
Native Species ◽  
Plant Cover ◽  
Avena Fatua ◽  
High Fertility ◽  
Native Plant ◽  
Distribution Models ◽  
Bromus Diandrus ◽  
Fertility Gradient ◽  
Biomass Removal

1.Non-native species can dominate plant communities by competitively displacing native species, or because environmental change creates conditions favourable to non-native species but unfavourable to native species. We need to disentangle these alternative mechanisms so that management can target competitively dominant species and reduce their impacts. 2.Joint-species distribution models (JSDMs) can potentially quantify competitive impacts by examining how species respond to environmental variation and to changes in community composition. We describe a JSDM to model variation in plant cover, which detected declines in species abundance in the presence of a dominant competitor.3.We applied our model to an experiment in an invaded grassy-woodland community in Australia where we manipulated biomass removal (through slashing and grazing by kangaroos) along a fertility gradient. Non-native species dominated plant cover at high fertility sites in the absence of biomass removal. Using a JSDM, we determined that three of the 72 non-native plant species (Bromus diandrus, Acetosella vulgaris and especially Avena fatua) were having a strong competitive impact on the community, driving changes in composition and reducing the cover of both native and non-native species, particularly in the absence of grazing. The dominant annual grasses (Bromus diandrus and Avena fatua) were two of the tallest species in the community and were good competitors for light under conditions of high fertility and low grazing. Consequently, their impacts were greatest on smaller statured species.4.Synthesis. We demonstrate a method to measure competitive impact using a JSDM, identify species driving compositional change through competitive displacement, and identify where on the landscape competitive impacts are greatest. This information is central to managing plant invasions: by targeting dominant non-native species with large competitive impacts, management can reduce impacts where they are greatest. We provide details of the modelling procedure and reproducible code to encourage further application.

Regularities of sinantropization processes of the vegetation cover in the cities of the south Cis-Urals (Bashkortostan Republic)

2016 ◽  
pp. 28-36 ◽  
Author(s):  
Ya. M. Golovanov ◽  
L. M. Abramova
Keyword(s):  
Alien Species ◽  
Plant Communities ◽  
Native Species ◽  
Climatic Factors ◽  
Plant Cover ◽  
Anthropogenic Pressure ◽  
Native Plant ◽  
Anthropogenic Transformation ◽  
Native Flora ◽  
The Common

Increase of anthropogenic pressure on nature ecosystems leads to synanthropization of flora and vegetation. A replacement of native species in communities with synanthropic ones, including alien species, takes place as well as a change of native plant communities by synanthropic ones, decrease of biodiversity, simplification of structure, decrease in efficiency and stability of plant communities (Gorchakovskij, 1999). Synanthropization as an indicator of anthropogenic transformation of vegetation is a traditional object of studies (Sudnik-Wojcikowska, 1988; Abramova, 2010; Abramova, Mirkin, 2000; Abramova, Mikhailova, 2003; etc.). The ratio of synanthropic and native flora species for an assessment of synanthropization level is usually used. The assessment of synanthropization level is the most important element of monitoring as it helps to estimate a degree of ecosystems disturbance and to develop a system of their rational use and protection. Processes of synanthropization are most expressed in the towns. The towns are the heterotrophic ecosystems including uniform group of anthropogenically transformed communities formed on the residential, industrial, transport, agrarian, recreational territories where the florogenesis and the phytocoenogenesis are highly specific (Burda, 1991; Ilminskikh, 1993). The urban environment can have the leveling impact on climatic factors therefore the floras of towns in different nature zones quite often have the common features (Ilminskikh, 1993). An increase of a syntaxonomic variety due to destruction of native vegetation is compensated by increase of synanthropic syntaxa number from the synanthropic classes of vegetation, and also communities of aggressive alien species which are combined with species of local flora. The regularities of synanthropization of urban flora and vegetation are less studied (Kowarik, 1990; Burda, 1991; etc.). Due to a growth of urbanization process around the world the studying of anthropogenic transformation of ve­getation cover is required. The article is devoted to the analysis of regularities of synanthropization of plant cover in towns of the southern Cis-Urals belonging to the Southern industrial zone of Bashkortostan Republic. 3 towns — Sterlitamak, Salavat and Ishimbay representing different categories by their population size were chosen for an assessment of synanthropization level.

Competition between native and non-native plants.

2020 ◽  
pp. 291-307
Author(s):  
Elizabeth M. Wandrag ◽  
◽  
Jane A. Catford ◽  
◽  
◽  
...  
Keyword(s):  
Plant Species ◽  
Plant Communities ◽  
Native Species ◽  
Abiotic Factors ◽  
Invasion Biology ◽  
Competitive Interactions ◽  
Native Plant ◽  
Native Plant Species ◽  
New Locations ◽  
Strength Of Competition

The introduction of species to new locations leads to novel competitive interactions between resident native and newly-arriving non-native species. The nature of these competitive interactions can influence the suitability of the environment for the survival, reproduction and spread of non-native plant species, and the impact those species have on native plant communities. Indeed, the large literature on competition among plants reflects its importance in shaping the composition of plant communities, including the invasion success of non-native species. While competition and invasion theory have historically developed in parallel, the increasing recognition of the synergism between the two themes has led to new insights into how non-native plant species invade native plant communities, and the impacts they have on those plant communities. This chapter provides an entry point into the aspects of competition theory that can help explain the success, dominance and impacts of invasive species. It focuses on resource competition, which arises wherever the resources necessary for establishment, survival, reproduction and spread are in limited supply. It highlights key hypotheses developed in invasion biology that relate to ideas of competition, outlines biotic and abiotic factors that influence the strength of competition and species' relative competitive abilities, and describes when and how competition between non-native and native plant species can influence invasion outcomes. Understanding the processes that influence the strength of competition between non-native and native plant species is a necessary step towards understanding the causes and consequences of biological invasions.

Impacts of erosion control treatments on native vegetation recovery after severe wildfire in the Eastern Cascades, USA

2010 ◽  
Vol 19 (4) ◽  
pp. 490 ◽  
Author(s):  
Erich K. Dodson ◽  
David W. Peterson ◽  
Richy J. Harrod
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Native Species ◽  
Plant Cover ◽  
Plant Species Richness ◽  
Tree Regeneration ◽  
Vegetation Recovery ◽  
Native Vegetation ◽  
Individual Plant ◽  
Native Plant

Slope stabilisation treatments like mulching and seeding are used to increase soil cover and reduce runoff and erosion following severe wildfires, but may also retard native vegetation recovery. We evaluated the effects of seeding and fertilisation on the cover and richness of native and exotic plants and on individual plant species following the 2004 Pot Peak wildfire in Washington State, USA. We applied four seeding and three fertilisation treatments to experimental plots at eight burned sites in spring 2005 and surveyed vegetation during the first two growing seasons after fire. Seeding significantly reduced native non-seeded species richness and cover by the second year. Fertilisation increased native plant cover in both years, but did not affect plant species richness. Seeding and fertilisation significantly increased exotic cover, especially when applied in combination. However, exotic cover and richness were low and treatment effects were greatest in the first year. Seeding suppressed several native plant species, especially disturbance-adapted forbs. Fertilisation, in contrast, favoured several native understorey plant species but reduced tree regeneration. Seeding, even with native species, appears to interfere with the natural recovery of native vegetation whereas fertilisation increases total plant cover, primarily by facilitating native vegetation recovery.

Chinese Privet (Ligustrum sinense) Removal and its Effect on Native Plant Communities of Riparian Forests

2009 ◽  
Vol 2 (4) ◽  
pp. 292-300 ◽  
Author(s):  
James L. Hanula ◽  
Scott Horn ◽  
John W. Taylor
Keyword(s):  
Plant Communities ◽  
Foliar Application ◽  
Plant Cover ◽  
Riparian Forests ◽  
Active Management ◽  
Native Plant ◽  
Chinese Privet ◽  
Desirable Outcome ◽  
Understory Plant ◽  
Future Condition

AbstractChinese privet is a major invasive shrub within riparian zones throughout the southeastern United States. We removed privet shrubs from four riparian forests in October 2005 with a Gyrotrac® mulching machine or by hand-felling with chainsaws and machetes to determine how well these treatments controlled privet and how they affected plant community recovery. One year after shrub removal a foliar application of 2% glyphosate was applied to privet remaining in the herbaceous layer. Three “desired-future-condition” plots were also measured to assess how well treatments shifted plant communities toward a desirable outcome. Both methods completely removed privet from the shrub layer without reducing nonprivet shrub cover and diversity below levels on the untreated control plots. Nonprivet plant cover on the mulched plots was > 60% by 2007, similar to the desired-future-condition plots and higher than the hand-felling plots. Both treatments resulted in higher nonprivet plant cover than the untreated controls. Ordination showed that after 2 yr privet removal plots were tightly grouped, suggesting that the two removal techniques resulted in the same plant communities, which were distinctly different from both the untreated controls and the desired-future-condition. Both treatments created open streamside forests usable for recreation and other human activities. However, much longer periods of time or active management of the understory plant communities, or both, will be required to change the forests to typical mature forest plant communities.

Effect of Aminopyralid on Canada Thistle (Cirsium arvense) and the Native Plant Community in a Restored Tallgrass Prairie

2010 ◽  
Vol 3 (2) ◽  
pp. 155-168 ◽  
Author(s):  
Travis L. Almquist ◽  
Rodney G. Lym
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Native Species ◽  
Cirsium Arvense ◽  
Grass Species ◽  
Stem Density ◽  
Native Plant ◽  
Canada Thistle ◽  
Native Plant Community ◽  
Restored Prairie

AbstractAminopyralid efficacy on Canada thistle (Cirsium arvense) and potential to injure native species was evaluated in a restored prairie at the Glacial Ridge Preserve managed by The Nature Conservancy in Polk County, MN. Canada thistle stem density was reduced from 17 to 0.1 stems m−2 10 mo after treatment (MAT) with aminopyralid applied in the fall at 120 g ha−1. Aminopyralid also altered the composition of both Canada thistle–infested and native plant communities. Aminopyralid controlled Canada thistle and removed or reduced several undesirable forb species from the restored prairie communities, such as absinth wormwood (Artemisia absinthium) and perennial sowthistle (Sonchus arvensis). A number of high seral forbs were also reduced or removed by aminopyralid, including maximilian sunflower (Helianthus maximiliani) and purple prairie clover (Dalea purpurea). Foliar cover of high seral forbs in the native plant community was reduced from 12.2 to 7% 22 MAT. The cover of high seral grass species, such as big bluestem (Andropogon gerardii) and Indiangrass (Sorghastrum nutans) increased after aminopyralid application in both the Canada thistle–infested and native plant communities and averaged 41.4% cover compared with only 19.4% before removal of Canada thistle. Species richness, evenness, and diversity were reduced after aminopyralid application in both Canada thistle–infested and native plant communities. However, the benefits of Canada thistle control, removal of undesirable species, and the increase in native grass cover should lead to an overall improvement in the long-term stability and composition of the restored prairie plant community, which likely outweigh the short-term effects of a Canada thistle control program.

Ecological Characteristics of Sites Invaded by Buffelgrass (Pennisetum ciliare)

2012 ◽  
Vol 5 (4) ◽  
pp. 443-453 ◽  
Author(s):  
Scott R. Abella ◽  
Lindsay P. Chiquoine ◽  
Dana M. Backer
Keyword(s):  
Seed Bank ◽  
Sonoran Desert ◽  
Native Species ◽  
Plant Cover ◽  
The United States ◽  
Slope Aspect ◽  
Plant Colonization ◽  
Native Plant ◽  
Organic C ◽  
Ecological Characteristics

AbstractUnderstanding the ecological characteristics of areas invaded and not invaded by exotic plants is a priority for invasive plant science and management. Buffelgrass is an invasive perennial species that managers view as a major threat to indigenous ecosystems of conservation lands in Australia, Mexico, the United States, and other locations where the species is not native. At 14 sites in Saguaro National Park in the Arizona Uplands of the Sonoran Desert, we compared the soil, vegetation, and soil seed bank of patches invaded and not invaded by buffelgrass. Abiotic variables, such as slope aspect and soil texture, did not differ between buffelgrass patches and patches without buffelgrass. In contrast, variables under primarily biotic control differed between patch types. Soil nutrients, such as organic C and NO3–N, were approximately twofold greater in buffelgrass compared with nonbuffelgrass patches. Average native species richness was identical (14 species 100 m−2) between patch types, but native plant cover was 43% lower in buffelgrass patches. Unexpectedly, native seed-bank densities did not differ significantly between patch types and were 40% greater than buffelgrass seed density below buffelgrass canopies. Results suggest that (1) soil nutrient status should not be unfavorable for native plant colonization at buffelgrass sites if buffelgrass is treated; (2) at least in the early stages of buffelgrass patch formation (studied patches were about 10 yr old), native vegetation species were not excluded, but rather, their cover was reduced; and (3) native soil seed banks were not reduced in buffelgrass patches.

scholarly journals Decoupled recovery of ecological communities after reclamation

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7038 ◽  
Author(s):  
Zachary A. Sylvain ◽  
David H. Branson ◽  
Tatyana A. Rand ◽  
Natalie M. West ◽  
Erin K. Espeland
Keyword(s):  
Plant Species ◽  
Plant Communities ◽  
Oil And Gas ◽  
Plant Cover ◽  
Reference Conditions ◽  
Soil Conditions ◽  
Ecological Communities ◽  
Native Plant ◽  
Ecosystem Recovery ◽  
Nematode Communities

Grassland restoration is largely focused on creating plant communities that match reference conditions. However, these communities reflect only a subset of the biodiversity of grassland systems. We conducted a multi-trophic study to assess ecosystem recovery following energy development for oil and gas extraction in northern US Great Plains rangelands. We compared soil factors, plant species composition and cover, and nematode trophic structuring between reclaimed oil and gas well sites (“reclaims”) that comprise a chronosequence of two—33 years since reclamation and adjacent, undeveloped rangeland at distances of 50 m and 150 m from reclaim edges. Soils and plant communities in reclaims did not match those on undeveloped rangeland even after 33 years. Reclaimed soils had higher salt concentrations and pH than undeveloped soils. Reclaims had lower overall plant cover, a greater proportion of exotic and ruderal plant cover and lower native plant species richness than undeveloped rangeland. However, nematode communities appear to have recovered following reclamation. Although total and omni-carnivorous nematode abundances differed between reclaimed well sites and undeveloped rangeland, community composition and structure did not. These findings suggest that current reclamation practices recover the functional composition of nematode communities, but not soil conditions or plant communities. Our results show that plant communities have failed to recover through reclamation: high soil salinity may create a persistent impediment to native plant growth and ecosystem recovery.

scholarly journals Native Plant Recovery following Three Years of Common Reed (Phragmites australis) Control

2018 ◽  
Vol 11 (4) ◽  
pp. 175-180 ◽  
Author(s):  
Christopher L. Zimmerman ◽  
Rebecca R. Shirer ◽  
Jeffrey D. Corbin
Keyword(s):  
Phragmites Australis ◽  
Native Species ◽  
Plant Cover ◽  
Management Strategies ◽  
Species Abundance ◽  
Common Reed ◽  
Exotic Plant ◽  
Native Plant ◽  
Native Community ◽  
Native Plant Community

AbstractProjects that aim to control invasive species often assume that a reduction of the target species will increase native species abundance. However, reports of the responses of native species following exotic species control are relatively rare. We assessed the recovery of the native community in five tidal wetland locations in which we attempted to eradicate the invasive common reed [Phragmites australis (Cav.) Trin. ex Steud.]. We tested whether 3 yr of treatment were able to eradicate Phragmites and promote recovery of the native plant community. After 3 yr of treatment, Phragmites density declined sharply in all treated stands, though it was not eradicated in any of them. Native plant cover increased significantly in treated areas, and community composition, particularly in smaller stands, converged toward that of uninvaded habitat. Thus, even within the relatively short timescale of the treatments and monitoring, significant progress was made toward achieving the goals of controlling Phragmites infestations and promoting native biodiversity. There was a trend toward greater promise for success in smaller stands than larger stands, as has been observed in other studies. A greater emphasis on monitoring whole-community responses to exotic plant control, across a range of conditions, would enhance our ability to plan and design successful management strategies.

scholarly journals Sowing Mixtures of Native Plant Species: Are There Any Differences between Hydroseeding and Regular Seeding?

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2507
Author(s):  
Vilma Gudyniene ◽  
Sigitas Juzenas ◽  
Vaclovas Stukonis ◽  
Egle Norkeviciene
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Native Species ◽  
Growth Traits ◽  
Plant Cover ◽  
Species Abundance ◽  
Legume Species ◽  
Competitive Growth ◽  
Native Plant ◽  
Native Plant Species

Hydroseeding is a convenient, low-cost way to plant seeds. Traditionally, fast-growing commercial species that are cheap to obtain are preferred in hydroseeding, while native species have limited use. Nowadays, the use of native species is often desired in revegetation projects. However, there is a paucity of information about hydroseeding native species in Northern areas of Europe. Therefore, we aimed to determine whether hydroseeding has any effects on native plant cover formation, species richness and abundance, the development of plant morphological features, or aboveground biomass. A total of 40 native plant species in Lithuania were sowed using hydroseeding and regular seeding. The experimental plots were assessed for two years. The results show a relatively small and short positive effect of hydroseeding on plant cover formation. No significant differences were found in species richness between the sowing treatments. However, a comparison of species composition revealed significant differences between the sowing treatments that were more associated with species abundance than species diversity. Hydroseeding was favoured by legume species, such as Onobrychis viciifolia, Ononis arvensis, Lotus corniculatus, and Trifolium medium, while Festuca rubra favoured the regular seeding treatment. Overall, our findings emphasize that legume species that display more competitive growth traits should be included in the seed mixture in lower proportions when hydroseeding is applied.

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