Understory responses to fire and artificial seeding in an eastern Cascades Abies grandis forest, U.S.A.

1999 ◽  
Vol 29 (9) ◽  
pp. 1393-1401 ◽  
Author(s):  
Tania L Schoennagel ◽  
Donald M Waller

To mitigate erosion after fire, land managers often seed non-native grasses onto burned slopes. To assess how post-fire seeding affects plant recovery, we compared areas that were either unseeded or artificially seeded after high-intensity fire in a dry Abies grandis (Dougl.) Lindl. forest in the northeastern Cascades. Seeding with a mix of non-native grasses and a legume significantly reduced the cover of native plants and shifted patterns of relative abundance after 2 years. Although seeding did not significantly affect total cover or native species richness, it reduced overall native plant cover by 47%. Species that recolonize via wind-dispersed seeds (e.g., Epilobium angustifolium L., Lactuca serriola L., and Arenaria macrophylla Hook.), species with long-lived seeds that germinate after fire (e.g., Ceanothus velutinus Dougl.), and species with wide successional amplitudes that resprout after fire (e.g., Apocynum androsaemifolium L. and Salix scouleriana Barratt) all declined steeply in cover on seeded plots. In addition, conifer seedlings were only half as abundant on seeded plots. As seeding after fire does not boost total plant cover and limits conifer tree establishment on the study area, it appears to do little to reduce the risk of soil erosion. It also appears to inhibit native shrub and herb re-establishment. These substantial effects on native species appear to alter plant communities well beyond the life of the seeded species.

2010 ◽  
Vol 19 (4) ◽  
pp. 490 ◽  
Author(s):  
Erich K. Dodson ◽  
David W. Peterson ◽  
Richy J. Harrod

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.


2012 ◽  
Vol 5 (4) ◽  
pp. 443-453 ◽  
Author(s):  
Scott R. Abella ◽  
Lindsay P. Chiquoine ◽  
Dana M. Backer

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.


2018 ◽  
Vol 11 (4) ◽  
pp. 175-180 ◽  
Author(s):  
Christopher L. Zimmerman ◽  
Rebecca R. Shirer ◽  
Jeffrey D. Corbin

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.


2013 ◽  
Vol 280 (1767) ◽  
pp. 20131446 ◽  
Author(s):  
Jake M. Alexander

A topic of great current interest is the capacity of populations to adapt genetically to rapidly changing climates, for example by evolving the timing of life-history events, but this is challenging to address experimentally. I use a plant invasion as a model system to tackle this question by combining molecular markers, a common garden experiment and climatic niche modelling. This approach reveals that non-native Lactuca serriola originates primarily from Europe, a climatic subset of its native range, with low rates of admixture from Asia. It has rapidly refilled its climatic niche in the new range, associated with the evolution of flowering phenology to produce clines along climate gradients that mirror those across the native range. Consequently, some non-native plants have evolved development times and grow under climates more extreme than those found in Europe, but not among populations from the native range as a whole. This suggests that many plant populations can adapt rapidly to changed climatic conditions that are already within the climatic niche space occupied by the species elsewhere in its range, but that evolution to conditions outside of this range is more difficult. These findings can also help to explain the prevalence of niche conservatism among non-native species.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2507
Author(s):  
Vilma Gudyniene ◽  
Sigitas Juzenas ◽  
Vaclovas Stukonis ◽  
Egle Norkeviciene

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.


2020 ◽  
Vol 12 (2) ◽  
pp. 454 ◽  
Author(s):  
Kinga Kostrakiewicz-Gierałt ◽  
Artur Pliszko ◽  
Katarzyna Gmyrek-Gołąb

Over the last decades, valuable natural areas considered as zones of silence and rest have been increasingly struggling with the problem of mass tourism. In this study, an investigation of the effect of visitors on the properties of vegetation of calcareous grasslands in the context of width and distances from tourist trails is performed. The study was conducted in seven localities in Cracow (southern Poland) involving calcareous grasslands impacted by tourist trails. The results show that the lower height of plants, the greater number of species and the greater percentage of plant cover damaged by trampling in plots located close to the edge of tourist trails, as well as lower total plant cover and greater mean cover-abundance degree per species along narrow pathways. The dominance of meadow and grassland species, as well as the prevalence of native species, suggests that the composition of the examined vegetation has not been drastically changed. In the majority of the study plots, the dominance of hemicryptophytes and chamaephytes, inconsiderable share of phanerophytes and therophytes, as well as the low share of geophytes, were observed. The infrequent occurrence of species presenting Bidens dispersal type along narrow pathways, as well as in plots located close to the edge of tourist trails, suggests low external transport of epizoochorous seeds by passing people, while the prevalence of species presenting Cornus type in plots located away from the edge of tourist trails might be the effect of dung deposition by animals.


2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Chaeho Byun ◽  
Ho Choi ◽  
Hojeong Kang

Abstract Background Ambrosia trifida is a highly invasive annual plant, but effective control methods have not been proposed. Among various eradication methods, cutting is a simple measure to control invasive plants, and sowing seeds of native plants may effectively increase biotic resistance to invasion. In this study, we conducted a field experiment with two treatments: cutting and sowing seeds of six native or naturalized plants. Results We found a significantly lower A. trifida abundance after cutting than in the control (77% decrease). Sowing seeds of native species did not provide any additional benefit for the control of A. trifida, but increased the importance values and diversity of other native vegetation. The abundance of A. trifida was negatively correlated with that of other plant taxa based on plant cover, biomass, and density. However, biotic resistance of sown plants was not effective to control invasion because A. trifida was so competitive. Conclusions We concluded that cutting is an effective measure to control Ambrosia trifida while sowing seeds of native plants can increase native plant diversity.


2016 ◽  
pp. 28-36 ◽  
Author(s):  
Ya. M. Golovanov ◽  
L. M. Abramova

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.


2010 ◽  
Vol 19 (6) ◽  
pp. 746 ◽  
Author(s):  
Ken A. Stella ◽  
Carolyn H. Sieg ◽  
Pete Z. Fulé

The rationale for seeding following high-severity wildfires is to enhance plant cover and reduce bare ground, thus decreasing the potential for soil erosion and non-native plant invasion. However, experimental tests of the effectiveness of seeding in meeting these objectives in forests are lacking. We conducted three experimental studies of the effectiveness of seeding with non-native and native species following three Arizona wildfires. Seeding treatments were largely ineffective in increasing vegetative cover or decreasing exposed bare ground. At one treatment at one fire, wheat seeding at the Warm Fire, senesced seeded annuals increased litter cover and resulted in lower bare ground values than unseeded controls. Only on one fire, the Warm Fire, did seeded non-native annuals establish well, resulting in 20–29% vegetative cover. On the other two fires, seeded cereal grains accounted for <3% cover. At all fires, native seeded species contributed between <1 and ∼12% vegetative cover. Vegetative cover on all treatments, including unseeded treatments, was at or near 40% the first year following fire, at all three study sites. Non-native species richness and abundance did not differ among treatments at any fire. This study adds to growing evidence that post-fire seeding is ineffective in enhancing post-fire plant cover and reducing invasive non-native plants.


2018 ◽  
Author(s):  
Andrew O'Reilly-Nugent ◽  
Elizabeth Wandrag ◽  
Jane Catford ◽  
Bernd Gruber ◽  
Don Driscoll ◽  
...  

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.


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