Impacts and Best Management Practices for Erect Veldtgrass (Ehrharta erecta)

2018 ◽  
Vol 11 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Courtenay A. Ray ◽  
Joel J. Sherman ◽  
Anna L. Godinho ◽  
Nikki Hanson ◽  
Ingrid M. Parker
Keyword(s):  
Species Richness ◽  
Best Management Practices ◽  
Native Species ◽  
Management Practices ◽  
Native Plants ◽  
Forest Understory ◽  
Evergreen Forest ◽  
Percent Cover ◽  
Native Plant ◽  
Optimal Method

AbstractErect veldtgrass (Ehrharta erecta Lam.) is an invasive grass actively spreading in California that is capable of invading multiple habitats. Our objective is to contribute to a better understanding of the ecology, impacts, and potential for control of E. erecta in order to guide management practices. In a mixed-evergreen forest in Santa Cruz County, we measured impacts of E. erecta on native plant species richness and abundance in an observational comparison across 11 sites. Strikingly, we measured nearly four times greater total vegetation cover in plots invaded by E. erecta. However, native plants were not significantly less abundant in invaded plots than in reference plots, and native cover was not significantly predicted by E. erecta cover within invaded plots. We did, however, find evidence of change in community composition in response to E. erecta abundance. Our findings demonstrate that native species can persist in the presence of E. erecta, although the long-term impacts on populations of the perennial plants that dominate this forest understory are still unknown.We also compared the effectiveness of mechanical (hand pulling with volunteers) and chemical (glyphosate) management methods. Twenty-two months following management treatments, we found substantial reductions in E. erecta using both mechanical and herbicide treatments, but herbicide application also produced greater reductions in native species cover and species richness. Transplanting native yerba buena [Clinopodium douglasii (Benth.) Kuntze] into management plots following treatment did not slow regrowth of E. erecta. It did, however, increase total native plant percent cover in herbicide and pull treatments, although largely by increasing C. douglasii cover. Effective management is possible using either manual or chemical removal methods; the optimal method may depend on the availability of manual labor and the sensitivity of the habitat to non-target effects on native plants.

scholarly journals Native plant and weed diversity in forest remnants affected by Tradescantia fluminensis management

2012 ◽  
Vol 65 ◽  
pp. 74-80
Author(s):  
C.S. Lusk ◽  
G.A. Hurrell ◽  
S.L. Lamoureaux
Keyword(s):  
Weed Management ◽  
Native Species ◽  
Management Practices ◽  
Percent Cover ◽  
Native Plant ◽  
Forest Remnants ◽  
Weed Diversity ◽  
Line Transects ◽  
Tradescantia Fluminensis ◽  
Plant Seedlings

This study aimed to determine the effects of different management practices for Tradescantia fluminensis in lowland podocarp/broadleaf forest remnants in the lower North Island Fourteen 50 m line transects across eight sites were established in April 2009 and assessed annually until 2012 Management practices prior to and during the study period were documented Over the four assessments changes in the numbers of native plant seedlings and species differed greatly between management practices as did the percent cover of Tradescantia and other weeds Native species diversity improved more and the abundance of Tradescantia and other weeds increased less in forests that were less disturbed and where careful ongoing control was carried out than in forests with more disturbance prior to or during control operations Effective monitoring of both weeds and native plants is essential to enable the outcome of weed management practices to be measured

SGS Biodiversity Theme: impact of plant biodiversity on the productivity and stability of grazing systems across southern Australia

2003 ◽  
Vol 43 (8) ◽  
pp. 961 ◽  
Author(s):  
D. R. Kemp ◽  
W. McG. King ◽  
A. R. Gilmour ◽  
G. M. Lodge ◽  
S. R. Murphy ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Plant Species ◽  
Native Species ◽  
Management Practices ◽  
Plant Species Diversity ◽  
Native Plant ◽  
Total Species Richness ◽  
Grazing Systems ◽  
Sustainable Grazing

The relationships between productivity and plant species diversity were assessed using data from the Sustainable Grazing Systems (SGS) 10 national experiment sites. Each site applied up to 7 different management treatments. Sites varied in the amount of data available for analysis. Plant species diversity was assessed in terms of both the total and native species present at each site. More than 200 plant taxa were recorded over the period of the experiment, about one-third of which were native. In the majority of cases, the native species present within a treatment remained there throughout the experiments, even when fertilised and oversown with introduced species. The number of native species increased by 1 or 2 over the 3–4 years of each experiment where grasslands were less intensively used (average herbage mass >2 t DM/ha), but decreased in more heavily grazed treatments. Native grasses made much greater contributions to herbage mass than other native species. Of the more than 70 native plant species found, the most numerous were broadleaf species, which tended to be more variable under management treatments. As total species richness increased, there was a tendency for pasture productivity to be less, for the mean standing herbage mass to be less and for seasonal growth to be less stable. This depended upon experiments and tended to apply at the sites with higher annual pasture growth rates. All treatments had >10 plant species within the small (about 1.5 ha) paddocks used and larger paddocks often had many more. It was apparent from the high plant species richness at each site (about 25–100 species) that many more niches exist in these paddocks than the number of species usually sown in a pasture. Opportunities to redesign pasture mixtures to exploit more of the resources available obviously exist. Understanding of the relationships among management practices, productivity and plant species diversity is limited, but will become important as we seek more sustainable grazing systems. The studies analysed here suggested that where the herbage mass was maintained between 2 and 4 t DM/ha then species were maintained and productivity was optimised.

Seed dispersal interactions promoting plant invasions.

2020 ◽  
pp. 90-104
Author(s):  
M. Celeste Díaz Vélez ◽  
Ana E. Ferreras ◽  
Valeria Paiaro
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Seedling Establishment ◽  
Native Species ◽  
Native Plants ◽  
Woody Species ◽  
Native Plant ◽  
Invasional Meltdown ◽  
Native Plant Species ◽  
Origin Life

Abstract Animal dispersers are essential for many non-native plants since they facilitate seed movement and might promote seed germination and seedling establishment, thereby increasing their chances of invasion. This chapter reviews the published literature on seed dispersal of non-native plant species by native and/or non-native animals. The following questions are addressed: (i) Are interactions between non-native plants and their animal dispersers evenly studied worldwide? (ii) Which are the distinctive traits (i.e. geographical origin, life form, dispersal strategy and propagule traits) of non-native plants that are dispersed by animals? (iii) Which are the most studied groups of dispersers of non-native plants around the world? (iv) Does the literature provide evidence for the Invasional Meltdown Hypothesis (non-native plant-non-native disperser facilitation)? (v) What is the role of animal dispersers at different stages of the non-native plant regeneration process? Our dataset of 204 articles indicates that geographical distribution of the studies was highly heterogeneous among continents, with the highest number coming from North America and the lowest from Asia and Central America. Most of the non-native plants involved in dispersal studies were woody species from Asia with fleshy fruits dispersed by endozoochory. More than the half of the animal dispersal agents noted were birds, followed by mammals, ants and reptiles. The dominance of bird-dispersal interactions over other animal groups was consistent across geographical regions. Although most of the studies involved only native dispersers, interactions among non-native species were detected, providing support for the existence of invasional meltdown processes. Of the total number of reviewed articles reporting seed removal, 74% evaluated seed dispersal, but only a few studies included seed germination (35.3%), seedling establishment (5.4%) or seed predation (23.5%). Finally, we discuss some research biases and directions for future studies in the area.

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.

scholarly journals Tallgrass Prairie Responses to Management Practices and Disturbances: A Review

Agronomy ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 300 ◽  
Author(s):  
Pradeep Wagle ◽  
Prasanna Gowda
Keyword(s):  
Species Richness ◽  
Soil Quality ◽  
Plant Species ◽  
Tallgrass Prairie ◽  
Management Practices ◽  
The United States ◽  
N Fertilization ◽  
Native Plant ◽  
The Impact

Adoption of better management practices is crucial to lessen the impact of anthropogenic disturbances on tallgrass prairie systems that contribute heavily for livestock production in several states of the United States. This article reviews the impacts of different common management practices and disturbances (e.g., fertilization, grazing, burning) and tallgrass prairie restoration on plant growth and development, plant species composition, water and nutrient cycles, and microbial activities in tallgrass prairie. Although nitrogen (N) fertilization increases aboveground productivity of prairie systems, several factors greatly influence the range of stimulation across sites. For example, response to N fertilization was more evident on frequently or annually burnt sites (N limiting) than infrequently burnt and unburnt sites (light limiting). Frequent burning increased density of C4 grasses and decreased plant species richness and diversity, while plant diversity was maximized under infrequent burning and grazing. Grazing increased diversity and richness of native plant species by reducing aboveground biomass of dominant grasses and increasing light availability for other species. Restored prairies showed lower levels of species richness and soil quality compared to native remnants. Infrequent burning, regular grazing, and additional inputs can promote species richness and soil quality in restored prairies. However, this literature review indicated that all prairie systems might not show similar responses to treatments as the response might be influenced by another treatment, timing of treatments, and duration of treatments (i.e., short-term vs. long-term). Thus, it is necessary to examine the long-term responses of tallgrass prairie systems to main and interacting effects of combination of management practices under diverse plant community and climatic conditions for a holistic assessment.

Exotic plant invasion and understorey species richness: a comparison of two types of eucalypt woodland in agricultural Western Australia

1998 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Max Abensperg-Traun ◽  
Lyn Atkins ◽  
Richard Hobbs ◽  
Dion Steven
Keyword(s):  
Species Richness ◽  
Exotic Species ◽  
Plant Species ◽  
Plant Invasion ◽  
Native Plants ◽  
Exotic Plants ◽  
Exotic Plant ◽  
Native Plant ◽  
Road Verge ◽  
Exotic Plant Invasion

Exotic plants are a major threat to native plant diversity in Australia yet a generic model of the invasion of Australian ecosystems by exotic species is lacking because invasion levels differ with vegetation/soil type and environmental conditions. This study compared relative differences in exotic species invasion (percent cover, spp. richness) and the species richness of herbaceous native plants in two structurally very similar vegetation types, Gimlet Eucalyptus salubris and Wandoo E. capillosa woodlands in the Western Australian wheatbelt. For each woodland type, plant variables were measured for relatively undisturbed woodlands, woodlands with >30 years of livestock grazing history, and woodlands in road-verges. Grazed and road-verge Gimlet and Wandoo woodlands had significantly higher cover of exotic species, and lower species richness of native plants, compared with undisturbed Gimlet and Wandoo. Exotic plant invasion was significantly greater in Gimlet woodlands for both grazed (mean 78% cover) and road-verge sites (mean 42% cover) than in comparable sites in Wandoo woodlands (grazed sites 25% cover, road-verge sites 19% cover). There was no significant difference in the species richness of exotic plants between Wandoo and Gimlet sites for any of the three situations. Mean site richness of native plants was not significantly different between undisturbed Wandoo and undisturbed Gimlet woodlands. Undisturbed woodlands were significantly richer in plant species than grazed and road-verge woodlands for both woodland types. Grazed and road-verge Wandoo sites were significantly richer in plant species than communities in grazed and road-verge Gimlet. The percent cover of exotics was negatively correlated with total (native) plant species richness for both woodland types (Wandoo r = ?0.70, Gimlet r = ?0.87). Of the total native species recorded in undisturbed Gimlet, 83% and 61% were not recorded in grazed and road-verge Gimlet, respectively. This compared with 40% and 33% for grazed and road-verge Wandoo, respectively. Grazed Wandoo and grazed Gimlet sites had significantly fewer native plant species than did road-verge Wandoo and road-verge Gimlet sites. Ecosystem implications of differential invasions by exotic species, and the effects of grazing (disturbance) and other factors influencing susceptibility to exotic plant invasion (landscape, competition and allelopathy) on native species decline are discussed. Exclusion of livestock and adequate methods of control and prevention of further invasions by exotic plants are essential requirements for the conservation of these woodland systems.

Assessing the invasion threat of non-native plant species in protected areas using Herbarium specimen and ecological survey data. A case study in two rangeland bioregions in Queensland

2017 ◽  
Vol 39 (1) ◽  
pp. 85
Author(s):  
Michael R. Ngugi ◽  
Victor John Neldner
Keyword(s):  
Protected Areas ◽  
Survey Data ◽  
Native Species ◽  
Native Plants ◽  
Herbarium Specimen ◽  
Native Plant ◽  
Economic Productivity ◽  
Ecological Survey ◽  
National Significance

Naturalised non-native plants that become invasive pose a significant threat to the conservation of biodiversity in protected areas (areas dedicated and managed for long-term conservation of nature), economic productivity of agricultural businesses, and societal impacts including community, culture infrastructure and health. Quantifying the spread, potential dominance and invasion threat of these species is fundamental to effective eradication and development of threat mitigation policy. But this is often hampered by the lack of comprehensive data. This study used existing ecological survey data from 2548 sites and 64 758 Herbarium specimen records to document the status and abundance of non-native plants in two case study bioregions, Cape York Peninsula (CYP) and the Desert Uplands (DEU) in Queensland covering a total area of 186 697 km2. There were 406 non-native species in the CYP, 186 (45.6%) of which are known environmental weeds and 159 non-natives in DEU, of which 69 (43.5%) are environmental weeds. Inside the protected areas, there were 98 species of environmental weeds in CYP, 27 of which are listed as weeds of State significance (Weeds of National Significance (WONS), Queensland declared and non-declared pest plants categories). In DEU, there were 18 environmental weeds inside protected areas and none of them was listed as a weed of State significance. Non-native species that recorded foliage cover dominance in the ecological site data are generally recognised as environmental weeds in Queensland. The threat of weeds from outside of protected areas was serious, with 41 weeds of State significance found in CYP, five of which are WONS, and 25 weeds of State significance found in DEU, 10 of which are WONS.

scholarly journals Tests of Hexazinone and Tebuthiuron for Control of Exotic Plants in Kauai, Hawaii

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 576
Author(s):  
Wang ◽  
Awaya ◽  
Zhu ◽  
Motooka ◽  
Nelson ◽  
...  
Keyword(s):  
Invasive Plants ◽  
Loblolly Pine ◽  
Native Species ◽  
Native Plants ◽  
Early Period ◽  
Metrosideros Polymorpha ◽  
Native Plant ◽  
Weed Species ◽  
Invasive Weed ◽  
Native Plant Species

Non-native plant species have become serious pests in Hawaii’s delicate island ecosystems. It is necessary to control invasive plants. The herbicides hexazinone and tebuthiuron were evaluated for defoliation efficacy to control several major invasive plants and for non-target effects on native plants at Site I in a rainforest at 1200 m elevation and Site II in a mesic area at 640 m elevation on the island of Kauai, Hawaii. The invasive weed species in the sites included daisy fleabane (Erigeron karvinskianus DC.), faya tree (Myrica faya Ait.), strawberry guava (Psidium cattleyanum Sabine), banana passion fruit (Passiflora mollissima Bailey), vaseygrass (Paspalum urvillei Steud.), and highbush blackberry (Rubus argutus Link. 1822). Native plants included ohia lehua (Metrosideros polymorpha Gaudich.), naupaka (Scaevola cerasifolia Labill.), pilo (Hedyotis mannii), hona (Urera glabra (Hook. & Arn.)), aalii (Dodonaea viscosa Jacq.), and amau (Sadleria sp.). The results showed that broadcast applications of hexazinone granules and tebuthiuron pellets were effective on some of those invasive species. Herbicidal tolerance varied among the native species. For example, D. viscosa showed high tolerance to hexazinone. S. cerasifolia was susceptible to hexazinone, but not to tebuthiuron. The inconsistent defoliation of Sadleria sp. occurred among different applications rates of the two herbicides. M. polymorpha, particularly when it was small, could tolerate hexazinone and tebuthiuron. U. glabra was severely injured by the two herbicides. H. mannii was moderately tolerant to hexazinone, but fairly sensitive to tebuthiuron. The invasive loblolly pine (Pinus taeda L.) was highly tolerant to hexazinone, but was very sensitive to tebuthiuron. M. faya was very sensitive to hexazinone, but very tolerant to tebuthiuron. P. cattleyanum was sensitive to both herbicides. Six and nine months after hexazinone and tebuthiuron treatment, respectively, native plants were transplanted into the Sites to observe injury from residual herbicides. Approximately less than 10% mortality was observed for the out-planted native species three months after planting (MAP), indicating that the native species showed less injury in the early period of transplant. The mortality of the three endangered species Kauai hau kuahiwi (Hibiscadelphis distans), Kauai delissea (Delissea rhytidosperma H.Mann) and kawawaenohu (Alsinidendron lynchnoides), however, increased as the MAP increased. Overall, broadcast treatments of hexazinone and tebuthiuron at rates higher than 1 kg active ingredient per hectare would be problematic. The dissipation half-life values of hexazinone and tebuthiuron in the 1-15 cm layer of soils at the two sites were approximately 7 days and greater than 180 days, respectively.

Native plant species richness on Eastern Polynesia’s remote atolls

2015 ◽  
Vol 40 (1) ◽  
pp. 112-134 ◽  
Author(s):  
Sébastien Larrue ◽  
Jean-François Butaud ◽  
Pascal Dumas ◽  
Stéphane Ballet
Keyword(s):  
Species Richness ◽  
Sea Level ◽  
Plant Species ◽  
Native Species ◽  
Abiotic Factors ◽  
Plant Species Richness ◽  
Native Plant ◽  
Volcanic Island ◽  
Native Plant Species ◽  
Native Species Richness

Which abiotic factors influence the number of native plant species on remote atolls is an important question to understand better the spatial pattern of the species observed on these low and vulnerable coral islands. However, this issue is still very poorly documented, often due to human degradation, partial botanical surveys or the difficult geographic access of remote atolls for researchers. The remote atolls of Eastern Polynesia, which are among the most isolated in the world, are of great interest for studies of native species’ distribution due to their isolation, low human density and urbanisation. In this study, we selected 49 remote atolls of Eastern Polynesia with complete botanical surveys to test the relative influence of eight abiotic factors on native plant species richness (i.e. indigenous and endemic species). Abiotic factors used as potential predictors included atoll area (km2), shoreline length (km), atoll elevation (m) and index of isolation (UNEP), but also the coastal index of the atoll ( Ic), the distance to the nearest similar atoll (km), the distance to the nearest large volcanic island ≥ 1000 km2 (here, Tahiti as a potential stepping-stone island) and the distance to the nearest raised atoll ≥ 15 m a.s.l. (here, Makatea or Henderson as a potential refugium during sea-level highstands). Spearman’s rank correlation, linear regression analysis and frequency diagrams were used to assess the relative influence of these factors on native species richness. No relationship was found between the species richness and the index of isolation or the distance to the nearest similar atoll. Atoll area and distance to the nearest raised atoll of Makatea explained 47.1% and 40%, respectively, of the native species richness variation observed on the remote atolls. The distance to the volcanic island of Tahiti and the coastal index explained 36.9% and 27.3% of the variation, while elevation and shoreline length explained 23.3% and 18.4% of the variation, respectively. Native species richness on the atolls surveyed increased with the increasing atoll area, elevation and shoreline length, but decreased with the increasing distance to the nearest raised atoll of Makatea and the large volcanic island of Tahiti. This supports the view that the spatial pattern of native species richness observed on the remote atolls was strongly influenced by (i) atoll area but also by (ii) the distance to the raised atoll of Makatea, and (iii) the distance to the volcanic island of Tahiti. This finding suggests that the raised atoll may be viewed as a refugium during sea-level highstands while the large volcanic island played the role of stepping-stone island, both islands influencing the dispersal of native species on remote atolls and attenuating the isolation effect in the study area.

Vegetation change in an urban grassy woodland 1974 - 2000

2004 ◽  
Vol 52 (5) ◽  
pp. 597 ◽  
Author(s):  
J. B. Kirkpatrick
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Exotic Species ◽  
Native Species ◽  
Vegetation Change ◽  
Structural Changes ◽  
Linear Models ◽  
Tree Cover ◽  
Native Plant ◽  
Native Species Richness

Few temporal studies document vegetation change in Australian temperate grassy woodlands. Floristic and structural data were collected from 68 randomly located sites in the Queens Domain, an urban grassy woodland remnant, in 1974, 1984, 1994 and 2000 and a search made for rare species. Species of conservation significance were concentrated at highly disturbed sites, whereas vegetation types of conservation significance decreased in area as a result of increases in the numbers of Allocasuarina verticillata, which caused a change in many unmown areas from Eucalyptus viminalis grassy woodland to E. viminalis–A. verticillata woodland/forest or A. verticillata open/closed forest. Structural changes were associated with changes in species composition and an increase in native-species richness. Increases in tree cover occurred where fires were most frequent, possibly as a result of the lack of mammalian herbivores. The frequencies of herbs and annual grasses were strongly affected by precipitation in the month of sampling. Half of the species that showed a consistent rise or fall through time were woody plants, approximately twice the number expected. In the dataset as a whole, species-richness variables were largely explained by varying combinations of variables related to moisture availability, altitude and the incidence of mowing. The strongest influences on species composition were the same, although slope and time since the last fire also contributed to multiple regression and generalised linear models. Compositional stability was positively related to native-species richness, whereas high levels of exotic-species richness occurred at both low and high levels of native-species richness. The maintenance of native-plant biodiversity on the Domain requires such counterintuitive measures as the maintenance of exotic trees and the control of native trees, demonstrating the contingencies of conservation management in fragmented vegetation that consists of a mixture of native and exotic species.

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