Gap Colonization as a Source of Grassland Community Change: Effects of Gap Size and Grazing on the Rate and Mode of Colonization by Different Species

Bullock, James M.; Hill, B. Clear; Silvertown, Jonathan; Sutton, Martin John

doi:10.2307/3546229

Cited by 178 publications

(164 citation statements)

References 27 publications

Supporting

Mentioning

146

Contrasting

Unclassified

Order By: Relevance

“…In contrast with forest vegetation where most gap colonists are of seed origin (BROKAW & BUSING 2000), colonists of gaps in perennial grasslands can be of seed or clonal origin (BULLOCK et al 1995). The proportion of seed-derived and clonal colonists varies with gap size.…”

Section: Introductionmentioning

confidence: 99%

“…In perennials grasslands rapid vegetative spread (KOTANEN 1997, MARIOTT et al 1997) and smaller seed mass (KALAMEES & ZOBEL 2002, SUDING et al 2003 generally characterize gap colonizers. Consequently, plant species often occur with different relative frequencies in recently colonized gaps than they do in the surrounding vegetation (MARTINSEN et al 1990, BULLOCK et al 1995. This gap colonization is potentially an important source of vegetation change in grassland.…”

Section: Introductionmentioning

confidence: 99%

“…The proportion of seed-derived and clonal colonists varies with gap size. Increased gap size increases the density and size of seed-derived plants (BULLOCK et al 1995, ROGERS & HARTNETT 2001, VANDVIK 2004. The high proportion of species with clonal reproduction in grasslands (KLIMEŠ et al 1997, TAMM et al 2002 allows adult plants to colonize gaps.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of cattle activities on gap colonization in mountain pastures

et al. 2006

View full text Add to dashboard Cite

Cattle influences gap dynamics in pastures in two ways: (1) by creating gaps and (2) by affecting the colonization process. This effect of cattle activity on gap revegetation can be subdivided in three main factors: herbage removal, trampling and dung and urine deposition. The objective of this study was to assess how these three effects moderate the plant succession following gap creation.In an exclosure, four controlled treatments simulating cattle activity (repeated mowing, trampling, manuring and untreated control) were applied on plots of 2´2 m. In the centre of each plot, one artificial gap of 606 0 cm was created. During three years, vegetation changes were monitored in spring and in autumn, with a square grid of 100 cells of 0.01 m 2 centred on the gap. Our experiment confirmed that fine-scale gap creation may have a high impact on relative abundances of species in the community. The gap environment acts on species as a filter and this filtering was described in terms of regenerative attributes. Colonizers were species with small seeds, unspecialized seed dispersal, persistent seed bank and high vegetation spread. However, the role of dung deposition, herbage removal or trampling by cattle did not seem to be of primary importance in the revegetation process, but could moderate vegetation response. Therefore, the different cattle effects act as secondary filters that selectively favoured or disadvantaged different species from the gap-regenerating community. These complex interactions are probably keys to understand plant coexistence in perennial grasslands.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of cattle activities on gap colonization in mountain pastures

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Seed germination and early life stages are typically suppressed by higher water salinities and by daily inundation, and only those able to tolerate these harsh physical conditions can become established as seedlings. The clonal life-history strategy for reinvasion of gaps has been important in other systems (e.g., [61][62][63]). We observed that clonal species from the surrounding habitat dominated our newly-opened patches created by pepperweed elimination.…”

Section: Discussionmentioning

confidence: 99%

Invasion Age and Invader Removal Alter Species Cover and Composition at the Suisun Tidal Marsh, California, USA

Estrella

Kneitel

2011

Diversity

View full text Add to dashboard Cite

Abstract:Wetland ecosystems are vulnerable to plant species invasions, which can greatly alter species composition and ecosystem functioning. The response of these communities to restoration can vary following invader removal, but few studies have evaluated how recent and long-term invasions can affect the plant community's restoration potential. Perennial pepperweed (Lepidium latifolium) has invaded thousands of hectares of marshland in the San Francisco Estuary, California, United States of America, while the effects of invasion and removal of this weed remain poorly studied. In this study, perennial pepperweed was removed along a gradient of invasion age in brackish tidal marshes of Suisun Marsh, within the Estuary. In removal plots, resident plant cover significantly increased during the 2-year study period, particularly in the densest and oldest parts of the perennial pepperweed colonies, while species richness did not change significantly. In bare areas created by removal of perennial pepperweed, recolonization was dominated by threesquare bulrush (Schoenoplectus americanus). Ultimately, removal of invasive perennial pepperweed led to reinvasion of the resident plant community within two years. This study illustrates that it is important to consider invasion age, along with exotic species removal, when developing a restoration strategy in wetland ecosystems.

show abstract

“…Among those seed mechanisms, predation is one of the major causes of species composition of eastern deciduous forests and fields (Myster 1993). On the basis of studies in similar forest/grass areas, sources of variation in the working of seed predation that warrant investigation include: (1) increased predation by litter sheltering predators (Reader 1990;Aguilera & Lauenroth 1995;Bullock et al 1995), (2) different predators having different seed preferences (Myster & Pickett 1993), (3) different seed densities leading to different predator responses (Myster & Pickett 1993), (4) different seasons of the year and different years eliciting different predator responses (Lindroth & Batzli 1984), and (5) predation levels differing among microsites (Collins & Adams 1983;Collins & Uno 1985;Knapp et al 1998).…”

Section: Introductionmentioning

confidence: 99%

The role of seed predation in the maintenance of the Cross Timbers ecotone of Oklahoma, USA

Myster

2013

Journal of Plant Interactions

View full text Add to dashboard Cite

I investigated how seed predation differed among tree species and among microhabitats across the Cross Timbers and what that variation may tell us about how this ecotone is maintained. The ecotone is located in Oklahoma, USA, between the eastern deciduous forest and tallgrass prairie where seeds of eight common tree species were placed in three microhabitats (oak forest, tallgrass prairie, and sumac shrub/small-tree/grass mix). After nine days in the field, percent seeds remaining were scored for each of the 120 (8 species )3 microhabitats )5 replicates) dishes. I found for both wind-dispersed tree species, (ash, elm) there was significantly more predation in the prairie microsite, with similar small predation levels in the shrub and forest. For two of the three bird-dispersed species (dogwood, hackberry), there was significantly more predation in the prairie and shrub microsites compared to the forest. Red cedar, however, was not taken by predators very much anywhere. Finally, all three mammal-dispersed tree species (two oaks, pecan) showed significantly more predation in the shrub and forest microsites compared to the prairie. Whereas wind-and bird-dispersed species suffered less predation as microsites became more woody and dark, the dominant oaks showed the opposite trend. Consequently, seed predators are not preventing oaks from advancing across this ecotone, but yearly fluctuations in predator population density, especially in the shrub transitional zone, could be helping to maintain it.

show abstract

Gap Colonization as a Source of Grassland Community Change: Effects of Gap Size and Grazing on the Rate and Mode of Colonization by Different Species

Cited by 178 publications

References 27 publications

Effect of cattle activities on gap colonization in mountain pastures

Effect of cattle activities on gap colonization in mountain pastures

Invasion Age and Invader Removal Alter Species Cover and Composition at the Suisun Tidal Marsh, California, USA

The role of seed predation in the maintenance of the Cross Timbers ecotone of Oklahoma, USA

Contact Info

Product

Resources

About