Experimental removal of a dominant species at two levels of soil fertility

Gurevitch, Jessica; Unnasch, Robert S.

doi:10.1139/b89-424

Cited by 94 publications

(57 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When productivity and biomass are artificially increased through nutrient additions, species density consistently declines in a wide variety of habitats, including arctic tundra, old fields, grasslands, and other herbaceous communities (Bakelaar and Odum 1978, Silvertown 1980, Vermeer 1986, Gurevitch and Unnasch 1989, Carson and Pickett 1990, DiTommaso and Aarssen 1991, Wilson andTilman 1993, Chapin et al 1995; for an exception, see Goldberg and Miller 1990 result suggests a direct correlation between these two variables and supports the idea that, with increased biomass, competitive exclusion becomes more important in structuring the plant community.…”

Section: Introductionmentioning

confidence: 69%

Herbivore Effects on Plant Species Density at Varying Productivity Levels

Gough

Grace

1998

Ecology

View full text Add to dashboard Cite

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecology.Abstract. Artificially increasing primary productivity decreases plant species richness in many habitats; herbivory may affect this outcome, but it has rarely been directly addressed in fertilization studies. This experiment was conducted in two Louisiana coastal marshes to examine the effects of nutrient enrichment and sediment addition on herbaceous plant communities with and without vertebrate herbivory. After three growing seasons, fertilization increased community biomass in all plots, but decreased species density (the number of species per unit area) only in plots protected from herbivory. Herbivory alone did not alter species density at either site. At the brackish marsh, herbivory caused a shift in dominance in the fertilized plots from a species that is considered the competitive dominant, but is selectively eaten, to another less palatable species. At the fresh marsh, increased dead biomass in the absence of herbivory and in the fertilized plots probably contributed to the decrease in species density, perhaps by limiting germination of annuals. Our results support those of other fertilization studies in which plant species density decreases with increased biomass, but only in those plots protected from herbivory.

show abstract

Section: Introductionmentioning

confidence: 69%

Herbivore Effects on Plant Species Density at Varying Productivity Levels

Gough

Grace

1998

Ecology

View full text Add to dashboard Cite

show abstract

“…Removal experiments (e.g. Clements et al 1929;Fowler 1981;Gurevitch & Unnasch 1989) show that competition is a powerful force in the field. Probably there are too many obscuring factors for our SpeciesIdentity Retained biomass analysis to demonstrate it.…”

Section: Discussionmentioning

confidence: 99%

Community structure and assembly rules in a dune slack: Variance in richness, guild proportionality, biomass constancy and dominance/diversity relations

Wilson

Gitay

1995

Vegetatio

View full text Add to dashboard Cite

There is still disagreement as to whether plant communities can be described as conforming to certain assembly rules. We searched for such rules in the vegetation of four dune slacks in west Wales by examining variance in richness, guild proportionality, biomass constancy and dominance/diversity relations. To test for the occurrence of niche limitation, variance in quadrat species-richness was compared to null models of species occurrence. Using an Overall-model, one site showed a deficit of variance, but this disappeared when a Patch-model analysis was used. It therefore seems likely that the effect observed was due to equality in the species pools adapted to different microenvironments. The proportional representation of functional guilds was examined, in guilds based on morphology and life history. Significant constancy of guild proportions was seen for the annual guild in the only site in which it occurred, perhaps reflecting a regeneration niche. Total biomass per quadrat was examined, and compared to a model in which the biomass of each species was determined at random from the biomasses of that species at the site. Surprisingly, the observed biomasses showed no departure from the null model. However, there was considerable discrepancy from an alternative null model in which biomasses were allocated at random irrespective of species. This would imply that competition limits species coexistence, rather than performance. Examination of the proportions of species from different potential-size classes in each quadrat gave limited confirmation. The local abundance of species (mean biomass) was significantly correlated with the frequency of the species within a site, parallelling the geographical-range/local-abundance correlation previously reported. Five dominance/diversity models were fitted to the biomass data. The best fits were given by the Geometric or the General Lognormal models, though which fitted best varied between and within sites. Between sites, there was some indication of a consistent difference in Preston's 'gamma'. Most of the results are compatible with Gleason's Individualistic concept of the plant community, though there are several pointers that assembly rules have some impact on community structure.

show abstract

“…GOSE site managers speculate that the establishment of D. glomerata is facilitated by increased nitrogen availability as a consequence of broom invasion, and that this results in a decline in native plant species and a change in community structure. Fertilization experiments in oldfields with D. glomerata by Gurevitch and Unnasch (1989) demonstrated such a change in community structure.…”

Section: Introductionmentioning

confidence: 93%

Relationships between Scotch broom (Cytisus scoparius), soil nutrients, and plant diversity in the Garry oak savannah ecosystem

Shaben

Myers

2009

Plant Ecol

View full text Add to dashboard Cite

Scotch broom (Cytisus scoparius), is a leguminous shrub, native to the Mediterranean, which has invaded most of the remaining Garry oak savannah ecosystems in Oregon, Washington, and British Columbia. Here, it is considered to be a threat to the native plant community. We tested the hypothesis that broom would increase available soil nitrogen by comparing soil nutrients in contiguous broom-invaded and non-invaded sites. We then looked for changes in patterns of diversity in the herbaceous community that might indicate a role of Scotch broom in changing conditions following its invasion. Finally we carried out greenhouse assays to test whether broom had a greater impact on the growth of a native and an introduced grass compared to that of a native shrub. Broom was associated with only a weak trend in increased soil nitrogen, but a significant decrease in soil phosphorus was observed. Patterns of plant diversity differed between two sites. At one site, 60% of the plants whose abundances increased in the broom-invaded plots were introduced species while native species abundances decreased in the broominvaded plots compared to broom-free plots. At the other site, 60% of the plants that caused the differences between broom-invaded and un-invaded plots were native species that were less abundant in the broom-invaded plots. Finally, in greenhouse assays grass growth was not affected as a result of being grown with broom; however, grasses appeared to produce more flowers when grown with broom. We conclude that broom does not necessarily modify soil nitrogen availability but may deplete soil phosphorus availability and that broom invasion can be associated with increase of exotic species and/or the decline of native species.

show abstract

Experimental removal of a dominant species at two levels of soil fertility

Cited by 94 publications

References 0 publications

Herbivore Effects on Plant Species Density at Varying Productivity Levels

Herbivore Effects on Plant Species Density at Varying Productivity Levels

Community structure and assembly rules in a dune slack: Variance in richness, guild proportionality, biomass constancy and dominance/diversity relations

Relationships between Scotch broom (Cytisus scoparius), soil nutrients, and plant diversity in the Garry oak savannah ecosystem

Contact Info

Product

Resources

About