Dataset Information

Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola.

ABSTRACT: Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying the high abundance of H. manubrialis, cages with three types of naturally occurring litter with different nutrient content were placed out in the area and collected after different periods of time. Hypogastrura manubrialis was mainly found in the nutrient-rich litter of the yellowbush (Galenia africana), which responds positively to disturbance in the form of overgrazing. This suggests that invasion may have been facilitated by a positive interaction with this grazing resistant plant. By contrast, indigenous Collembola were least abundant in yellowbush litter. Negative correlations between high abundance of H. manubrialis and the abundance and diversity of other species suggest that competitive interactions might underlie low abundance of these other species at the patch level. Group behavior enables H. manubrialis to utilize efficiently this ephemeral, high quality resource, and might improve its competitive ability. The results suggest that interactions among environmental change drivers may lead to unforeseen invasion effects. H. manubrialis is not likely to be very successful in un-grazed renosterveld, but in combination with grazing, favoring the nutrient-rich yellowbush, it may become highly invasive. Field manipulations are required to fully verify these conclusions.

SUBMITTER: Leinaas HP

PROVIDER: S-EPMC4569040 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola.

Leinaas Hans Petter HP Bengtsson Jan J Janion-Scheepers Charlene C Chown Steven L SL

Ecology and evolution 20150725 16

Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying ...[more]

PMID: 26380678

Similar Datasets

Project description:In order to predict which species can successfully cope with global warming and how other environmental stressors modulate their vulnerability to climate-related environmental factors, an understanding of the ecophysiology underpinning thermal limits is essential for both conservation biology and invasion biology.Heat tolerance and the extent to which heat tolerance differed with oxygen availability were examined for four native and four alien freshwater peracarid crustacean species, with differences in habitat use across species. Three hypotheses were tested: (1) Heat and lack of oxygen synergistically reduce survival of species; (2) patterns in heat tolerance and the modulation thereof by oxygen differ between alien and native species and between species with different habitat use; (3) small animals can better tolerate heat than large animals, and this difference is more pronounced under hypoxia.To assess heat tolerances under different oxygen levels, animal survival was monitored in experimental chambers in which the water temperature was ramped up (0.25°C min-1). Heat tolerance (CTmax) was scored as the cessation of all pleopod movement, and heating trials were performed under hypoxia (5 kPa oxygen), normoxia (20 kPa) and hyperoxia (60 kPa).Heat tolerance differed across species as did the extent by which heat tolerance was affected by oxygen conditions. Heat-tolerant species, for example, Asellus aquaticus and Crangonyx pseudogracilis, showed little response to oxygen conditions in their CTmax, whereas the CTmax of heat-sensitive species, for example, Dikerogammarus villosus and Gammarus fossarum, was more plastic, being increased by hyperoxia and reduced by hypoxia.In contrast to other studies on crustaceans, alien species were not more heat-tolerant than native species. Instead, differences in heat tolerance were best explained by habitat use, with species from standing waters being heat tolerant and species from running waters being heat sensitive. In addition, larger animals displayed lower critical maximum temperature, but only under hypoxia. An analysis of data available in the literature on metabolic responses of the study species to temperature and oxygen conditions suggests that oxygen conformers and species whose oxygen demand rapidly increases with temperature (low activation energy) may be more heat sensitive.The alien species D. villosus appeared most susceptible to hypoxia and heat stress. This may explain why this species is very successful in colonizing new areas in littoral zones with rocky substrate which are well aerated due to continuous wave action generated by passing ships or prevailing winds. This species is less capable of spreading to other waters which are poorly oxygenated and where C. pseudogracilis is the more likely dominant alien species. A http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13050/suppinfo is available for this article.

Dataset Information

Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola.

Publications

Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets