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Effects of extreme climatic events on small-scale spatial patterns: a 20-year study of the distribution of a desert spider.

Birkhofer, Klaus LU ; Henschel, Joh and Lubin, Yael (2012) In Oecologia 170(3). p.651-657
Abstract
Individuals of most animal species are non-randomly distributed in space. Extreme climatic events are often ignored as potential drivers of distribution patterns, and the role of such events is difficult to assess. Seothyra henscheli (Araneae, Eresidae) is a sedentary spider found in the Namib dunes in Namibia. The spider constructs a sticky-edged silk web on the sand surface, connected to a vertical, silk-lined burrow. Above-ground web structures can be damaged by strong winds or heavy rainfall, and during dispersal spiders are susceptible to environmental extremes. Locations of burrows were mapped in three field sites in 16 out of 20 years from 1987 to 2007, and these grid-based data were used to identify the relationship between spatial... (More)
Individuals of most animal species are non-randomly distributed in space. Extreme climatic events are often ignored as potential drivers of distribution patterns, and the role of such events is difficult to assess. Seothyra henscheli (Araneae, Eresidae) is a sedentary spider found in the Namib dunes in Namibia. The spider constructs a sticky-edged silk web on the sand surface, connected to a vertical, silk-lined burrow. Above-ground web structures can be damaged by strong winds or heavy rainfall, and during dispersal spiders are susceptible to environmental extremes. Locations of burrows were mapped in three field sites in 16 out of 20 years from 1987 to 2007, and these grid-based data were used to identify the relationship between spatial patterns, climatic extremes and sampling year. According to Morisita's index, individuals had an aggregated distribution in most years and field sites, and Geary's C suggests clustering up to scales of 2 m. Individuals were more aggregated in years with high maximum wind speed and low annual precipitation. Our results suggest that clustering is a temporally stable property of populations that holds even under fluctuating burrow densities. Climatic extremes, however, affect the intensity of clustering behaviour: individuals seem to be better protected in field sites with many conspecific neighbours. We suggest that burrow-site selection is driven at least partly by conspecific cuing, and this behaviour may protect populations from collapse during extreme climatic events. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aggregation, Araneae, Climate, Conspecific cuing, Spatial analysis
in
Oecologia
volume
170
issue
3
pages
651 - 657
publisher
Springer
external identifiers
  • wos:000309866200006
  • pmid:22580568
  • scopus:84867527680
ISSN
1432-1939
DOI
10.1007/s00442-012-2342-8
project
BECC
language
English
LU publication?
yes
id
85326316-f296-4b0b-98a0-25fcd229859b (old id 2608881)
date added to LUP
2012-06-11 14:17:29
date last changed
2017-01-01 03:00:24
@article{85326316-f296-4b0b-98a0-25fcd229859b,
  abstract     = {Individuals of most animal species are non-randomly distributed in space. Extreme climatic events are often ignored as potential drivers of distribution patterns, and the role of such events is difficult to assess. Seothyra henscheli (Araneae, Eresidae) is a sedentary spider found in the Namib dunes in Namibia. The spider constructs a sticky-edged silk web on the sand surface, connected to a vertical, silk-lined burrow. Above-ground web structures can be damaged by strong winds or heavy rainfall, and during dispersal spiders are susceptible to environmental extremes. Locations of burrows were mapped in three field sites in 16 out of 20 years from 1987 to 2007, and these grid-based data were used to identify the relationship between spatial patterns, climatic extremes and sampling year. According to Morisita's index, individuals had an aggregated distribution in most years and field sites, and Geary's C suggests clustering up to scales of 2 m. Individuals were more aggregated in years with high maximum wind speed and low annual precipitation. Our results suggest that clustering is a temporally stable property of populations that holds even under fluctuating burrow densities. Climatic extremes, however, affect the intensity of clustering behaviour: individuals seem to be better protected in field sites with many conspecific neighbours. We suggest that burrow-site selection is driven at least partly by conspecific cuing, and this behaviour may protect populations from collapse during extreme climatic events.},
  author       = {Birkhofer, Klaus and Henschel, Joh and Lubin, Yael},
  issn         = {1432-1939},
  keyword      = {Aggregation,Araneae,Climate,Conspecific cuing,Spatial analysis},
  language     = {eng},
  number       = {3},
  pages        = {651--657},
  publisher    = {Springer},
  series       = {Oecologia},
  title        = {Effects of extreme climatic events on small-scale spatial patterns: a 20-year study of the distribution of a desert spider.},
  url          = {http://dx.doi.org/10.1007/s00442-012-2342-8},
  volume       = {170},
  year         = {2012},
}