Literaturdatenbank
Literaturdatenbank |
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Kinlaw, A., & Grasmueck, M. (2011). Evidence for and geomorphologic consequences of a reptilian ecosystem engineer: the burrowing cascade initiated by the gopher tortoise. Geomorphology, (article in press).
Added by: Sarina Wunderlich (28 Aug 2011 21:15:13 UTC) |
| Resource type: Journal Article DOI: 10.1016/j.geomorph.2011.06.030 BibTeX citation key: Kinlaw2011 View all bibliographic details  |
Categories: General Keywords: Gopherus, Gopherus polyphemus, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Testudinidae Creators: Grasmueck, Kinlaw Collection: Geomorphology |
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| Abstract |
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Testudinidae bstract Physical ecosystem engineers often make major, durable physical constructs that can provide living space for other species and can structure local animal communities over evolutionary time. In Florida, a medium sized chelonian, the Gopher Tortoise (Gopherus polyphemus) will excavate extensive subterranean chambers that can endure for long periods of time. The tortoise starts a ‘burrowing cascade’, by first excavating a larger burrow that may extend 10 m, which is then re-engineered by Florida Mice (Podomys floridanus) and other rodents that dig smaller side-burrows and pockets. This sequence is often followed by an invertebrate, the camel cricket (Ceuthophilus labibuli) which is reported to excavate even smaller chambers. Our first aim was to quantify the zoogeomorphic impact of this burrowing cascade by measuring the amount of soil excavated in a large sample of burrows in two communities. Secondly, we hypothesized that the high biodiversity reported for these structures might be related to the quasi-fractal nature of the geometry, following the work of Frontier (1987). To visualize this underground geometry, we used high-resolution 3D Ground Penetrating Radar (GPR), which provided images and insights previously unobtainable using excavations or 2D GPR. Our images verified that the active tortoise burrow had a spiraling shape, but also showed splits in the larger burrow apparently dug by tortoises. For the first time, the smaller Florida Mouse burrows were imaged, showing side loops that exit and re-renter the tortoise burrow. This study also presents new information by making the discovery of numerous remnants of past tortoise burrows deeper underground in the sampling grid surrounding the active burrow. Our third aim was to interpret our field results with previous ecological field studies to evaluate the strength of evidence that this species ranks as an ecosystem engineer. Highlights ► Gopher tortoises can excavate 11 times more soil in sandhill habitat compared to scrub ► A high resolution GPR imaging study was conducted at tortoise burrows in Florida ► We discovered relic tortoise burrows located near active tortoise burrows but deeper underground ► Florida Mouse burrows were imaged showing side loops that exit and re-renter the tortoise burrow ► This study and previous studies show that this species ranks as an ecosystem engineer.
Added by: Sarina Wunderlich |