Competition and aspect contribute to saxicolous lichen species distribution on serpentine outcroppings at Sedgwick Reserve, California

Author:
Sisneros T., Gerhardt K., Conklin A. & Hu C.
Year:
2021
Journal:
California Ecology and Conservation Research
Pages:
5(6): 1-12
Url:
https://ucnrs.org/wp-content/uploads/2021/11/Competition-and-aspect-contribute-to-saxicolous-lichen-species-distribution-on-serpentine-outcroppings-at-Sedgwick-Reserve-California.pdf
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Lichens are hardy organisms that can survive in some of the harshest conditions in which terrestrial biota is found. These conditions can lead to highly competitive systems, where organisms compete for limited resources and spaces with the most favorable conditions. However, in many instances, species are found coexisting without issue. There exist mechanisms that maintain biodiversity including disturbance, niche partitioning, and habitat differentiation. In the absence of such stabilizing mechanisms, other mitigating factors such as intransitivity, an ecological game of “rock-paper-scissors” may come into play. This alternative mechanism creates a system where competing species effectively limit the populations of one another without ever fully excluding a species, allowing multiple species to coexist on the same resource. Our study investigated the distribution of saxicolous lichen communities on serpentine outcroppings and evaluated if any such coexistence mechanisms could be identified. We found no evidence of intransitive interactions. However, we found that certain lichen species distribute themselves differently according to the aspect of the rock they grew on. We also found that the species that excelled in interference competition did not exhibit the greatest percent cover overall. Our findings have implications for not only the energetic trade-offs that may accompany alternative competitive strategies but for the ability of species to coexist via spatial resource partitioning.
Id:
37630
Submitter:
jph
Post_time:
Tuesday, 04 February 2025 19:58