Abstract Detail


Chmielewski, Matthew [1], Eppley, Sarah [2].

Metacommunity structure of epiphytic bryophytes in fog-maintained patches of relict Valdivian forest of north-central Chile.

Metacommunity ecology strives to examine how interactions between local communities influence the patterns of diversity that we see within each community as well as at landscape scales. Despite the rich theoretical gains made by the field, determining the effects of metacommunity processes across different spatial scales in real communities has generally proven difficult. The scale and assigned connectivity between patches can lead to assumptions about a system that undermine our understanding of community processesā . Allowing for consideration of how scale interacts with metacommunity drivers of sub-communities, it is possible to parse communities into various connectivity levels based on the taxonomic or structural/functional guild, improving our understanding of the nuances of community assembly and maintenance. Most community landscapes are not ideally discrete, making designation of the appropriate boundaries of a given study difficult, and questions about the appropriate scale of study often remain.
We examined the metacommunity structure of epiphytic bryophyte communities in Parque Nacional Bosque Fray Jorge in north-central Chile. Our field site is characterized by fog-sustained relict patches of olivillo (Aextoxicon punctatum) surrounded by an arid scrub matrix. These patches harbor communities of epiphytic bryophytes that are not found in the surrounding matrix, and are this found at tree-landscape scales. We sampled individual trees at in 20 patches for bryophyte cover at two heights using a 0.25 x 0.25m quadrat in May and June of 2015. We applied the elements of metacommunity (EMC) structure framework at various spatial scales to determine how the delineation of scale impacts inferred structure.    
Across the landscape, the overall metacommunity exhibited a Gleasonian structure (p <0.01).  When considering individual forest patches as metacommunities (with trees hosting communities of bryophytes), structures varied from patch to patch. A Clementisan or quasi-Clementsian structure was the most represented in our study site (9/20 patches), while a Gleasonian structure was exhibited by 6 of our patches. The remaining patches exhibited either random and quasi-random species loss (2/20), or quasi-clumped loss (3/20).  When split by sampling height, both low and high samples conform to a Clementsian (low) or quasi-Clementsian (high) structure. Matching both scale and sampling locality to an appropriately informed natural history context is therefore necessary when designing studies aimed at elucidating metacommunity dynamics.

1 - Portland State University, Biology, 1719 SW 10th Avenue, SRTC Room 246, Portland, OR, 97201, United States
2 - Portland State University, Biology, PO Box 751, Portland, OR, 97207, United States

metacommunity structure
community ecology.

Presentation Type: Oral Paper
Number: 0012
Abstract ID:742
Candidate for Awards:None

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