Abstract Detail

Ecology

Thoen, Riley Daniel [1], Roy, Bitty A [2], Reed, Paul B [3], Cruzan, Mitchell [4], Hendricks, Lauren B [5], Johnson, Bart R [6], Pfeifer-Meister, Laurel E [7], DeMarche, Megan [8].

Spatiotemporal variation in population dynamics of a narrow endemic, Ranunculus austro-oreganus.

Understanding variation of population growth in space and time is necessary to determine reduce overall extinction risk, especially for narrow-ranged species. Here, we ask how much population growth and vital rates differ across sites and years for Ranunculus austro-oreganus, a rare endemic perennial buttercup native to fragmented prairie in one county in south Oregon. We use size-based integral projection models to assess population dynamics in three populations of Ranunculus austro-oreganus across three transitions (2015-2018). We found population growth differed more across our three sites than across years, with a growing, declining, and stable population. Population growth was most sensitive to flowering probability and seedling growth, and these vital rates drove differences in viability across populations. Differences in population growth among sites may be explained by differences in habitat and the degree of introgression. Population growth was greater in sites with flatter slopes and deeper soils. Interestingly, the declining population experienced less adaptive introgression from a widespread congener relative to the growing and stable populations. This study shows that populations of range-restricted species may differ considerably in their viability.

1 - University of Georgia, Department of Plant Biology, 120 Carlton St, Athens, Georgia, 30602, USA
2 - University of Oregon, Department of Biology, 77 Klamath Hall, Eugene, OR, 97403, USA
3 - University of Oregon, Institute of Ecology and Evolution, 77 Klamath Hall, Eugene, OR, 97403, USA
4 - Portland State University, Department Of Biology, 1719 SW 10th Ave, SRTC Rm 246 - Biology, Portland, OR, 97201, United States
5 - University of Oregon, Department of Geography, 107 Condon Hall, Eugene, OR, 97403, USA
6 - University of Oregon, Department of Landscape Architecture, Eugene, OR, 97403, USA
7 - University of Oregon, Institute of Ecology and Evolution, Eugene, OR, 97403, USA
8 - University of Georgia, Department of Plant Biology, Athens, GA, 30602, USA

Keywords:
demography
Prairies
Vital rates
integral projection model.

Presentation Type: Oral Paper
Number:
Abstract ID:1012
Candidate for Awards:None