Soil microedges provide an ecological niche for Desmodium canadense
Within a plant community, variation among species in their abilities to exploit different types of soil patches can promote increased species diversity. However, it also has been suggested that some species may be disproportionately abundant along the edges between soil patches (i.e. soil microedges). We investigated the potential mechanisms whereby microedges can offer distinct ecological niches. Desmodium canadense, a tallgrass prairie species observed anecdotally to be abundant along patch edges, was grown in homogenized sandy loam (low-quality patch), clay loam (high-quality patch), or along the microedge between these two substrates, both in the presence or absence of competitors (Andropogon gerardii and Solidago juncea). Treatment effects on the biomass and root foraging strategies of D. canadense were assessed and compared to the responses of Andropogon gerardii and Solidago juncea. Although D. canadense biomass was highest in the clay loam without competition, with competition D. canadense biomass was highest along the microedge, which was a pattern not observed in A. gerardii or S. juncea. D. canadense also exhibited disproportionate root proliferation along the microedge into the clay loam patch, regardless of competitor presence. Although D. canadense biomass can be limited in both low- and high-quality soil patches, the edges between these patches allow D. canadense to avoid intense aboveground competition yet still access beneficial soil patches through lateral root foraging, thus enabling soil patch microedges to serve as a unique ecological niche.
KeywordsEcological boundary Soil heterogeneity Tallgrass prairie Coexistence Niche partitioning Ecotone
This research was supported by a NSERC Discovery Grant awarded to HALH. Previous versions of this work were improved by comments and suggestions from Greg Thorn, Sheila Macfie, and Jennifer Baron.
- Bátori Z, Erdős L, Kelemen A, Deák B, Valkó O, Gallé R, Bragina TM, Kiss PJ, Kröel-Dulay G, Tölgyesi C (2018) Diversity patterns in sandy forest-steppes: a comparative study from the western and central Palaearctic. Biodivers Conserv 27:1011–1030. https://doi.org/10.1007/s10531-017-1477-7 CrossRefGoogle Scholar
- Core Team R (2019) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, AustriaGoogle Scholar
- Hennenberg KJ, Goetze D, Kouamé L, Orthmann B, Porembski S (2005) Border and ecotone detection by vegetation composition along forest-savanna transects in Ivory Coast. J Veg Sci 16:301–310. https://doi.org/10.1111/j.1654-1103.2005.tb02368.x CrossRefGoogle Scholar
- Henry J, Bruckerhoff S, Kaiser J (2006) USDA plant fact sheet: showy ticktrefoil. USDA Natural Resources Conservation Service. https://plants.usda.gov/factsheet/pdf/fs_deca7.pdf. Accessed 26 May 2018
- Hutchings MJ, de Kroon H (1994) Foraging in plants: the role of morphological plasticity in resource acquisition. In: Begon M, Fitter AH (eds) Advances in ecological research, 1st edn. Academic Press, San Diego, pp 159–238Google Scholar
- Jenny H (1994) Factors of soil formation: a system of quantitative pedology. Courier Corporation, New YorkGoogle Scholar
- Ries L, Fletcher RJ, Battin J, Sisk TD (2004) Ecological responses to habitat edges: mechanisms, nodels, and variability explained. Annu Rev Ecol Evol S 35:491–522. https://doi.org/10.1146/annurev.ecolsys.35.112202.130148 CrossRefGoogle Scholar
- Stover HJ (2018) Soil homogenization: plant species diversity, ecosystem properties and soil freezing effects during tallgrass prairie restoration. Western University, Doctor of PhilosophyGoogle Scholar
- Strayer DL, Power ME, Fagan WF, Pickett STA, Belnap J (2003) A classification of ecological boundaries. Bioscience 53:723–729. https://doi.org/10.1641/0006-3568(2003)053[0723:ACOEB]2.0.CO;2 CrossRefGoogle Scholar
- Weiner J (1993) Competition among plants. Treballs de la SCB 44:99–109Google Scholar