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DOI	10.5194/hess-23-5069-2019
	Pattern and structure of microtopography implies autogenic origins in forested wetlands
	Diamond J.S.; McLaughlin D.L.; Slesak R.A.; Stovall A.
发表日期	2019
ISSN	1027-5606
起始页码	5069
结束页码	5088
卷号	23 期号:12
英文摘要	Wetland microtopography is a visually striking feature, but also critically influences biogeochemical processes at both the scale of its observation (10-2-102 m2) and at aggregate scales (102-104 m2). However, relatively little is known about how wetland microtopography develops or the factors influencing its structure and pattern. Growing research across different ecosystems suggests that reinforcing processes may be common between plants and their environment, resulting in self-organized patch features, like hummocks. Here, we used landscape ecology metrics and diagnostics to evaluate the plausibility of plant-environment feedback mechanisms in the maintenance of wetland microtopography. We used terrestrial laser scanning (TLS) to quantify the sizing and spatial distribution of hummocks in 10 black ash (Fraxinus nigra Marshall) wetlands in northern Minnesota, USA. We observed clear elevation bimodality in our wettest sites, indicating microsite divergence into two states: elevated hummocks and low elevation hollows. We coupled the TLS dataset to a 3-year water level record and soil-depth measurements, and showed that hummock height (meanD0:31±0:06 m) variability is largely predicted by mean water level depth (R2 D 0:8 at the site scale, R2 D 0:12-0.56 at the hummock scale), with little influence of subsurface microtopography on surface microtopography. Hummocks at wetter sites exhibited regular spatial patterning (i.e., regular spacing of ca. 1.5 m, 25 %-30% further apart than expected by chance) in contrast to the more random spatial arrangements of hummocks at drier sites. Hummock size distributions (perimeters, areas, and volumes) were lognormal, with a characteristic patch area of approximately 1m2 across sites. Hummocks increase the effective soil surface area for redox gradients and exchange interfaces in black ash wetlands by up to 32 %, and influence surface water dynamics through modulation of specific yield by up to 30 %. Taken together, the data support the hypothesis that vegetation develops and maintains hummocks in response to anaerobic stresses from saturated soils, with a potential for a microtopographic signature of life. © 2019 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	Ecology; Plants (botany); Size distribution; Soils; Surface waters; Surveying instruments; Water levels; Biogeochemical process; Feedback mechanisms; Influence surfaces; Landscape ecology; Spatial arrangements; Spatial patterning; Surface microtopography; Terrestrial laser scanning; Wetlands; aggregate size; ash; data set; divergence; forested catchment; hummocky cross-stratification; laser method; microtopography; soil depth; terrestrial environment; water level; Minnesota; United States; Fraxinus nigra
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159545
作者单位	Diamond, J.S., Quantitative Ecohydrology Laboratory, RiverLy, Irstea, Lyon, 69100, France, Continental Geo-hydrosystems Laboratory, University of Tours, Tours, 37200, France; McLaughlin, D.L., School of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, 24060, United States; Slesak, R.A., Minnesota Forest Resources Council, St. Paul, 55108, United States; Stovall, A., NASA Goddard Space Flight Center, Greenbelt, 20771, United States
推荐引用方式 GB/T 7714	Diamond J.S.,McLaughlin D.L.,Slesak R.A.,et al. Pattern and structure of microtopography implies autogenic origins in forested wetlands[J],2019,23(12).
APA	Diamond J.S.,McLaughlin D.L.,Slesak R.A.,&Stovall A..(2019).Pattern and structure of microtopography implies autogenic origins in forested wetlands.Hydrology and Earth System Sciences,23(12).
MLA	Diamond J.S.,et al."Pattern and structure of microtopography implies autogenic origins in forested wetlands".Hydrology and Earth System Sciences 23.12(2019).