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221.
Lowland ombrotrophic (rain-fed) peatlands are a declining ecological resource in Europe. Peatlands display characteristic
patterns in vegetation and surface topography, linked to ecological function, hydrology, biodiversity and carbon sequestration.
Laser scanning provides a means of precisely measuring vegetation pattern in peatlands, and thus holds promise as a tool for
monitoring peatland condition. Terrestrial laser scanning (TLS) was used for measurement of vegetation pattern along an eco-hydrological
gradient at a UK peatland (Wedholme Flow, Cumbria) at fine grain sizes (<1 cm spatial resolution over 10 m spatial extent).
Seven sites were investigated—each showed varying water table and ecological characteristics. TLS data were analysed using
semi-variogram analysis which enabled the scale of spatial dependence in vegetation structures to be measured. In addition
ecological, hydrological and positional surveys were conducted to elucidate interpretation of spatial patterns. Results show
that TLS was able to rapidly measure vegetation patterns associated with eco-hydrological condition classes. Intact sites
with hummock-hollow topography showed an isotropic pattern with a grain size or length-scale of 1 m or less (indicated by
semi-variogram range). Degraded sites with high shrub cover showed increased sill variance values at larger range distances—typically
around 3–4 m. The work presented shows the advantages of TLS methodologies for rapid measurement of 3-D vegetation canopy
structure and surface microtopography, at fine spatial scales, in short vegetation. The paper considers how these approaches
may be extended to monitoring peatland structure over larger spatial extents from airborne LiDAR systems. 相似文献
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Background
Although Nicotiana attenuata is entirely self-compatible, chemical and other floral traits suggest selection for the maintenance of advertisement for moth pollinators. 相似文献224.
Steinberg EJ Prata RG Palazzini K Brown DC 《Journal of the American Animal Hospital Association》2011,47(4):250-257
The purpose of this retrospective study of 171 dogs that underwent 193 tibial tuberosity advancement (TTA) surgeries was to describe complications and owner satisfaction associated with the procedure. Complications occurred in 21 cases (11%). Subsequent meniscal tear was the most common complication (10/193, 5.2%). Increasing body weight (P=0.02-0.04) and small cage size (P=0.06) were significantly associated with postsurgical complications. Ninety-two percent of owners were satisfied with the outcome of the TTA procedure, but only 84% stated that they would be willing to have the procedure performed again. The authors concluded that TTA had a complication rate and owner satisfaction similar to other tibial osteotomies for the surgical correction of cranial cruciate ligament disease. 相似文献
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