کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6409911 1629913 2016 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Measurements of coarse particulate organic matter transport in steep mountain streams and estimates of decadal CPOM exports
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Measurements of coarse particulate organic matter transport in steep mountain streams and estimates of decadal CPOM exports
چکیده انگلیسی


- CPOM transport is fairly well measurable with bedload traps in wadeable streams.
- Pronounced hysteresis requires intensive sampling for accurate estimating CPOM load.
- Known CPOM hysteresis patterns useful for enhancing poorly sampled CPOM time series.
- Rough estimates of CPOM transport relation possible in coniferous mountain streams.
- Decadal CPOM export estimate: 11 t/yr load, 21 kg/ha/yr yield (forested basin area).

SummaryCoarse particulate organic matter (CPOM) provides a food source for benthic organisms, and the fluvial transport of CPOM is one of the forms in which carbon is exported from a forested basin. However, little is known about transport dynamics of CPOM, its relation to discharge, and its annual exports from mountain streams. Much of this knowledge gap is due to sampling difficulties. In this study, CPOM was sampled over one-month snowmelt high flow seasons in two high-elevation, subalpine, streams in the Rocky Mountains. Bedload traps developed for sampling gravel bedload were found to be suitable samplers for CPOM transport. CPOM transport rates were well related to flow in consecutive samples but showed pronounced hysteresis over the diurnal fluctuations of flow, between consecutive days, and over the rising and falling limbs of the high-flow season. In order to compute annual CPOM load, hysteresis effects require intensive sampling and establishing separate rating curves for all rising and falling limbs. Hysteresis patterns of CPOM transport relations identified in the well-sampled study streams may aid with estimates of CPOM transport and export in less well-sampled Rocky Mountain streams. Transport relations for CPOM were similar among three high elevation mountain stream with mainly coniferous watersheds. Differences among streams can be qualitatively attributed to differences in CPOM contributions from litter fall, from the presence of large woody debris, its grinding into CPOM sized particles by gravel-cobble bedload transport, hillslope connectivity, drainage density, and biological consumption. CPOM loads were 3.6 and 3.2 t/yr for the two Rocky Mountain streams. Adjusted to reflect decadal averages, values increased to 11.3 and 10.2 t/yr. CPOM yields related to the entire watershed were 2.7 and 4 kg/ha/yr for the years studied, but both streams exported similar amounts of 6.5 and 6.6 kg/ha/yr when taking the forested portion of the watershed into account. To reflect decadal averages, CPOM yields per basin area were adjusted to 8.6 and 12.6 kg/ha/yr and to 21 kg/ha/yr for the forested watershed parts. CPOM yield may be more meaningfully characterized if annual CPOM loads are normalized by the area of a seam along the stream banks together with the stream surface area rather than by the forested or total watershed area.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hydrology - Volume 539, August 2016, Pages 162-176
نویسندگان
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