کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
82834 158420 2008 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ecosystem respiration and its components in an old-growth forest in the Great Lakes region of the United States
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
پیش نمایش صفحه اول مقاله
Ecosystem respiration and its components in an old-growth forest in the Great Lakes region of the United States
چکیده انگلیسی

Ecosystem respiration and its components are sensitive to age, species, stand structure, and environmental conditions, and substantially influence net ecosystem productivity. We measured ecosystem respiration and component respiration including soil, woody debris, stem and leaf respiration in old-growth hardwood-dominated and hemlock-dominated stands in northern Michigan, USA in 2002 and 2003. Respiration was mainly controlled by temperature, peaked in July–August and reached minimums in January–March. Total ecosystem respiration averaged 1013 g C m−2 y−1 in the hardwood stand and 922 g C m−2 y−1 in the hemlock stand. Cumulative annual soil respiration, coarse woody debris respiration, stem respiration, and leaf respiration were 724, 43, 131, 115 g C m−2 y−1, respectively, accounting for 72%, 4%, 13%, and 11% of total ecosystem respiration in the hardwood stand, and 614, 29, 207, 72 g C m−2 y−1, respectively, accounting for 67%, 3%, 22%, and 8% in the hemlock stand. Ecosystem respiration and its components except for leaf respiration in 2002 were larger than year 2003 due primarily to lower temperature in 2003. Component respiration except for stem respiration was higher in the hardwood stand than the hemlock stand. Daily mean ecosystem respiration upscaled from chamber measurements agreed well with eddy covariance measurements, with r2 of 0.96. By comparing respiration from the old-growth with a nearby young and a mature second-growth forest based on chamber measurements, we found that both age class and species are important in determining the magnitude and proportion of component respiration. Total ecosystem respiration generally increased from the young forest to the mature forest, and then decreased from the mature to the old-growth forest.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Agricultural and Forest Meteorology - Volume 148, Issue 2, 13 February 2008, Pages 171–185
نویسندگان
, , , , , , ,