کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7461024 | 1484616 | 2015 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Environmental control over seasonal variation in carbon fluxes of an urban temperate forest ecosystem
ترجمه فارسی عنوان
کنترل محیط زیست بر تغییرات فصلی در جریان کربن یک اکوسیستم جنگل معتدل شهری
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کلمات کلیدی
جنگل شهری، بهره وری اکوسیستم خالص، تنفس اکوسیستم، تولید ناخالص اکوسیستم، گرم شدن خشکی،
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
بوم شناسی، تکامل، رفتار و سامانه شناسی
چکیده انگلیسی
Knowledge of surface-atmosphere CO2 exchanges in urban forests is imperative. We measured net ecosystem CO2 exchange of an urban forest in Beijing over a two-year period (2012-2013). The aim was to examine seasonal controls of environmental variables on ecosystem carbon (C) cycle assessed with eddy covariance technique. Net ecosystem production (NEP) was 30% less in 2012 (200 ± 27 g C mâ2) than in 2013 (287 ± 35 g C mâ2). Both years were warmer than the long-term average. Seasonal and annual ratios of ecosystem respiration (ER) to gross primary productivity (GEP) were higher in 2012 than in 2013. Dry conditions decreased GEP more than ER, while warm conditions increased ER more than GEP. Heat stress exerted controls over seasonal changes in NEP. Daytime NEP ceased to increase beyond 11 μmol CO2 mâ2 sâ1 and 13 μmol CO2 mâ2 sâ1 in 2012 and 2013, respectively, where mean photosynthetically active radiation was >700 μmol mâ2 sâ1 and air temperatures was greatest (>27 °C) in mid-summer days. The extremely strong precipitation day (176 mm) was recorded as having the greatest C discharge to the atmosphere (5.6 g C mâ2). Intermediate-size precipitation events (>2 mm and â¤15 mm) acted to increase C-sink strength. The results highlight the roles of environmental stresses and their alleviation in regulating C fixation in the face of warmer climate and increasing intensity of extreme precipitation events.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Landscape and Urban Planning - Volume 142, October 2015, Pages 63-70
Journal: Landscape and Urban Planning - Volume 142, October 2015, Pages 63-70
نویسندگان
Jing Xie, Xin Jia, Guimei He, Caixian Zhou, Haiqun Yu, Yajuan Wu, Charles P.-A. Bourque, He Liu, Tianshan Zha,