TY - JOUR
T1 - Biophysical Regulation of Net Ecosystem Carbon Dioxide Exchange over an Artificial Pasture in the Three-River Source Region of the Qinghai-Tibetan Plateau
AU - Gu, Song AU - Wang, Bin AU - Li, Jie AU - Zhao, Liang AU - Xu, Shixiao AU - Tang, Yanhong AU - Du, Mingyuan
JO - Journal of Animal and Veterinary Advances
VL - 12
IS - 19
SP - 1512
EP - 1523
PY - 2013
DA - 2001/08/19
SN - 1680-5593
DO - javaa.2013.1512.1523
UR - https://makhillpublications.co/view-article.php?doi=javaa.2013.1512.1523
KW - Net ecosystem CO2 exchange
KW -ecosystem respiration
KW -artificial pasture
KW -Elymus nutans
KW -eddy
AB - Measurements of Net Ecosystem CO2 Exchange (NEE) were made, using
eddy covariance to investigate the biophysical regulation of an Elymus nutans
artificial pasture in the Three-River Source Region on the Qinghai-Tibetan Plateau
during 2008. The hourly maximum rates of NEE was -7.89 μmol CO2/m2/sec
(negative values representing net carbon uptake). The maximum daily NEE for
the pasture was -2.91 g/cm2/day. The annual NEE sums in pasture was
140.01 g cm2/year. For the entire growing period, the light response
curves of daytime NEE showed a medium apparent quantum yield (α = -0.0275
μmol μmol-1). However, the α values varied with varied
with canopy development, air temperature (Ta) and Soil Water Content
(SWC) and Vapor Pressure Deficit (VPD). Piecewise regression results suggested
that the optimal Ta and VPD for hourly daytime NEE were 14.1°C
and 0.65 kPa, respectively. During the entire growing period, the daytime NEE
decreased as the SWC increased. The apparent temperature sensitivities of ecosystem
respiration (Q10) was 3.0 for the entire growing season and it was
significantly controlled by soil moisture. During the growing season, the leaf
area index explained approximately 32.5% of the variation in daily NEE.
ER -