Spatial-temporal variability of terrestrial vegetation productivity in the Yangtze River Basin during 2000-2009

Effects of land use/land cover and climate changes on terrestrial net primary productivity in the Yangtze River Basin, China, from 2001 to 2010

“…Many studies indicated that vegetation productivity could benefit from climate warming by lengthening growing seasons and enhancing photosynthesis [Fang et al, 2003;Field et al, 1998;Myneni et al, 1997;Nemani et al, 2003;Piao et al, 2005;Potter et al, 2012], while other studies showed that warmer climate could increase plant's autotrophic respiration and potentially reduce NPP especially in the high-temperature regions [King et al, 2006;Piao et al, 2008;Zhao and Running, 2010;Zhang et al, 2013]. Although YRB-CASA does not explicitly model autotrophic respiration, the temperature scalars (Tε 1 and Tε 2 in equation (1)) have a similar effect on NPP [Potter et al, 1993].…”

“…However, the treatment of temperature and water stress as two independent environmental factors in this paper may not properly separate the effects of warming and water stress on NPP. Most croplands in the YRB are highly managed with fertilization and irrigation, thus might not respond to the drought stress as the natural vegetation do [Xu and Ma, 2009;Zhang et al, 2013]. The scenario C3 may overestimate the effect of water stress on crops.…”

“…Therefore, the first decade in the 21st century for the YRB provides a unique window to evaluate the effects of fast LULCC and rapid climate change on terrestrial ecosystem productivity in a large human-dominated landscape. While some ecological consequences of LULCC and climate change have been discussed across this region [Zhao et al, 2006b;Liu et al, 2010;Piao et al, 2010;Zhang et al, 2013], a comprehensive analysis of terrestrial ecosystem productivity with respect to these two factors has not been performed yet.…”

Análise do Sequestro de Carbono em Áreas de Caatinga do Semiárido Pernambucano

“…Zhang et al (2014), por exemplo, analisaram a variabilidade espaço-temporal da NPP associada a GPP para a bacia do rio Yang Tze, na China, de 2000 a 2009, e encontraram GPP e NPP variando de 530 a 958 g C m 2 /ano e 272 a 489 g C m 2 /ano, respectivamente, em áreas de savanas arbóreas. Yu et al (2009) estimaram valores médios anuais de NPP de 144 g C/m 2 para vegetação arbustiva aberta, 228 g C/m 2 para pastagens, e 266 g C/m 2 para vegetação arbustiva fechada inseridas na Ásia oriental.…”

Empirical evidence of El Niño–Southern Oscillation influence on land surface phenology and productivity in the western United States

“…In fact, zonal Δ NPP is never less than zero, indicating that productivity in El Niño years is consistently higher than in La Niña years throughout the western U.S. Interestingly, zonal Δ NPP exhibits very different patterns from zonal Δ LOS . Despite the expectation that changes in growing season length would be associated with proportional changes in NPP, Δ LOS peaks near latitudes 32°N and 38°N while differences in NPP peak between 32°-36°N and 47°-49°N, suggesting that a longer and warmer growing season does not necessarily lead to proportional increases in NPP, perhaps due to increased water stress (Angert et al, 2005;Brzostek et al, 2014;Hu, Moore, Burns, & Monson, 2010) or costs associated with autotrophic respiration (Zhang, Song, Zhang, Cheng, & Zhang, 2014). Comparison of maximum vegetation indices in El Niño and La Niña years (not shown) also suggests that this could be related to higher peak photosynthetic activity during El Niño years (though this El Niño-related increase in maximum vegetation index during the full 1982-2011 period was more muted than in the shorter 2000-2011 period).…”