scholarly journals Impact of environmental factors on the decoupling coefficient and the estimation of canopy stomatal conductance for ever-green broad-leaved tree species

2018 ◽  
Vol 42 (12) ◽  
pp. 1179-1191 ◽  
Author(s):  
Zhen-Zhen ZHANG ◽  
◽  
Ping ZHAO ◽  
Xiu-Hua ZHAO ◽  
Jin-Xiu ZHANG ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Environmental Factors ◽  
Tree Species ◽  
Canopy Stomatal Conductance ◽  
Decoupling Coefficient

Influence of the decoupling degree on the estimation of canopy stomatal conductance for two broadleaf tree species

2016 ◽  
Vol 221 ◽  
pp. 230-241 ◽  
Author(s):  
Zhen Z. Zhang ◽  
Ping Zhao ◽  
Heather R. McCarthy ◽  
Xiu H. Zhao ◽  
Jun F. Niu ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Tree Species ◽  
Broadleaf Tree ◽  
Canopy Stomatal Conductance

scholarly journals Stomatal conductance limited the CO2 response of grassland in the last century

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Juan C. Baca Cabrera ◽  
Regina T. Hirl ◽  
Rudi Schäufele ◽  
Andy Macdonald ◽  
Hans Schnyder
Keyword(s):  
Climate Change ◽  
Stomatal Conductance ◽  
Nitrogen Nutrition ◽  
Physiological Control ◽  
Co2 Response ◽  
Nitrogen Acquisition ◽  
Wide Range ◽  
Park Grass Experiment ◽  
Conductance Changes ◽  
Canopy Stomatal Conductance

Abstract Background The anthropogenic increase of atmospheric CO2 concentration (ca) is impacting carbon (C), water, and nitrogen (N) cycles in grassland and other terrestrial biomes. Plant canopy stomatal conductance is a key player in these coupled cycles: it is a physiological control of vegetation water use efficiency (the ratio of C gain by photosynthesis to water loss by transpiration), and it responds to photosynthetic activity, which is influenced by vegetation N status. It is unknown if the ca-increase and climate change over the last century have already affected canopy stomatal conductance and its links with C and N processes in grassland. Results Here, we assessed two independent proxies of (growing season-integrating canopy-scale) stomatal conductance changes over the last century: trends of δ18O in cellulose (δ18Ocellulose) in archived herbage from a wide range of grassland communities on the Park Grass Experiment at Rothamsted (U.K.) and changes of the ratio of yields to the CO2 concentration gradient between the atmosphere and the leaf internal gas space (ca – ci). The two proxies correlated closely (R2 = 0.70), in agreement with the hypothesis. In addition, the sensitivity of δ18Ocellulose changes to estimated stomatal conductance changes agreed broadly with published sensitivities across a range of contemporary field and controlled environment studies, further supporting the utility of δ18Ocellulose changes for historical reconstruction of stomatal conductance changes at Park Grass. Trends of δ18Ocellulose differed strongly between plots and indicated much greater reductions of stomatal conductance in grass-rich than dicot-rich communities. Reductions of stomatal conductance were connected with reductions of yield trends, nitrogen acquisition, and nitrogen nutrition index. Although all plots were nitrogen-limited or phosphorus- and nitrogen-co-limited to different degrees, long-term reductions of stomatal conductance were largely independent of fertilizer regimes and soil pH, except for nitrogen fertilizer supply which promoted the abundance of grasses. Conclusions Our data indicate that some types of temperate grassland may have attained saturation of C sink activity more than one century ago. Increasing N fertilizer supply may not be an effective climate change mitigation strategy in many grasslands, as it promotes the expansion of grasses at the disadvantage of the more CO2 responsive forbs and N-fixing legumes.

scholarly journals Spatial pattern of riparian plants along stream order among mountain rivers in China

2018 ◽  
Vol 9 (2) ◽  
pp. 322-330
Author(s):  
Rong Sun ◽  
Xiaojie Luo ◽  
Xiangyu Meng ◽  
Yan Wang
Keyword(s):  
Species Richness ◽  
Environmental Factors ◽  
Tree Species ◽  
Riparian Vegetation ◽  
Stream Order ◽  
River Continuum ◽  
Riparian Plants ◽  
Tree Species Richness ◽  
Riparian Species ◽  
Significant Difference

Abstract The streams in a watershed form a hierarchical network system. From the perspective of the river continuum, this classification system is the result of gradual increase in traffic. This study analyzed the riparian species richness, diversity and environmental factors along a six-order hierarchical mountain river in the Donghe watershed, China. A total of 34 sampling sites were sampled to study the spatial distribution of riparian plants among different stream orders. The results showed: Environmental factors among stream orders had significant differences. Among stream order, species richness showed remarkable differences. The species richness rose firstly and dropped afterwards except for tree species richness; tree species richness decreased while stream order increased. The same is true for shrub quadrat species richness. Shannon-Wiener diversity, Simpson dominance and Pielou uniformity showed significant difference among stream orders; Shannon-Wiener diversity rose firstly then dropped afterwards. For integrated environmental factors and community characteristics, we found the changes of stream orders had a significant impact on riparian habitats and riparian vegetation. Further analysis showed that riparian vegetation experienced different types and degrees of disturbance in different stream orders. This meant that a hierarchical management strategy should be applied to riparian vegetation management.

Assessment of canopy stomatal conductance models using flux measurements

2009 ◽  
Vol 220 (17) ◽  
pp. 2115-2118 ◽  
Author(s):  
Shusen Wang ◽  
Yan Yang ◽  
Alexander P. Trishchenko
Keyword(s):  
Stomatal Conductance ◽  
Flux Measurements ◽  
Canopy Stomatal Conductance
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