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Start Over Coverage 109-115

1. A Himalayan monsoonal location exhibiting unusually high preponderance of C4 grasses

Creator:
Rama Das, V. S. and Vats, S. K.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
An unexpectedly large proportion of C4 grasses was found in a moderately temperate and moist Himalayan location during monsoon period. 79 % of total grasses occurring in the area were found to be C4. Several grasses hitberto unreported as C4 háve now been recorded. The principál cause for the natural abundance of C4 species is presumably low atmospheric CO2 levels rallua' tlian the aridity and warmer temperatures. The finding adds a new dimension to our knowledge of natural distribution of the C4 species.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Relationship between δ13C and photosynthetic parameters and their responses to leaf nitrogen content in six broadleaf tree species

Creator:
Zheng, S.-X. and Shangguan, Z.-P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
actual quantum yield of PS2 electron transport, broadleaved tree species, leaf nitrogen content, net photosynthetic rate, photosynthetic nitrogen use efficiency, and stable carbon isotope composition
Language:
Multiple languages
Description:
Stable carbon isotope composition (δ13C), net photosynthetic rate (PN), actual quantum yield of photosystem 2 (PS2) electron transport (ΦPS2), nitrogen content (Nc), and photosynthetic nitrogen use efficiency (PNUE) in the leaves of six broadleaf tree species were determined under field environmental conditions. The six tree species were Magnolia liliflora Desr., M. grandiflora Linn., M. denudata Desr., Prunus mume (Sieb.) Sieb. et Zucc. cv. Meiren Men, P. mume (Sieb.) Sieb. et Zucc. f. alphandii (Carr.) Rehd., and P. persica (L.) Batsch. var. rubro-plena. The relationships among δ13C, ΦPS2, P N, and PNUE, as well as their responses to Nc in the six species were also studied. Both P N and δ13C negatively correlated with Nc, but ΦPS2 positively correlated with Nc. This indicated that with Nc increase, PN and δ13C decreased, while ΦPS2 increased. There were weak negative correlations between δ13C and PNUE, and strong negative correlations (p<0.01) between ΦPS2 and PNUE. According to the variance analysis of parameters, there existed significant interspecific differences (p<0.001) of δ13C, PN, ΦPS2, PNUE, and Nc among the tree seedlings of the six tree species, which suggests that the potential photosynthetic capacities depend on plant species, irradiance, and water use capacity under field conditions. and S. X. Zheng, Z. P. Shangguan.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public