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Start Over Coverage 43-48

3. Natural occurrence and backwater Infection of C4 plants in the vegetation of the Yangtze hydropower Three Gorges Project region

Creator:
Wang, R. Z.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
altitude pattern, geophytes, hemicryptophytes, life form, and therophytes
Language:
Multiple languages
Description:
Natural occurrence of C4 species, life form, altitude pattern, and infection by the Three Gorges Project (TGP) were studied in the TGP region. 76 species (about 2.5 % of the total 2 685 vascular plant species in the region), in 6 families and 42 genera, were identified with C4 photosynthesis. 91 % of these C4 species belong to Monocotyledoneae, e.g. Cyperaceae (14 species), Gramineae (54 species), and Commelinaceae (1 species). Of these C4 species, Gramineae was the leading C4 family: 54 C4 grass species (71 % of the total C4 species), about 36 % of the total grasses, were identified in the TGP region. 98 % C4 species was found in therophyte (55 %) and hemicryptophyte (43 %). This is consistent with high grass and sedge compositions in the region. Most habitats of more than a half of these C4 species (65 %) will be submerged permanently, but no species will be endangered or extinct, because 95 % C4 species can be found from 500 to 800 m above sea level. The abundance of some C4 species will be dropped due to the reduction of distribution scope. It will take a long-term to explore the effects of the TGP on plants, vegetation, and environment.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Photosynthesis of different ecotypes of Miscanthus spp. as affected by water stress

Creator:
Weng, J.-H.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
Four dones of Miscanthus spp., collected from regions with different rainfall distribution, were transplanted in pots and subjected to five drying cycles (each of 6- 7 d). Gas exchanges were measured on attached leaves, The light-saturated photosynthetic CO2 uptake (P^) began to dechne when the leaf water potential (y\) was reduced to -1.3 - -1.5 MPa, and the values corresponding to 50 % decrease P^)] were -1.6 - -2.6 MPa. The P^ ) values were lower in a cloně collected from Kilung (northem Taiwan, highly frequent rainfall) than in dones collected from Kenting (southem Taiwan, distinct wet and dry season). Besides, the ^(1/2 Pj^) value became lower in all the tested dones when the drying cycle advanced (in the drying cycle of northem Taiwan cloně and in the 5‘*’ drying cycle of southem Taiwan dones, řespectively). Both the stomatal and non- stomatal factors of photosynthesis were affected by water deficit, and the osmotic adjustment mitigated the negative impact of water deficit on both factors. The clonal differences in the tolerance and acdimation of photosynthesis to water deficit are dosely related to the osmotic adjustment, and the clonal differences in osmotic adjustment reflect the rainfall pattem of sampled region.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. The photosynthetic performance of six early successional tropical tree species

Creator:
Tan, G.C.-H., Ong, B.-L., and Turner, I.M.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
Field measurements of gas exchange were made using a portable infra-red gas analyser on six species of early-successional woody plants in Singapore. Macaranga heynei, Mallotus paniculatus and Trema tomentosa grow on relatively fertile soils. Adinandra dumosa, Uillenia suffruticosa and Melostoma malabalhricum are species typical of extremely acidic and infertile soils. The six species were similar in their photosynthetic responses to irradiance when net photosynthetic rate (P^) was expressed on a leaf area basis. However, when PN was converted to a rate per unit leaf dry mass, the fertile soil species showed higher rates of dark respiration and photosynthesis. No difference in water use efficiency between the two sets of species was found.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public