中国-喜马拉雅地区硬叶栎林的特点与分类

本文对中国—喜马拉雅地区的硬叶栎林,研究了它的主要特点和分类系统。根据硬叶栎林地区各气象站气候图解的特点(“A”字形),认为硬叶栎林是夏雨区的硬叶林,它不同于世界上冬南区的(“U”字形气候图解)硬叶林。 根据硬叶栎林的植物区系和生态环境,它不属于亚热带的照叶林和地中海型的硬叶林,而是中国—喜马拉雅地区特有的夏雨硬叶林,在中国西部高山地区的阳坡上常为顶极群落。根据硬叶栎林的优势树种和海拔、气候、土壤及伴生树种,分为10个群系和两个群系组。     

Biological spectrum and other structural functional attributes of the vegetation of Kumaun Himalaya

Spectra on life form, leaf size, leaf persistence, flowering season, and shade tolerance of trees in different vegetation types occurring within the north-western catchment of the river Gola in Kumaun Himalaya are presented. The flora of Quercus leucotrichophora, Quercus lanuginosa and Quercus floribunda forests is phanerophytic, that of Pinus roxburghii and mixed forests therophytic. The grassland vegetation is characterized by the largest percentage of hemicryptophytes. The flora of the whole area, is therophytic. The biological spectrum for the entire Kumaun Himalaya is characterized as therohemigeophytic. Among the various altitudinal zones, the tropical has a preponderance of phanerophytes, the temperate and the alpine of hemicryptophytes.The observations on leaf size indicate that with the exception of Pinus roxburghii forest, in all vegetation types, the species with microphylls are greater in number. In this region, the vegetation expression is evergreen, although the tree flora has a considerable content of deciduous elements. In all the forests, the flowering period in most of the trees is vernal.On the basis of relative density, the greatest proportions of adult trees in the Pinus roxburghii and Quercus lanuginosa forests are shade intolerant, while in the mixed and Quercus leucotrichophora forests maximum trees are intermediate in shade tolerance. With the exception of the Pinus roxburghii forest, all the forests exhibit the dominance of trees which are shade tolerant at the seedling stage. On the basis of relative density, all forest types, except for Pinus roxburghii forest, have 74.5 to 100% trees with the potentiality of vegetative reproduction.Financial support from the Indian Space Research Organisation, Banglore and University Grants Commission, New Delhi is gratefully acknowledged.     

Leaf growth pattern in evergreen and deciduous species of the Central Himalaya,India

Leaf growth patterns were investigated in 11 evergreen (with leaf life-spans of just more than 1 year) and 15 deciduous species, occurring along an elevational gradient of 600–2200 m elevation in the Central Himalaya. Records were made of the leaf initiation period, leaf population dynamics, leaf expansion, leaf mass changes, leaf longevity and related parameters. Species of both groups produced leaves at similar rates during March to April, the driest period of the year. Species of both groups had approximately fully developed foliage during the warm, wet period (mid-June to mid-September) of the monsoon. However, significant differences were found at group level in other characters: shoot length (19.5 cm per shoot for deciduous and 11.7 cm for evergreen species); leaf population per 10 cm shoot length (4.7 vs 15.0); leaf area (107.9 vs 41.4 cm²/ leaf); specific leaf mass (106.9 vs 191.3 g/m²); and leaf mass loss after the monsoon period, being rapid and higher (31.6%) in deciduous species and slow and limited in the evergreens (26.2%). However, species of the two groups showed considerable overlaps in the values of above characters. The evergreen species of the Central Himalaya resembled the deciduous species of the region more than the multi-year leaves of clearly evergreen species. The evergreens bear leaves throughout the year, but like deciduous species bear the cost of annual replacement of old leaves by new leaves. They seem to outcompete deciduous species by producing annually a greater mass of leaves of low-carbon cost (per unit leaf mass), which is capable of conducting photosynthesis all year round. A situation of less marked contrast between favourable and nonfavourable periods, with respect to temperature, seems to favour the leaf characters of the evergreens.     

Phenology of high-altitude plants of Kumaun in Central Himalaya,India

The various developmental stages of 184 species of high-altitude plants were studied during 1987 and 1988 in the Pindari glacial moraine area of Kumaun Himalaya in the Central Himalaya. The initiation of growth was synchronised with the beginning of the spring/or summer temperature rise and snowmelt. In this high-altitude zone, the peaks of various phenophases succeeded one after another over about 4 months from early June to October. It is suggested that the plants complete various growth cycles within a very short period of favourable conditions to ensure the survival of their progeny.     

Pollination Ecology of Pedicularis megalantha D. Don (Scrophulariaceae) in the Himachal Himalaya

Abstract In the summer of 1990, the pollination ecology of Pedicularis megalantha was studied in the montane-subalpine spruce-fir forest zone (2750-3050 m) on the north slope of Mt. Huttoo at Narkanda, Himachal Pradesh, in the Indian Himalaya. Its yellow, long-tubed, nectarless flower with a curled rostrum overarched by a broad, inverted lower corolla lip was pollinated exclusively by Bombus albopleuralis and B. tunicatus workers hanging inverted from the corolla and vibrating pollen from introrse anthers concealed within the galea and releasing pollen through a small ventral opening in the galea base. The stigma, protruding from the tip of the rostrum, contacted pollen deposited on the ventral side of the insect's thorax. Corbicular pollen loads from P. megalantha pollinators indicated equal numbers of monolectic and oligolectic foragers. P. megalantha appeared to suffer from competition for pollinators by Cynoglossum wallichii at one site but to be favored in a mixed plant community with nectariferous species offering a forage resource complementary to Pedicularis pollen. As in P. punctata , the long, nectarless corolla tube of P. megalantha appears to function in extending the rostrate vibration pollination mechanism beyond the plant's foliage, which would interfere with its function. It is not an adaptation for nectar-foraging lepidopteran pollinators. P. megalantha was also found to be a root hemiparasite.     

The vicarious differentiation of the alpineGalium serpylloides group (Rubiaceae), endemic to the W. Himalaya

Galium serpylloides agg. comprises a group of locally endemic, disjunct and vicarious taxa in the (sub)alpine zone of the W. Himalaya, from W to E:G. gymnopetalum, G. lahulense, G. serpylloides s. str.,G. saipalense, andG. nepalense. Four of these are new to science;G. serpylloides is newly typified. The main characters of the five species are compared and illustrated, their affinities and evolution are discussed, and a map of distribution is presented.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday.     

Reconstruction of heat index based on tree-ring width records of western Himalaya in India

To study climate variability/change, the tree-ring width index chronologies of two species (Cedrus deodara and Pinus roxburghii) of the western Himalaya was determined. The first principal component (PC1) prepared using the three-site tree-ring width chronologies of the western Himalaya was found to be negatively correlated with the heat index and positively with the Palmer Drought Severity Index (PDSI) and moisture index from February to May as representative of the regional climate. The correlation coefficient of PC1 with the heat index, PDSI, and moisture index for the period 1901–1988 was estimated to be −0.60, 0.37, and 0.59, respectively, which were highly significant at 0.1% level. The result shows that increasing the heat index may enhance transpiration and evaporation over the western Himalaya, which may cause insufficient moisture at the root zone of the trees. Based on the tree-ring data, the heat index of spring season (February–May) was reconstructed back to AD 1839. The reconstructed heat index showed the longest warm periods during 1952–1963 and 1966–1976 in the 20th century.     

Chemical Diversity in Indian Oregano (Origanum vulgare L.)

The terpenoid composition of the essential oils of 17 different populations of Origanum vulgare L., collected from wild populations and subsequently grown under similar conditions in the sub‐temperate region of the Western Himalaya, was studied. Analysis by GC (RI) and GC/MS allowed the identification of 51 components, representing 90.15 to 99.94% of the total oil. The two classes of the phenolic compounds and the monoterpenoids were predominant in all the essential oils. On the basis of the major constituents, i.e., marker compounds, and by comparison of the results with previous reports, new chemotypes could be identified. Principal component analysis was performed to determine the chemical variability within the different populations of O. vulgare collected and grown under similar conditions. Based on the marker compounds, six chemotypes with significant variations in their terpenoid profile were noticed within the 17 populations.     

Palaeogene marine stratigraphy in China

Palaeogene deposits are widespread in China and are potential sequences for locating stage boundaries. Most strata are non‐marine origin, but marine sediments are well exposed in Tibet, the Tarim Basin of Xinjiang, and the continental margin of East China Sea. Among them, the Tibetan Tethys can be recognized as a dominant marine area, including the Indian‐margin strata of the northern Tethys Himalaya and Asian‐margin strata of the Gangdese forearc basin. Continuous sequences are preserved in the Gamba–Tingri Basin of the north margin of the Indian Plate, where the Palaeogene sequence is divided into the Jidula, Zongpu, Zhepure and Zongpubei formations. Here, the marine sequence ranges from Danian to middle Priabonian (66–35 ma), and the stage boundaries are identified mostly by larger foraminiferal assemblages. The Paleocene/Eocene boundary is found between the Zongpu and Zhepure formations. The uppermost marine beds are from the top of the Zongpubei Formation (~35 ma), marking the end of Indian and Asian collision. In addition, the marine beds crop out along both sides of the Yarlong Zangbo Suture, where they show a deeper marine facies, yielding rich radiolarian fossils of Paleocene and Eocene. The Tarim Basin of Xinjiang is another important area of marine deposition. Here, marine Palaeogene strata are well exposed in the Southwest Tarim Depression and Kuqa Depression. They comprise mostly neritic and coastal lagoon facies of the Tethyan realm. Palaeontological evidence suggests that the Paleocene/Eocene boundary here is in middle of the Qimugen Formation. The Tarim Basin was largely drained by Late Oligocene. To the east, the marine offshore Palaeogene strata are widespread in the North Taiwan and East Zhejiang depressions of the continental shelf basin of East China Sea. Abundant fossils including foraminifera, calcareous nannofossils, ostracods, pollen and bivalves occur in the marine environment. Biostratigraphically, the sequence is well correlated with the international planktonic foraminiferal and nannofossil zonations.