SEASONAL-CHANGES IN STEM DIAMETER AND LEAF DEVELOPMENT IN A TROPICAL MONTANE FOREST

被引：7

作者：

SINGH, SP

RALHAN, PK

UPADHYAY, VP

NEGI, GCS

机构：

[1] Department of Botany, Kumaun University, Naini Tal

[2] Department of Forestry and Natural Resources, Punjab Agricultural University, Ludhiana

来源：

JOURNAL OF VEGETATION SCIENCE | 1990年 / 1卷 / 02期

关键词：

Central Himalayas; Deciduous; Evergreen; Quercus; Seasonally dry climate; Water stress;

D O I：

10.2307/3235655

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

Abstract. Seasonal patterns of stem diameter changes in evergreen and deciduous species of a tropical montane forest in the Central Himalayas (300–2250 m a.s.l.) were investigated in relation to leaf development. Ca. 75 % of the annual rainfall in this region occurs in a short period, from mid‐June to mid‐September and the remaining months are dry. It was assumed that changes in stem diameter are correlated with changes in water stress. Each evergreen species could be characterized by leaf longevity of about one year; each species showed pronounced summer leaf drop and simultaneous new leaf formation. Winter stem shrinkage was more pronounced in deciduous species than in evergreen ones. The deciduous species also showed a greater proportional loss of leaf mass (before abscission) than the evergreen species. Winter leaf fall in deciduous species was related to the pronounced stem shrinkage. The leaf fall enabled these species to control further water loss. Being more resistant to desiccation, the evergreen species retained their leaves throughout the winter but showed gradual loss of leaf mass, presumably in order to control water loss. In all species, leaf expansion was completed before the onset of the rainy season, when water stress was high. This strategy has definite advantages in a climate with a monsoon pattern of rainfall. Evergreen species, showing pronounced leaf drop in summer, have advantages over deciduous species; hence their preponderance in the region. 1990 IAVS ‐ the International Association of Vegetation Science

引用

页码：165 / 172

页数：8

共 26 条

[11]

Meinzer F., Seymour V., Goldstein G., Water balance in developing leaves of four tropical savanna woody species, Oecologia, 60, pp. 237-243, (1983)

[12]

Murphy P.G., Lugo A.E., Ecology of tropical dry forest, Annual Review of Ecology and Systematics, 17, pp. 67-88, (1986)

[13]

Osmaston A.E., A forest flora of Kumaun, (1926)

[14]

Parker J., Drought resistance in woody plants, Bot. Rev., 22, (1956)

[15]

Ralhan P.K., Khanna R.K., Singh S.P., Singh J.S., Phenological characteristics of the tree layer of Kumaun Himalayan forests, Vegetatio, 60, pp. 91-101, (1985)

[16]

Ralhan P.K., Khanna R.K., Singh S.P., Singh J.S., Certain phenological characters of the shrub layer of Kumaun Himalayan forests, Vegetatio, 63, pp. 113-120, (1985)

[17]

Ralhan P.K., Singh S.P., Dynamics of nutrients and leaf mass in Central Himalayan forest trees and shrubs, Ecology, 68, pp. 1974-1983, (1987)

[18]

Reich P.B., Borchert R., Phenology and ecophysiology of the tropical tree Tabebuia neochrysantha (Bignoniaceae)., Ecology, 63, pp. 294-299, (1982)

[19]

Singh J.S., Singh S.P., Forest vegetation of the Himalaya, Bot. Rev., 53, pp. 80-192, (1987)

[20]

Singh S.P., Khanna R.K., Singh J.S., Accumulation in wood: A nutrient conserving strategy of tropical forests, Environ. Conserv., 12, pp. 170-173, (1985)

← 1 2 3 →