Leaf classes, foliar phenology and life forms of selected woody species from the tropical forests of central and southern Eastern Ghats, India

A checklist of selected woody species of Angiosperms is provided with the aim of classifying their life forms, foliar phenology and leaf classes from the tropical forests of central and southern Eastern Ghats, India. Though there are checklists available for the plants of the Eastern Ghats, a comprehensive listing of quantitative foliar measurements as done in other parts of the world, leading to valuable inputs for Plant Functional Type (PFT) classification, has not thus far been done for this key biogeographic zone of India. The list, gathered from 388 individual plants through the study area, encompasses 156 species and 3 infraspecific taxa which belong to 116 genera and 50 families. Of the total 159 taxa, 83 are evergreen and 76 are deciduous. 135 taxa are trees, 13 are shrubs 10 are climbing shrubs and one hemiparasite. Among the leaf classes of species, mesophyll dominated with 87 species, followed by notophyll (39), microphyll (24) and macrophyll (9). Hence, quantitative leaf trait measurements for selected woody species and the methodology for such studies in the tropics is the unique contribution of the present paper to the existing state-of-the-art.

Effects of CO2 in interaction with temperature and soil fertility on the foliar phenology of alder, birch, and maple seedlings

The foliar phenology of potted 1-year-old seedlings of alder (Alnus hirsuta Turcz.), maple (Acer mono Maxim.), and birch (Betula platyphylla Sukatch. var. japonica Hara) was observed from May to September in eight growth environments: factorial combinations of temperatures (light:dark, 30:20 °C and 26:16 °C), CO2 level (70 and 36 Pa), and nutrient regime (high versus low levels of fertilization). Seedlings grown at high fertility always had more leaves, and under high CO2, shed leaves slightly later than seedlings grown at low fertility. Except for maple, production of newly formed shoots and leaves was accelerated by high CO2. In maple, high CO2 only increased the number of flushes of the leader shoot. Alder and birch accelerated sylleptic shoot and leaf production at high CO2 in fertile conditions. The production of new leaves by alder grown at high CO2 and low fertility was almost the same as that grown under normal CO2, at high fertility. At high CO2, the timing of winter bud formation of monopodial alder and maple was delayed, while that of sympodial birch was almost the same as at ambient CO2. Key words: foliar phenology, elevated atmospheric CO2 and temperature, monopodial versus sympodial growth, nutrient levels, winter bud formation, global change.

Patterns of leaf phenology in forest understory

Foliar phenologies of forest understory plants were categorized, and the distribution pattern of leaf habit was examined among different forest environments. Various patterns of foliar phenology were found, especially in herbaceous plants. In addition to the seasonal light regime controlled by the phenology of canopy trees, differences in the length of period with snow cover led to the divergence. Perennial-leaved plants predominate in intensely shaded habitats while annual-leaved plants are more abundant in less shaded habitats. The shade tolerance of perenniel-leaved plants can be considered a preadaptation to snow tolerance. In contrast with the perennial-leaved plants, biennial-leaved plants with leaves overwintering 1 year appear to be favored in euphotic habitats with high insulation both in spring and in autumn. These species are effective competitors in spring because of rapid emergence of current leaves, probably through retranslocation of resources accumulated in the previous year. Another adaptive trait is found in heteroptic plants simultaneously having summer-green leaves and overwintering leaves; these types of leaves seem to function in predictable and quite different environments in a year. Key words: foliar phenology, growth form, light resource, overwintering leaf, snow cover.