Ecological implications and Conservation significance of liana abundance, and diversity in tropical forests

Abstract

Among the plant life-forms, lianas, the woody climbers remain relatively understudied than other life-forms. This presentation will focus on the ecological implications of liana abundance and diversity in tropical forests in the context of increasing liana abundance in tropics, climate change, forest disturbance and ever-increasing tropical deforestation, forest fragmentation and the consequent edge creation and liana colonization. Conservation significance of lianas will be addressed from the context of lianas as dependent life-form, seeking host trees, dependence on fauna for dispersal, especially in Indian tropics, role in forest functional ecology and their economic importance, as a source of food, medicine and ornamentals etc. Lianas are conspicuous feature of tropical forests and constitute an important floristic, structural and functional component of tropical forests. They contribute significantly to the diversity of tropical forests 25% of the woody stem density and species diversity in many tropical forests, but 50% in Peninsular Indian forests. Recent research works have proved the increasingly important role of lianas in forest regeneration, biodiversity and ecosystem-level processes such as whole-forest transpiration and carbon sequestration, particularly in the tropics.

A total of at least 133 families include at least a few climbers. Largest climbing genera include Dioscorea (600 species), Ipomoea (500), Cissus (350) Philodendron (275), Combretum (230), Salacia (150), Artabotrys and Peperomia (100 species each). Lianas have evolved a number of climbing mechanisms - Stem twiners, Stragglers, Tendril climbers, Hook climbers, Root climbers, Grapnel-like climbers. Twiners predominantly (95%) twine in anticlockwise direction. Liana abundance is a bio-indicator of disturbance. Results of Liana diversity inventoried in various peninsular Indian forests will be discussed. In many tropical forests of peninsular India, liana and tree diversity ratio is approximately 1:2. As the climate of much of the tropics is becoming drier, an increase in both liana abundance and their proportion is expected in future decades. Changes to the tropical climate in the coming century may not strongly affect lianas directly, but could have very substantial indirect effects via changes in tree community structure and dynamics and disperser limitations, particularly in peninsular Indian forests wherein animal dispersal is prevalent and hence, a holistic approach in liana conservation will be emphasized.

Speaker

Dr. N. Parthasarathy, Department of Ecology and Environmental Sciences, Pondicherry University, Puducherry – 605 014.

Organisers

Department of Ecology, French Institute of Pondicherry.

Venue

Jawaharlal Nehru Conference Hall, French Institute of Pondicherry, 11, Saint Louis Street, Pondicherry - 605 001

Time

4.30 pm