S. P. Vasudeva , T. S. Sareen

Abstract

Dalbergia sissoo flowers were pollinated by honey bees, beetles, butterflies and thrips. These insects except thrips, primarily affect cross-pollination, but self-pollinations were also caused by them. Thrips mainly brought about self-pollinations as they were mostly confined inside the flowers. The anthesis, dehiscence of anthers, stigma receptivity and pollinator activity showed synchronised diurnal rhythm which ensures effective pollination.

Keywords

Pollination Biology, Dalbergia Sissoo Roxb., Chandigarh, Honey Bees, Beetles,
Butterflies.

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S. P. Vasudeva , T. S. Sareen

Abstract

Dalbergia sissoo has flowering season of two months and the peak flowering period was for a week. The anthesis, dehiscence of anthers, stigma receptivity and pollinator activity showed synchronised diurnal rhythm. Flowers were pollinated by honey bees, beetles, butterflies and thrips. Despite the deep penetration of the self pollen tubes only 6% of selfed flowers produced fruits (against 44% in cross pollinated). This is due to the presence of self-incompatibility which is assessed to be of the gametophytic type. The low seed production helped in efficient dispersal of pods due to decreased wing loading of pods. It also helped in post dispersal establishment due to lack of competition between fewer genetically related seeds in a pod. Dispersal of seeds occurred through the agency of wind, birds and water. The abortion of flowers and immature fruits was common in Dalbergia sissoo. The fruit set in nature was 15% while the remaining 85 % flowers aborted. The fruit formation following deliberate selfing was 6 % in contrast to 44% from deliberate cross-pollination. Post zygotic factors have primarily been implicated to explain the abortion of fruits in D. sissoo. The average seed production was 1.30 formed from an average of 5 ovules. The mature brown pod was 1-3 seeded and rarely 4 seeded. Seed abortion was observed in 74% of cases with only 26% cases of the ovules developing into mature seeds. The distal most ovule developed into mature seed in 75% cases. Seed abortions were probably due to the dominant distal most ovule starving the other proximal ovules.

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S. P. Vasudeva ¹

Affiliations
1 Himachal Pradesh, IN

Abstract

There is no clear and comprehensive definition of the term forest in Indian Forest Act, 1927 or any other legislative tool of the country. Accordingly, attempt has been made to define forest based on what is contained in various dictionaries and encyclopedia, functions these perform, what is contained in various Acts related to forests and forestry in India and work being undertaken by Forest Survey of India. The different aspects taken into account by various countries and Multi-lateral organisations while defining forest has also been considered. The definition thus arrived at is based on canopy cover/density and height of trees along with nature of species contained in that area of land. Such a definition of forest would help in conservation of forests, utilizing their socio-economic as well as environmental potential, in tackling the menace of climate change and other environmental hazards. It will take us towards fast track socioeconomic development of the country which sometimes gets hindered due to faulty understanding and interpretation of the term forest and its application due to regulatory Forest Acts.

Keywords

Clean Development Mechanism (CDM), United Nations Framework of Convention on Climate Change (UNFCCC), Non Timber Forest Products (NTFP), Afforestation, Reforestation.

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