Context:
A recent study by researchers has highlighted the importance of the last fragments of tropical lowland forests in Assam by showing interactions between plants and fruit-eating birds in them.
Relevance:
GS-I: Geography (Physical Geography – Forest Resources and Natural Vegetation), GS-III: Environment and Ecology (Conservation of Environment and Ecology)
Dimensions of the Article:
- Tropical Lowland Humid Forest
- Tropical Lowland forests in India
- Recent Study on tropical lowland forests in Assam
Tropical Lowland Humid Forest
- Tropical Lowland Humid Forest occurs in the humid tropics, often within 10°of the equator, where rainfall is abundant and well-distributed throughout most or much of the year, including both wet evergreen and moist semi-evergreen forest.
- In general, a tropical rainforest climate can be defined as one with monthly mean temperatures of at least 18°C throughout the year, and an annual rainfall of at least 170 cm (and usually above 200 cm) and either no dry season or a short one of fewer than 4 consecutive months with <10 cm rainfall.
- Elevations range from lowland to submontane or premontane, with ranges from sea level to between 1000 and 1700 m depending on location.
- Evergreenness varies from completely evergreen to semi-evergreen seasonal forests, in which around 25% of the main canopy may be regularly deciduous.
- The vegetation is often species-rich, often lacking dominants, with the majority of the tree species of very low abundance.
Tropical Lowland forests in India
- The lowland rainforests of North Eastern India represent the westernmost limit of the rainforests north of the Tropic of Cancer.
- These forests, on the Shillong plateau, are akin to Whitmore’s ‘tropical lowland evergreen rainforest’ formation and exhibit striking similarities and conspicuous differences with the equatorial rainforests in Asia-Pacific as well as tropical seasonal rainforests in southwestern China near the Tropic of Cancer.
- Common attributes of the rainforests in Meghalaya with lowland rainforests found by a research paper:
- Deciduousness in evergreen physiognomy;
- Dominance of mega- and mesophanerophytic life-forms;
- Abundance of species with low frequency of occurrence (rare and aggregated species);
- Low proportional abundance of the abundant species
Recent Study on tropical lowland forests in Assam
- Small fruit eaters such as bulbuls and barbets “fed upon the highest number of fruits” in both, fragmented and contiguous forests and are crucial in seed dispersal in both these types of forests.
- the remaining patches of tropical lowland forests in Assam are very important for birds like the White-throated Brown Hornbill, which dispersed larger seeds that other birds were not able to.
- Fragmentation of habitats had resulted in reduced interactions between plants and frugivorous birds in forest patches. However, despite this, fragmented forest patches continued to harbour interactions and distinct ones at that, between frugivorous birds and plants.
-Source: Down to Earth Magazine
