Amazon trees grow fastest in dry season
Sunshine is better growth-booster than water for ancient forest.
Some trees in the Amazon rainforest grow fastest not in the wet season, but in the dry, sunny part of the year, researchers have found. The discovery underlines the importance of preserving old-growth forest that is likely to be more resistant to drought.
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Comments
Has anyone ever estimated the percentage of Earth's oxygen produced in the Amazon Rain forest? Carbon absorbed? Should we Westerners consider paying Brazil an 'oxygen resource' fund to protect "their" rain forests?
Posted by: Richard Griest | March 23, 2006 05:24 AM
doubtly think that 's unbelievable,'cauce we can find the contrast show by studying tree ring .if it's true,so what about tree ring
Posted by: george | March 23, 2006 06:13 AM
Protecting the Rain forest of the Amazona as well as other areas of the tropics should a task that all of us have to do. Costa Rica is giving an example as how to protect the remaning rain forest. If we pay money to the poorest country to protect their rain forest we will be really making global the effort to make this world a better place to live. The rich countries of the world should spend some of their budget in protecting our tropical rain forest since we are offering an enviromental service for the earth.
Posted by: David Guadamuz | March 27, 2006 09:01 PM
Protecting the Rain forest of the Amazona as well as other areas of the tropics should be a task for all of us. Costa Rica is giving an example as how to protect the remaning rain forest. If we pay money to the poorest the countries to protect their rain forest we will be really making a global the effort to make this world a better place to live. The rich countries of the world should spend some of their budget in protecting our tropical rain forest since we are offering an enviromental service for the earth and we are clear cutting our forest for needs, not for justpure destruction of it. David Guadamuz www.grupoice.com Costa Rica
Posted by: David Guadamuz | March 27, 2006 09:06 PM
The discovery of Huete et al. does not sound too exciting to me. 1. The flush of trees during the dry season is a long known phenomenon. 2. Secondary growth forests houses different tree species than "old growth" forests. 3. Even during the dry season, water might not be the limiting factor in varios regions of the Amazon. 4. Also in African rain forests light is quite limited during the rainy season. 5. Evergreen trees are not uncommon in tropical forests. So what's new, when they see green trees on satelite images during the dry season?
Posted by: Falk-Juri Knauft | March 28, 2006 06:43 AM
i have also done a lot of work regarding analyzing the phenology of tropical biomes in the amazon and in parts of central africa using satellite images. WEll considering the fact that vegetation indices like Leaf Area Index and Enhanced Vegetation Index provide us with the right vegetation spectrum, it was amazing to look into the greening in dry season..and especially when there is no water stress in these regions. The deep root hypothesis frm Huete et. al really holds true for these tropical evergreen forests. Soil moisture retention capacity shows constant trend throughout the year even if there is decreased precipitation. Also the effective utilization of diffused radiation plays an important role for plants to efficiently undergo photosynthesis rather than harnessing direct radiation. The important result to discuss is as to why the amazonia and parts of the indonesian rainforests shows greening in dry season, as compared to the central african rainforests, which more or less follows the precipitation patterns. Species dependency on climate factors is a must to understand these effects. Validation measurements are needed.
Posted by: sangram ganguly | April 26, 2006 05:57 AM