Msc student from Rio de Janeiro State University, João Souza, is developing his fieldwork at REGUA for his research project aiming to establish how fragmented areas in the Atlantic Forest could affect secondary production of tadpoles.
João also wishes to demonstrate through his research the important role of isolated mother trees in helping to maintain natural ecosystem processes. As part of these ecosystem processes he is specifically looking at net secondary yeld, however it is important to remember the previous step – raw primary yeld. Terrestrial ecosystems rely on the sun’s energy to support the growth and metabolism of their resident organisms. Plants are known for being biomass factories powered by sunlight, supplying organisms higher up the food chain with energy and the structural “building blocks of life”. Autotrophs are terrestrial prime yeld producers: organisms that manufacture, through photosynthesis, new organic molecules (carbohydrates and lipids) from raw inorganic materials (CO2, water, mineral nutrients).
The energy from the sun is stored on the newly created chemical bonds, being then source of energy to heterotroph organisms. Heterotrophs are secondary yeld producers, rather consuming than producing organic molecules.
Net secondary yeld (NSY) historically represents the formation of living biomass of a heterotrophic population or group of populations over some period of time. It’s known that not all food eaten by an individual is converted into new animal biomass (NSY), only a fraction of the material ingested is assimilated from the digestive tract; the remainder passes out as feces. Of the material assimilated, only a fraction contributes to growth of an individual’s mass or to reproduction — both of which ultimately represent net yeld. Most of the rest is consumed by normal methabolims (like respiration).
João’s research may supply important data highlighting the importance of conserving vegetation fragments – even standing trees – to help maintain essential natural ecosystem processes like NSY. He also wishes to understand how the group of anurans, one of the largest vertebrate taxa with many threatened species, is affected by the loss of vegetation.