The action of continuous logging and re-growing tropical forests to provide timber is decreasing the rates of essential nutrients in the soils. Such a thing might also limit future forest increase and revival, according to recent research.
It might increase, too, concerns about the long-term sustainability of logging in the tropical areas. Trees of recovering tropical forests were discovered to develop stronger leaves, with weaker concentrations of the nutrients nitrogen and phosphorus than trees of old-growth forests.
Those two elements are very significant for tree and plant growth. The occurring indicates that many periods of logging and recovery irreversibly erase phosphorus from the forest system, and are also making the component towards ecological limits.
Dr. Tim Swinfield, a plant scientist from the University of Cambridge Conservation Research Institute, detailed: “Old-growth tropical forests that have been the same for millions of years are now changing irreversibly due to repeated logging.”
Soil nutrients, including phosphorus, arise from rocks and are carried by trees through their roots. Cutting down the trees means losing those nutrients through gas emissions, soil decay, and elimination of nutrients in the extracted timber.
Deteriorated soils reveal that tropical forests might never recover from logging
Researchers approximate that up to 30 % of the available phosphorus in the soil is being eliminated from tropical forest systems by repeated logging. Dr. Swinfield added: “We see that as the logged forests start recovering, they’re actually diverging from the old-growth forests in terms of their leaf chemistry and possibly also species composition, as the amount of available nutrients goes down.”
The team of researchers developed a high-definition system of images of a forest area in north-eastern Borneo utilizing LIDAR-assisted imagining spectroscopy from an aircraft. Such a method of remote sensing, with a laser scanner and an advanced camera, succeeded in getting hundreds of measurements across the light spectrum.
Researchers had also added to that some nutrient measurement details from 700 individual trees in the forest. They got intriguing results and could map the concentrations of nutrients in the trees’ leaves over a place with a continuously logging situation and from an old-growth forest, as well.
The research is the first-ever to study how leaf function variates in response to logging. It also indicates that each consecutive harvest decrees the rate of nutrients in the system, and recently grown trees have to accommodate to preserve the rare resources available to them.