Carbon Stabilisation in Tropical Ecosystem

Abstract

Carbon (C) cycling and sequestration are two paradigms in global C stabilisation. On one part, continuous biogeochemical cycling of carbonaceous C (organic C) and C dioxide-C (CO2-C) are all vital and essential for life on the planet earth. There can be no life without C, in addition to hydrogen, oxygen and other elements known to science. The problem lies with excess CO₂-C which remains in relative gaseous phase in the environment of soil, water and air. The global limit of CO₂-C continues to rise in the era of agricultural, industrial and human civilisations that depend primarily on burning of fossil fuel, coupled with other anthropogenic activities like bush burning, deforestation, logging, gas flaring in crude oil exploration and wastes disposal. These have come with consequent environmental consequences, namely, global warming, climate change, melting of arctic ice, rise in sea level, flooding, tsunami, acidification, acid rain, desertification, pollution and habitat degradation/losses. To mitigate C excesses in the environment, scientists and researchers have tried several schemes/approaches in C sink, popularly referred to as “sequestration”. The rate of sequestration in atmosphere, lithosphere and hydrosphere depends on the available methods and resources. In atmosphere, C-sequestrations have involved reforestation or afforestation to securely capture CO₂-C and store as nutrients in plant parts in the form of cellulose, hemicelluloses, starch, carbohydrate and glucose. In lithosphere, C-sequestrations have involved organic matter amendments/deposition, alley farming, silviculture and agroforestry. In hydrosphere, C-sequestrations have involved ocean fertigation with iron (Fe⁺⁺) fillings required by phytoplankton as nutrients. The limitation for atmospheric sink lies on global deforestation/logging for agriculture and timber, while that of lithospheric sequestration lies on high-input agriculture that makes use of inorganic fertilisers, agrochemicals and agricultural mechanisation/processing/storage that depends on burning of fossil fuel, bush burning and bush clearing for land preparation/agricultural activities. The limitation of hydrospheric sequestration lies on cost, availability and affordability of Fe⁺⁺ fillings. Whichever method of C sink, successes and failures come with global welcome as scientists, agriculturists and researchers strive to test, develop and adapt all local, regional, national and international options, including integrated approaches/methods/formulas. The chapter “Carbon stabilisation in tropical ecosystem” is geared towards highlighting the importance of carbon sink in our ecosystem. The methods and systems of C sink or storage vary from one location to another. But the idea remains that excess gaseous carbon dioxide-C in the environment is very inimical to environmental health, and all options required for their sink and stabilisation in the environment should be accelerated all over the world to avoid what this chapter likens to “carbon holocaust”.