Presentation on theme: "PHOTO: Burkhard Schmidt-Brücken Institute of Material Science/TU Dresden COLOR: Christian Schurig/ UFZ Hyphomicrobium bacteria (yellow) grow on solid surfaces."— Presentation transcript:
PHOTO: Burkhard Schmidt-Brücken Institute of Material Science/TU Dresden COLOR: Christian Schurig/ UFZ Hyphomicrobium bacteria (yellow) grow on solid surfaces & grains. When bacteria cells die, they deform or fragment until only cell envelopes remain. Small fragment shells (red) form micro-particle matrix in soils. Contributions of bacteria remnants to soil fertility are underestimated It was assumed Soil Organic Matter is mostly decomposed plant matter which directly converts to humic substances Lab experiments and field tests refute this. Easily degradable plant matter is converted to microbe biomass, which then provides source material to Soil Organic Matter 40% of microbe biomass is converted to Soil Organic Matter Remains of dead bacteria are far greater in soils than previously assumed. Soil Organic Matter is the largest fraction of carbon in the biosphere, and plays key roles in soil fertility and agricultural yields. Microbes also a key factor to control CO 2 concentration in the atmosphere. Climatic change can be slowed or accelerated, according to soil management Research report in professional journal Biogeochemistry Helmholtz Centre for Environmental Research, Switzerland Technical University of Dresden, Germany University of Stockholm, Sweden Max Planck Institute for Developmental Biology, Germany Leibniz University, Hanover, Germany Microbes & Climate Biochar Properties Most plant debris in fertile soil is rapidly processed by microbes (bacteria) leading to more bacteria and thus, more cell fragments. This results in more Soil Organic Matter. Although most organic carbon is produced mainly by plants, a large part is residues of bacteria and fungi. This underscores the importance of bacteria in all types of soil. Further, microbes are important for global climate: Decay of organic matter results in mineralization + CO 2 + H 2 O CO 2 escaping annually to the atmosphere from decaying Soil Organic Matter is in the same range of scale as annual greenhouse gas emissions. Thus, progress in climate protection isn’t achievable without first protecting soil.
residential refuges for micro-orgamisms Spores of G. Margarita germination higher than on soil biochar provides preferred habitat for soil microbes Bacteria & Biochar Biochar Properties PHOTO: Makato Ogawa, Japan, 1991 Dr. Makato Ogawa 1991
Bacteria populations show sharp increase after charcoal addition 3-foldincrease Biochar Properties Bacteria & Biochar Beijerinckia & Ogawa 1992
effect on soybean root growth & nodules PHOTO: M. Ogawa, Kansai Environmental, Japan Nitrogen-fixing Bacteria Biochar Properties
Despite a surge of research recently, challenges to soil biologists remain daunting. Even basic biodiversity below ground—species diversity and distribution —remains far more obscure than for life above the soil surface. Soil fungi are a case in point: key component of soil ecosystems, its global species diversity has been estimated by various methods. Fungi communities are highly structured, based on pH, soil horizon, species, and other conditions of the understory plant community. Fungi study in Alaskan boreal forest soils suggests previous estimates of diversity at.5 to 1.5 million species need to be revised upward. DNA data from fungal samples found over 1000 discrete fungal taxa— many more than estimated from non-molecular data. A fungus:plant ratio of 17:1 extrapolates to at least 6 million fungal species globally. This suggests 98% of fungi have yet to be discovered. Diversity Down Below Andrew M. Sugden Ecology: Ecol. Monogr. 84, 3 (2014) Microbial Colonization Biochar Properties