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Full-Text Articles in Life Sciences
Breaking The Enzymatic Latch: Impacts Of Reducing Conditions On Hydrolytic Enzyme Activity In Tropical Forest Soils, Steven J. Hall, Jonathan Treffkorn, Whendee L. Silver
Breaking The Enzymatic Latch: Impacts Of Reducing Conditions On Hydrolytic Enzyme Activity In Tropical Forest Soils, Steven J. Hall, Jonathan Treffkorn, Whendee L. Silver
Steven J. Hall
The enzymatic latch hypothesis proposes that oxygen (O2) limitation promotes wetland carbon (C) storage by indirectly decreasing the activities of hydrolytic enzymes that decompose organic matter. Humid tropical forest soils are often characterized by low and fluctuating redox conditions and harbor a large pool of organic matter, yet they also have the fastest decomposition rates globally. We tested the enzymatic latch hypothesis across a soil O2 gradient in the Luquillo Experimental Forest, Puerto Rico, USA. Enzyme activities expressed on a soil mass basis did not systematically decline across a landscape O2 gradient, nor did phenolics accumulate, the proposed mechanism of …
Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown
Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown
Michael J Weber Dr
Resource pulses and subsidies can supply ecosystems with an important source of nutrients that supports additional productivity at multiple trophic levels. Common carp Cyprinus carpio provide ecosystems with a continuous nutrient subsidy through bioturbation and excretion but may also initiate a nutrient pulse through carcass decomposition. We examined how continuous (common carp foraging and excretion), pulsed (carcass decomposition) and disrupted (carp introduced and then removed) nutrient subsidies differed in their ability to alter nutrient availability, ecosystem productivity and stability and energy flow. Nitrogen and phosphorus availability and primary production were highest in pulsed, intermediate in continuous and lowest for disrupted …
Insect-Damaged Corn Stalks Decompose At Rates Similar To Bt-Protected, Non-Damaged Corn Stalks, R. Michael Lehman, Shannon L. Osborne, Deirdre A. Prischmann-Voldseth, Kurt A. Rosentrater
Insect-Damaged Corn Stalks Decompose At Rates Similar To Bt-Protected, Non-Damaged Corn Stalks, R. Michael Lehman, Shannon L. Osborne, Deirdre A. Prischmann-Voldseth, Kurt A. Rosentrater
Kurt A. Rosentrater
The relative decomposability of corn (Zea mays L.) residues from insect (Bt)-protected hybrids and conventional hybrids cultivated under insect pressure was investigated in two studies. Above-ground biomass, residue macromolecular composition, and stalk physical strength were also measured. In the first decomposition study, chopped residues (stalks and leaves) were used from a corn rootworm-protected (Cry3Bb1) hybrid and its non-Bt near isoline that were grown in replicated plots infested with corn rootworms (Diabrotica spp.). In the second study, residue (intact stalk sections) was used from three European corn borer (ECB, Ostrinia nubilalis Hübner)-resistant (Cry1Ab) hybrids representing different seed manufacturer/maturity date series, their …