InvasiveAndropogon gayanus(gamba grass) is an ecosystem transformer of nitrogen relations in Australian savanna

Invasive Andropogon gayanus (gamba grass) is an ecosystem transformer of nitrogen relations in Australian savanna.

Invasion by the African grass Andropogon gayanus is drastically altering the understory structure of oligotrophic savannas in tropical Australia. We compared nitrogen (N) relations and phenology of A. gayanus and native grasses to examine the impact of invasion on N cycling and to determine possible reasons for invasiveness of A. gayanus. Andropogon gayanus produced up to 10 and four times more...

Determinants of flammability in savanna grass species

Tropical grasses fuel the majority of fires on Earth. In fire-prone landscapes, enhanced flammability may be adaptive for grasses via the maintenance of an open canopy and an increase in spatiotemporal opportunities for recruitment and regeneration. In addition, by burning intensely but briefly, high flammability may protect resprouting buds from lethal temperatures. Despite these potential ben...

Preferential Production and Transport of Grass-Derived Pyrogenic Carbon in NE-Australian Savanna Ecosystems

Soil carbon and nitrogen storage in response to fire in a temperate mixed-grass savanna.

Vegetation fires may alter the quantity and quality of organic matter inputs to soil, rates of organic matter decay, and environmental factors that influence those processes. However, few studies have evaluated the impacts of this land management technique on soil organic carbon (SOC) and total N in grasslands and savannas. We evaluated the impact of repeated fires and their season of occurrenc...

Relations between bacterial nitrogen metabolism and growth efficiency in an estuarine and an open-water ecosystem

Bacterial uptake or release of dissolved nitrogen compounds (amino nitrogen, urea, ammonium and nitrate) were examined in 0.8 pm filtered water from an estuary (Santa Rosa Sound [SRS], northwestern Florida) and an open-water location in the Gulf of Mexico (GM). The bacterial nutrient dynamics were related to oxygen consumption and activity of enzymes involved in nitrogen assimilation (glutamate...