نتایج جستجو برای: forest floor
تعداد نتایج: 137489 فیلتر نتایج به سال:
Boreal forests comprise 73% of the world's coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time ...
Spatial and temporal variation in the below-canopy light environment of tropical forests is not well known and its measurement is technically challenging. Distributions of gap and understory areas in forests are likewise little known because of the resource requirements of forest structural censuses and a lack of consensus over how gaps should be defined. A basic model of forest structure, base...
In a Neotropical moist forest at Barro Colorado Island, Panama, 6'3C values of CO2 in air and (13C values of leaf tissue exhibit parallel patterns of variation between the forest floor and the canopy. During the daytime, 613C values of CO2 from air sampled at 1 m and 0.5 m were significantly less than that at 25 m. Based on mass balance equations, up to 18% of the CO2 in air at 0.5 m above the ...
Spatial and temporal variation in the below-canopy light environment of tropical forests is not well known and its measurement is technically challenging. Distributions of gap and understory areas in forests are likewise little known because of the resource requirements of forest structural censuses and a lack of consensus over how gaps should be defined. A basic model of forest structure, base...
Information is lacking on ecosystem effects of understory burning in mesic mixed-oak (Quercus spp.) forests of the southern Appalachians. Native Americans used periodic fires in these forests for driving game and opening the forest. In April 1998, we conducted a lowto moderate-intensity fire in a cove–hardwood forest in the Nantahala National Forest, western North Carolina. In March 1998, befor...
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