Filters: Tags: N uptake (X)3 results (158ms)
Past studies of plant?microbe interactions in the alpine nitrogen cycle have revealed a seasonal separation of N use, with plants absorbing N primarily during the summer months and microbes immobilizing N primarily during the autumn months. On the basis of these studies, it has been concluded that competition for N between plants and microbes is minimized along this seasonal gradient. In this study, we examined more deeply the links between microbial population dynamics and plant N availability in an alpine dry meadow. We conducted a year-round ?eld study and per formed experiments on isolated soil microorganisms. Based on previous work in this ecosystem, we hypothesized that microbial biomass would decline before...
Categories: Publication; Types: Citation, Journal Citation; Tags: Ecology, Kobresia myosuroides, N uptake, alpine tundra, microbial population dynamics,
Growth and partitioning in Pascopyrum smithii (C3) and Bouteloua gracilis (C4) as influenced by carbon dioxide and temperature
This study investigated how CO2and temperature affect dry weight (d.wt) accumulation, total nonstructural carbohydrate (TNC) concentration, and partitioning of C and N among organs of two important grasses of the shortgrass steppe,Pascopyrum smithii Rydb. (C3) andBouteloua gracilis(H.B.K.) Lag. ex Steud. (C4). Treatment combinations comprised two temperatures (20 and 35�C) at two concentrations of CO2(380 and 750 ?mol mol-1), and two additional temperatures of 25 and 30�C at 750 ?mol mol-1CO2. Plants were maintained under favourable nutrient and soil moisture and harvested following 21, 35, and 49d of treatment. CO2-induced growth enhancements were greatest at temperatures considered favourable for growth of these...
Categories: Publication; Types: Citation, Journal Citation; Tags: Annals of Botany, Bouteloua gracilis, N uptake, Pascopyrum smithii, acclimation to CO2,
An experiment was conducted to determine if growth and biomass responsesof the annual grass Bromus tectorum are affected by themagnitude and timing of nitrogen (N) pulses and if these responses areinfluenced by different perennial neighbor species. Nitrogen(NH4:NO3) was applied in three pulse treatments of varyinginterpulse length (3-d, 9-d, or 21-d between N additions). The total amount of Nadded was the same among treatments; hence, both the frequency and magnitude ofN pulses varied (i.e., the longer the interpulse period,the greater the amount of N added for a single pulse).Bromus showed little response to the different N-pulsetreatments. The only characteristic that varied among pulse treatments wasspecific...
Categories: Publication; Types: Citation, Journal Citation; Tags: Great Basin vegetation, N uptake, Plant Ecology, nutrient pulse