Effects of grazing strategy on facultative grassland bird nesting on native grassland pastures of the Mid-South USA.

Understanding how livestock grazing strategies of native warm season grasses (NWSG) can impact facultative grassland bird nesting can provide insight for conservation efforts. We compared pre and post treatment effects of rotational grazing (ROT) and patch-burn grazing (PBG) for facultative grassland bird species nest success and nest-site selection on NWSG pastures at three Mid-South research sites. We established 14, 9.

Urea fertilization and grass species alter microbial nitrogen cycling capacity and activity in a C native grassland.

Soil microbial transformation of nitrogen (N) in nutrient-limited native C grasslands can be affected by N fertilization rate and C grass species. Here, we report dynamics of the population size (gene copy abundances) and activity (transcript copy abundances) of five functional genes involved in soil N cycling (, bacterial , , , and ) in a field experiment with two C grass species (switchgrass () and big bluestem ()) under three N fertilization rates (0, 67, and 202 kg N ha). Diazotroph () abundance and activity were not affected by N fertilization rate nor grass species.

Ammonia-oxidizing bacterial communities are affected by nitrogen fertilization and grass species in native C grassland soils.

Background: Fertilizer addition can contribute to nitrogen (N) losses from soil by affecting microbial populations responsible for nitrification. However, the effects of N fertilization on ammonia oxidizing bacteria under C perennial grasses in nutrient-poor grasslands are not well studied.

Methods: In this study, a field experiment was used to assess the effects of N fertilization rate (0, 67, and 202 kg N ha) and grass species (switchgrass () and big bluestem ()) on ammonia-oxidizing bacterial (AOB) communities in C grassland soils using quantitative PCR, quantitative reverse transcription-PCR, and high-throughput amplicon sequencing of genes.

Nitrogen Fertilization and Native C Grass Species Alter Abundance, Activity, and Diversity of Soil Diazotrophic Communities.

Native C grasses have become the preferred species for native perennial pastures and bioenergy production due to their high productivity under low soil nitrogen (N) status. One reason for their low N requirement is that C grasses may benefit from soil diazotrophs and promote biological N fixation. Our objective was to evaluate the impact of N fertilization rates (0, 67, and 202 kg N ha) and grass species (switchgrass [] and big bluestem []) on the abundance, activity, diversity, and community composition of soil diazotrophs over three agricultural seasons (grass green-up, initial harvest, and second harvest) in a field experiment in East Tennessee, United States.

Factors affecting availability for detection: An example using radio-collared Northern Bobwhite (Colinus virginianus).

Avian monitoring strategies are usually linked to bird singing or calling behavior. Individual availability for detection can change as a result of conspecific factors affecting bird behavior, though the magnitude of these effects is difficult to quantify. We evaluated behavioral and temporal factors affecting Northern Bobwhite (Colinus virginianus) breeding season individual availability for detection during three common survey times (3 min, 5 min, 10 min).