An Empirical Comparison of Beta Diversity Indices in Establishing Prairies

Whittaker (1960, 1972) first proposed the idea that species diversity has spatial components, with alpha diversity estimating diversity within individual stands (or communities) and beta diversity estimating the number of community types in an area (or in Whittaker’s terminology, ‘‘differentiation of communities along gradients’’). These two values combined make up gamma diversity. Beta diversity is important because it provides the conceptual link between local and regional diversity, more directly measures how soil types, disturbance, and dispersal affect diversity, and is helpful in understanding why species loss is sometimes smaller than predicted by theory (Wilsey et al. 2005). Many interesting and longstanding questions are applied across scales, such as how much diversity is found within islands vs. across islands? Is the number of habitat types (i.e., beta) within islands key to explaining diversity at larger scales or is it the greater population sizes found on large islands? Furthermore, a consideration of both alpha and beta is necessary for understanding how diversity arises and is maintained in diverse systems. For example, in the northern Great Plains, we have found that remnant prairies can contain over 120 plant species within a small area (Wilsey et al. 2005); this occurs because of high diversity at the neighborhood scale where 20–25 species are found per square meter (Martin et al. 2005), and from species accumulation across neighborhoods (i.e., beta)

Native cover crops and timing of planting: Effects on 15N uptake, weed invasion and prairie establishment

Cover crops have been used for several purposes in prairie restorations. This project looked at whether the assumed benefits are supported by research results

Dominant Grass Effects on Diversity and Functioning of Restored Grassland

Native grasslands provide a multitude of benefits to society including forage production, wildlife habitat, and nutrient and CO2 uptake and storage. There has been continuing interest within the conservation community in restoring grasslands to maximize these multiple benefits. In addition to achieving the most common objectives of reducing soil erosion and increasing organic carbon and nutrient availabilities, restored grasslands also produce important wildlife habitat, and they have the potential to uptake and store greenhouse gases like CO2 . Grassland plantings have been found to increase game and non-game bird abundance and diversity and to improve deer habitat

Importance of Species Replication in Understanding Plant Invasions into North American Grasslands

The global homogenization of the Earth’s biota is expected to increase due to the increase in movement of people and goods between regions, and many introduced species are having a negative economic impact. The increase of introduced species can be thought of as a major global change, because ecosystems throughout the world are now impacted by exotics [1, 2]. Grasslands, which cover roughly 25% of the globe, contain perhaps the most disrupted and homogenized communities in the world. Native grasslands have been lost because of land conversion, and native species have been replaced or displaced with introduced grasses and legumes. Many species were intentionally introduced during the early 20th century to prevent erosion or to improve grazing, and many have undoubtedly done so. However, as management objectives for grasslands have expanded to include wildlife habitat, biodiversity, and C sequestration, it has become critical to understand how introduced species are affecting these new objectives as well. For example, Christian and Wilson [3] found that areas in Saskatchewan, Canada, dominated by the introduced forage grass Agropyron cristatum are sequestering less C into their soils compared to developing native prairie stands with similar land use histories