Amy C. Ganguli

Plant community diversity and composition provide little resistance to Juniperus encroachment

Widespread encroachment of the fire-intolerant species Juniperus virginiana L. into North American grasslands and savannahs where fire has largely been removed has prompted the need to identify mechanisms driving J. virginiana encroachment. We tested whether encroachment success of J. virginiana is related to plant species diversity and composi- tion across three plant communities. We predicted J. virginiana encroachment success would (i) decrease with increasing diversity, and (ii)J.virginiana encroachment success would be unrelated to species composition. We simulated encroachment by planting J. virginiana seedlings in tallgrass prairie, old-field grassland, and upland oak forest. We used J. virginiana survival and growth as an index of encroachment success and evaluated success as a function of plant community traits (i.e., species richness, species diversity, and species composition). Our results indicated that J. virginiana encroachment suc- cess increased with increasing plant richness and diversity. Moreover, growth and survival of J. virginiana seedlings was associated with plant species composition only in the old-field grassland and upland oak forest. These results suggest that greater plant species richness and diversity provide little resistance to J. virginiana encroachment, and the results suggest resource availability and other biotic or abiotic factors are determinants of J. virginiana encroachment success.

Timing is Everything: An Overview of Phenological Changes to Plants and Their Pollinators

ABSTRACT: Plant-pollinator interactions are a critical component of a healthy plant community and a healthy ecosystem. However, these interactions are at risk due to many factors, including potential phenological mismatches that may disrupt the timing of successful pollination. Environmental variables influence both when plants flower and when insects pollinate, and if those variables change, so might the timing of each species. If those changes do not track each other, plants and pollinators may not be active at the same time, potentially causing substantial problems to both groups. Yet, there is little consensus thus far about how the timing of plants and pollinators has been changing and how that might ultimately influence this important ecological interaction. Here, we review the evidence for phenological shifts in both species and find that there is evidence of change, but that it is extremely species-specific with some species advancing their activities, some delaying, and some staying about the same. We also provide some management guidelines to help promote healthy plant-pollinator relationships in light of the potential variability in phenological shifts and the other threats these species face in natural areas.

An Overview of Pollination in Rangelands: Who, Why, and How

An Overview of Pollination in Rangelands: Who, Why, and How DOI:10.2458/azu_rangelands_v33i3_harmon

The Evolving Role of Women as Rangeland Educators and Researchers in Colleges and Universities and in the Society for Range Management

On the Ground In the last 30 years, women have increased in SRM membership percentage, which appears to have paralleled the number of women hired into academic positions and women entering the discipline. Although the history of women as SRM members and rangeland educators is relatively short, the increase seems to reflect that of related disciplines. Gender demographic changes have increased diversity within the SRM and many academic institutions, enhancing what each offers. Disproportionately fewer women receiving recognition and advancing to leadership positions within SRM or higher ranks within academia may reflect opportunities for the range profession to address.

An Introduction to the Special Issue on Pollinators

Pollinators provide crucial ecosystem services to rangelands. However, pollinators are undergoing a number of challenges that threaten these services. Our intent in organizing and editing this special issue of Rangelands is to provide those working in rangeland ecosystems information about why pollination is important to rangelands, why rangelands are important to pollinators, and how these relationships are being threatened. Recently pollinators have garnered attention due to high-profi le media coverage of honeybee population declines or collapses. This, coupled with increasing awareness of native pollinator decline, has paved the way for improved management resources for pollinator conservation efforts. Furthermore, federal conservation programs and other conservation-based incentive programs aimed at private lands will likely continue to increase their emphasis on maintaining, enhancing, and restoring pollinator habitat and pollinator populations in rangeland ecosystems. This special issue on pollinators will describe the connections between pollinators and rangelands, including how rangelands enhance pollinators and the services pollinators provide as well as how pollinators benefi t the objectives of rangeland managers. We begin this discussion by presenting a brief overview of how pollination works in rangelands, focusing on how plants grow and reproduce in rangelands and why they bother with bribing animals to help them in this endeavor (Harmon et al.). Benefi ts of pollination extend well beyond plant reproduction and fi tness. In the process of providing pollination services, pollinators are responsible for a host of additional ecosystem services. The importance of pollinators from a wildlife habitat perspective is discussed by Gilgert and Vaughan, along with examples of how rangeland management for pollinators can provide a useful framework for managing wildlife biodiversity. Pollinator diversity is also important in maintaining plant community diversity. Travers et al. highlight the importance of lepidopteran pollinators (moths and butterfl ies) and discuss how pollinators are important to the maintenance of rare plant species. In efforts to bring the issues threatening rangeland pollinators and their habitat to light, Cane describes the challenges that pollinators face in the western United States with an emphasis on wild bees. Rangeland management for pollinators is more specifi cally discussed by Black et al., who provide general considerations to use when looking at common rangeland management practices such as grazing, prescribed burning, mowing, and herbicide use. Although each of these management practices can result in negative consequences for pollinators, they can also be applied in a manner that will benefi t pollinators. Pollinator services are also a large concern for specialty agricultural crops. In our fi nal paper, Chaplin-Kramer et al. illustrate the value of rangeland for supplying pollination services to production agriculture in California. Papers in this issue have been peer-reviewed. Because of space limitations, we limited the number of citations within each article. Interested readers can access supplemental literature and data authors have referenced at www.srmjournals. org. To read more about pollinators visit “Buzzing the Literature” (Solga) for recent literature.