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This chapter explores the controls over nutrient pools and fluxes across different California grassland types, beginning by discussing exotic-dominated annual grasslands, where most biogeochemical studies have occurred. Patterns in these annual grasslands are compared to those in native grasslands and oak-grassland matrices. Finally, the chapter examines the roles of organisms other than plants in influencing nutrient dynamics.

In this chapter, we explore birds as drivers of nutrient dynamics across ecosystems. For example, seabirds transport nutrients from pelagic regions to land areas. We explain why nutrient transport by birds is important and how the characteristics of birds are especially effective for nutrient transport. In the case of seabirds, birds link distant ecosystems by transporting nutrients that otherwise would remain in a certain place, in ways that few other animals can. We present case studies that show the direct and indirect ecological effects of avian nutrient transport, and describe provisioning services provided by those ecological interactions. Globally, seabirds transfer an estimated 10,000 to 100,000 tons of phosphorus from sea to land annually, making up an extremely important supporting ecosystem service, due to humans' excessive use of phosphorus. Lastly, we discuss some negative effects of bird nutrient transport on people and environments, e.g. excessive nitrogen and phosphorus can pose threats to certain habitats, underlining the importance of assessing the costs and benefits of bird-mediated nutrient dynamics in human-dominated ecosystems. We must consider the diversity of ways in which humans value habitats and ecosystem services of birds, in order to find ways to balance the various ecological functions of birds.

This chapter discusses the attributes of deciduous forest herbs that significantly contribute to ecosystem-level nutrient dynamics. It attempts to distinguish among characteristics that are unique to some or all herbaceous species. It compares nutrient content and seasonal patterns of nutrient accumulation among groups of deciduous forest herbs and with overstory species. It considers site quality (nutrient availability) as a determinant of herbaceous nutrient accumulation and discusses patterns of internal cycling (retranslocation) and decomposition of ephemeral materials. Finally, the chapter offers a fresh outlook on the influence of herbaceous populations on ecosystem-level nutrient cycling. In particular, it discusses the idea that spring ephemerals function to retard nutrient loss during spring runoff with regard to its potential use and limitations in understanding the complex nature of deciduous forest ecosystems.