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This chapter examines pollination that occurs in different kinds of ecosystems and habitats, along with the implications for plant–pollinator interactions. It begins with a discussion of pollination in deserts and semiarid systems, taking into account habitat characteristics, flora and pollinating fauna, problems with triggering and timing of flowering, problems of highly dispersed flowers, increased reproductive allocation in plants, and issues of energetics, heat overload, and water balance for desert plants and animals. The chapter proceeds by considering pollination in Mediterranean ecosystems, humid tropics, and at high latitude and high altitude. Finally, it describes pollination on islands such as the Galapagos Islands, New Zealand, Hawaii, Madagascar, and Faroe Islands.

Ecological communities consist of species that interact to varying degrees within the same geographical area, and so by definition exist within a landscape context. This chapter begins by reviewing the measures and different scales at which species diversity can be assayed, including the use of spatial partitioning to evaluate multiscale patterns of diversity. The chapter then reviews correlates of species diversity, including explanations for latitudinal and elevational diversity gradients, before considering how habitat loss and fragmentation are expected to influence species diversity. The chapter tackles the debate surrounding the relative importance of habitat amount versus fragmentation in predicting species’ responses to landscape change, and highlights the importance of studying these effects at a landscape rather than patch scale. The chapter concludes with a discussion of landscape effects on different types of species interactions, and how interactions among species in different communities can give rise to metacommunity structure and dynamics.

The complex ecological interactions that structure natural communities are shaped by organismic effects on external environments (habitat construction) and by individual phenotypic adjustments (eco-devo responses). This chapter examines the community-level consequences of organismic impacts on shared resources and conditions, and of plastic trait expression. An initial section introduces the context dependence of ecological interactions. The next section explains how both habitat construction and eco-devo responses contribute to the community properties of functional diversity and complementarity. Examples illustrate the roles of species-specific environmental effects, ecological facilitation, and trait-mediated interactions such as plastic (facultative) character displacement. The chapter goes on to discuss the community consequences of habitat construction through two detailed case studies, reef-building corals and native plants, noting the impacts of coral bleaching and plant invasions. A second pair of case studies examines the community consequences of trait plasticity, focusing on plastic aspects of plant–pollinator mutualisms and on induced plant defenses.

As noted earlier and as anticipated by Charles and Francis Darwin it has been argued that plants sense the direction of gravity (gravitropism) by movement of starch granules found in cells called statocytes that contain compartments (organelles) called statoliths. The synthesis of statoliths appears to occur in the plastid (plant organelle) compartments called amyloplasts (Figure 7.1, 1). It has been suggested that this gravitropic signal then leads to movement of plant hormones such as indole-3-acetic acid (auxin) (Figure 7.2), through the phloem opposite to the pull of gravity to promote stem growth. Chloroplasts (Figure 7.1, 2) are cell compartments (plastids or organelles) in which photosynthesis is carried out. The process of photosynthesis, discussed more fully later, is accompanied by the production of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phosphate (Pi) (Figure 7.3). ATP is consumed and converted to ADP and Pi in living systems. The cycle of production and consumption allows ATP to serve as an “energy currency” to pay for the reactions in living systems. Beyond this generally recognized critical function of chloroplasts, it has recently been pointed out that light/dark conditions affect alternative splicing of genes which may be necessary for proper plant responses to varying light conditions. The organelles or plastids which contain the pigments for photosynthesis and the amyloplasts that store starch are only two of many kinds of plastids. Other plastids, leucoplasts for example, hold the enzymes for the synthesis of terpenes, and elaioplasts store fatty acids. Apparently, all plastids are derived from proplastids which are present in the pluripotent apical and root meristem cells. The cell wall (Figure 7.1, 3) is the tough, rigid layer that surrounds cells. It is located on the outside of the flexible cell membrane, thus adding fixed structure. A representation of a portion of the cell wall (as made up of cellulose and peptide cross-linking) is shown below in Figure 7.7. The cells will have different sizes as a function of where they are found (e.g., leaf, stalk, root), but in every case, the cell wall limits the size of the membrane that lies within.