Читать книгу Marine Mussels - Elizabeth Gosling - Страница 38

Ecology is the study of how organisms interact with one another and with their physical environment. The distribution and abundance of organisms on Earth is shaped by both biotic (living organism‐related) and abiotic (physical) factors. Ecology is studied at many levels, including at the level of the organism, population, ecosystem and biosphere. At the organismal level, ecologists study adaptations, beneficial features arising by natural selection, that allow organisms to live in specific habitats. These adaptations can be morphological, physiological or behavioural. At the population level, the size, density and structure of populations and how they change over time are studied. An ecosystem consists of all the organisms in an area, the community and the abiotic factors that influence that community. Ecosystem ecologists often focus on flow of energy and recycling of nutrients (reviewed in Dame 2012; Riisgård 2017). Finally, the biosphere is the planet Earth, viewed as an ecological system. Ecologists working at this level study global patterns, species distribution, interactions among ecosystems and phenomena that affect the entire globe, such as climate change (OpenStax College 2013).

The environment embodies everything outside the organism that impinges on it, including physical factors (e.g. temperature, salinity and light) and biological factors (e.g. predators, competitors and parasites). An organism’s response to these factors influences its distribution and abundance on both a local and a regional scale. In this chapter, the effects of temperature and salinity – probably the two most important physical factors governing the distribution of marine organisms – will be described. Their effects on other aspects of mussel biology, such as feeding, reproduction, growth and respiration, and osmotic regulation, are covered in Chapters 4, 5, 6 and 7, respectively. Other limiting factors, such as aerial exposure, oxygen concentration, currents and substrate type, will be briefly reviewed in this chapter. In addition, effects of biological factors such as predation and competition will be considered. Pathogens and parasites (see Chapter 11) also influence the ecology of bivalve populations. Finally, the potential and observed impacts of climate change on marine ecosystems will be discussed.

Before describing the major factors that influence mussel distribution patterns, information on global and local ranges of representative marine mussel species is presented in the following section.