Symbiotic Associations

Taking account of developments over the last decade, this 2nd edition addresses advances in the field and the emergence of fields such as cellular microbiology, immunoparasitology and cytobiology which have revealed new aspects of symbiosis.

The first edition of this book, published by University Press of New England in 1986, sold over 2500 copies, and was received as the best introductory overview of this broad field. Quite a lot has happened in the field of symbiosis in the past 10 years, especially concerning molecular mechanisms. Ahmadjian and Paracer have thoroughly updated their book, addressing advances in the field and the emergence of fields such as cellular microbiology, immunoparasitology, and endocytobiology, which have revealed new aspects of symbiosis. It is the only book to cover all aspects of symbiosis at an introductory level.

Box 9E. 1 Continued FIGURE 2. The C–S–R triangle model (Grime 1979). The strategies at the three corners are C, competiti- winning species; S, stress-tolerating s- cies; R,ruderalspecies. Particular species can engage in any mixture of these three primary strategies, and the m- ture is described by their position within the triangle. comment briefly on some other dimensions that Grime’s (1977) triangle (Fig. 2) (see also Sects. 6. 1 are not yet so well understood. and 6. 3 of Chapter 7 on growth and allocation) is a two-dimensional scheme. A C—S axis (Com- tition-winning species to Stress-tolerating spe- Leaf Economics Spectrum cies) reflects adaptation to favorable vs. unfavorable sites for plant growth, and an R- Five traits that are coordinated across species are axis (Ruderal species) reflects adaptation to leaf mass per area (LMA), leaf life-span, leaf N disturbance. concentration, and potential photosynthesis and dark respiration on a mass basis. In the five-trait Trait-Dimensions space,79%ofallvariation worldwideliesalonga single main axis (Fig. 33 of Chapter 2A on photo- A recent trend in plant strategy thinking has synthesis; Wright et al. 2004). Species with low been trait-dimensions, that is, spectra of varia- LMA tend to have short leaf life-spans, high leaf tion with respect to measurable traits. Compared nutrient concentrations, and high potential rates of mass-based photosynthesis. These species with category schemes, such as Raunkiaer’s, trait occur at the ‘‘quick-return’’ end of the leaf e- dimensions have the merit of capturing cont- nomics spectrum.

The book is a new compendium in which leading termite scientists review the advances of the last 30 years in our understanding of phylogeny, fossil records, relationships with cockroaches, social evolution, nesting, behaviour, mutualisms with archaea, protists, bacteria and fungi, nutrition, energy metabolism,population and community ecology, soil conditioning, greenhouse gas production and pest status.

Throughout the natural world, organisms have responded to predators, inadequate resources, or inclement conditions by forming ongoing mutually beneficial partnerships--or symbioses--with different species. Symbiosis is the foundation for major evolutionary events, such as the emergence of eukaryotes and plant eating among vertebrates, and is also a crucial factor in shaping many ecological communities. The Symbiotic Habit provides an accessible and authoritative introduction to symbiosis, describing how symbioses are established, function, and persist in evolutionary and ecological time. Angela Douglas explains the evolutionary origins and development of symbiosis, and illustrates the principles of symbiosis using a variety of examples of symbiotic relationships as well as nonsymbiotic ones, such as parasitic or fleeting mutualistic associations. Although the reciprocal exchange of benefit is the key feature of symbioses, the benefits are often costly to provide, causing conflict among the partners. Douglas shows how these conflicts can be managed by a single controlling organism that may selectively reward cooperative partners, control partner transmission, and employ recognition mechanisms that discriminate between beneficial and potentially harmful or ineffective partners. The Symbiotic Habit reveals the broad uniformity of symbiotic process across many different symbioses among organisms with diverse evolutionary histories, and demonstrates how symbioses can be used to manage ecosystems, enhance food production, and promote human health.