Life-history theory and management - Ecological Applications: Toward a Sustainable World - page 59

3 Life-history theory and management

To understand why one species is successful in a particular location while another is not, we can focus on the
sequence of events that occur in the organism's life cycle and the suite of species traits they possess. This infor-
mation can be put to good use when restoring degraded habitat or prioritizing invaders and endangered species
for special management attention.

Chapter contents
3.1 Introduction - using life-history traits to make management decisions

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3.2 Species traits as predictors for effective restoration 61

3.2.1 Restoring grassland plants - a pastoral duty 62

3.2.2 Restoring tropical forest - abandoned farmland reclaimed for nature 62

3.3 Species traits as predictors of invasion success 65

3.3.1 Species traits predict invasive conifers 66

3.3.2 Invasion success - the importance of fl exibility 66

3.3.3 Separating invasions into sequential stages - different traits for each? 68

3.3.4 What we know and don't know about invader traits 71

3.4 Species traits as predictors of extinction risk 71

3.4.1 Niche breadth and fl exibility - freshwater and forest at risk 72

3.4.2 When big isn't best - r / K theory, harvesting, grazing and pollution 73

3.4.3 When competitiveness matters - CSR theory, grazing and habitat fragmentation 77

Key concepts
In this chapter you will
recognize that species can be classifi ed according to features of their life history (e.g. annual/peren-
nial) and other ecological traits (e.g. size, growth rate)
understand that theory has been developed to link suites of traits to particular kinds of environ-
ments ( r / K selection; CSR)
realize that managers do not need to know the restoration, invasion or extinction potential of every
conceivable species - decisions may be based just on knowledge of traits
weigh up the value of databases of gardeners, ornithologists and anglers that record both success-
ful and unsuccessful introductions
appreciate that species that are endangered in one place may be undesirable aliens in another
recognize that habitat generalists are often excellent candidates for successful restoration (a good
thing) or invasion (a bad thing) whereas habitat specialists are likely to be particularly vulnerable
to extinction
understand that r -selected species fi gure prominently in restoration and invasions whereas K -
selected species are often the most vulnerable to human-caused habitat change
note the useful distinction between competitive (C), ruderal (R) and stress tolerant (S) strategies
in predicting species' behavior, particularly in the management of plants but sometimes animals
too

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