Conservation of Species in Dynamic Landscapes: Divergent Fates of Silene tatarica Populations in Riparian Habitats

• Published in: Conservation biology Vol. 20; no. 3; pp. 844 - 852
• Main Authors: JÄKÄLÄNIEMI, ANNE, TUOMI, JUHA, SIIKAMÄKI, PIRKKO
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.06.2006; Blackwell Science; Blackwell; Blackwell Publishing Ltd
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Computer Simulation; Conservation; Conservation biology; Conservation of Natural Resources; Conservation, protection and management of environment and wildlife; Ecosystem; Extinct species; Fundamental and applied biological sciences. Psychology; General aspects; Habitat conservation; Habitats; Metapopulation ecology; Models, Biological; Models, Statistical; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Plant populations; Plants; Population Dynamics; Population growth; Population growth rate; Riparian ecology; Riverine habitats; Rivers; Silene - physiology; Silene tatarica; Species extinction; Stochastic Processes; Time Factors; Wildlife conservation; Landscape; Riparian; Dicotyledones; Angiospermae; Spermatophyta; Habitat; Silene; Caryophyllaceae; Environmental protection
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1111/j.1523-1739.2006.00348.x

In transient environments, where local extinctions occur as a result of destruction or deterioration of the local habitat, the long-term persistence of a species requires successful colonizations at new, suitable sites. This kind of habitat tracking should be associated with the asynchronous dynamics of local populations, and it can be especially important for the conservation of rare plant species in riparian habitats. We determined spatiotemporal variation in the demography of the perennial Silene tatarica (L.) Pers. in 15 populations (1998-2003) located in periodically disturbed riparian habitats. The habitats differed according to their morphology (flat shores, slopes) and the amount of bare ground (open, intermediate, closed) along a successional gradient. We used elasticity and life-table response analyses and stochastic simulations to study the variation in population demography. Finite population growth rate was higher in intermediate habitats than in open and closed habitats. In stochastic simulations population size increased in most cases, but four populations were projected to become extinct within 12-70 years. The viability of local populations depended most on the survival and growth of juvenile individuals and on thefecundity of large fertile individuals. On a regional scale, the persistence of this species will require a viable network of local populations as protection against local extinctions caused by natural disturbances and succession. Accordingly, the long-term persistence of riparian species may depend on habitat changes; thus, their conservation requires maintenance of natural disturbance dynamics. Along regulated rivers, management activities such as the creation of open habitats for new colonization should be implemented. Similarly, these activities can be rather general requirements for the conservation of endangered species dependent on transient habitats along successional gradients.