Population patchy

Patchy population is characterized by high rates of migration between habitat patches. Because of these high rates, the dynamics within the patch may be dominated by the migration instead of the local characteristics of the population. A characteristic of patchy populations is that one organism may spend its lifetime in several patches. In contrast, in a metapopulation the organism is likely to spend all of its lifespan within one patch. 

Wiens, J.A. 1976. Population responses to patchy environments. Anna. Rev. Ecol. Syst. 7, 81-120. 

Northeast Pacific decadal oscillation, water temperature, predator distribution, large-scale population patchiness, persistent widespread contamination... 

Environmental heterogeneity and the patchy distribution of organisms in space can also be considered in evaluating the risks to populations. 

D. M. Dubois. A model of patchiness for prey-predator plankton populations. Ecol. Mod., 1 67-80, 1975a. 

Habitat and Source of Small-Scale Patchiness in Pelagic Populations, Science 1978, 201 (4353), 371-373. 

Water voles, Arvicola terrestris L., in Western Siberia inhabit wet-lands in summer. The harsh Siberian climate (cold winters) causes the young-of-the-year to move from summer wet habitats to dry sites (meadows), where they winter in underground tunnels. In spring, the voles return to wet habitats again and breed (Panteleyev, 1968). In accordance with Burkey-Stenseth s (1994) model, in which long winters and patchy distribution of resources decrease the stability of populations and cause population crashes, the breeding... 

During summer, populations of water voles are structured into small local populations (Plusnin Evsikov, 1985 Evsikov, Nazarova Potapov, 1997). The formation of local populations of water voles is determined mainly by patchiness of suitable wet habitats (e.g. bogs, basin banks, etc.). Female water voles appear to be territorial within local habitats, whereas male home ranges are more extensive and widely overlap (Panteleyev, 1968 Stoddart, 1970 Evsikov et al., 1997 Rogov et al., 1992). These observations fit the predictions of Ostfeld (1985). 

Burkey, T. V. Stenseth, N.C. 1994. Population dynamics of territorial species in seasonal and patchy environments. Oikos 69 47—53. 

Weed populations tend to be veiy patchy over the field. It is very time-consuming to map weeds manually. Currently, automated systems for weed mapping are being developed. One option for some of the major weeds such as wild oats (because weeds spread by only a few metres per year) is to assess the weeds in early suimner before harvest and to produce a map. This map can then be used for patch spraying in future years. 

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