EPOW - Ecology Picture of the Week

Town and countryside of southern England

Explanation:  This week we are flying over southern England.  There is much to be learned about landscape ecology and nature conservation from these well-manicured and long-occupied landscapes.   

Agricultural and pasture fields of England often are bordered by hedgerows of native and exotic shrubs and small trees.  The hedgerows -- which often are the only remaining natural forest cover in an area -- serve as key hiding and nesting habitat for a wide variety of game and non-game birds and small mammals, including warblers, hedgehogs,  and other species.

Studies (such as Krebs 1971) have found that hedgerows provide suboptimal "source" habitat for some species of birds such as Great Tits (Parus major).  When birds disappear from more optimal woodland sites, their vacant territories can become filled by birds from nearby hedgerows.  

French and Commins (2001) categorized some 11 classes of hedge environments in Great Britain, and found that over two-thirds of them were dominated by hawthorns (Crataegus species) or blackthorns (Prunus spinosa).  They found that native plants occupying hedgerows were not those found in more extensive woodlands, and concluded that hedgerows do not act as "woodland corridors" for plants.  

Still, in the United Kingdom, there are conservation plans for protection of ancient and species-rich hedgerows.  One estimate is that in the 6 years between 1984 and 1990, England lost some 21% of its hedgerows to development.  Hedgerows in England and Wales are currently protected and governed under the Hedgerow Regulations of 1997.

Another study (Boutin and Jobin 1998) suggested that buffer strips at the edge of cultivated fields may sufficiently protect native plants and associated wildlife in small remnant woodlots and, to a lesser extent, along hedgerows.  Such buffer strips could also reduce the invasion of weeds into the remnant woodland areas.   

The use of hedges and hedgerows for wildlife cover is not new.  The wildlife literature addressed it as early as 1939 (Edminster 1939) but for centuries it has been used to provide for huntable game. 

Information:
     Boutin, C., and B. Jobin. 1998. Intensity of agricultural practices and effects on adjacent habitats. Ecological Applications 8(2):544-557.
     Edminster, F. C. 1939. Hedge plantings for erosion control and wildlife management. Trans. N. Amer. Wildl. Nat. Resour. Conf. 4:534-541.
     French, D. D., and R. P. Commins. 2001. Classification, composition, richness and diversity of British hedgerows. Applied Vegetation Science 4(2):213-228.
     Krebs, J. R. 1971. Territory and breeding density in the Great Tit, Parus major L. Ecology 52(1):2-22.
     Rackham, O. 1980. Ancient woodland: its history, vegetation and uses in England. Edward Arnold, London.