Effects of season and frequency of burning on a phryganic rangeland in Greece.

Pbrygank rnngehnds dominated by Sarcopoterium spinosum, a thorny and unpalatable dwarf shrub, are a cummun vegetation type over the eastern Mediterraneancountries. In sucbarangeland of northern Greece, the effect of early spring and fall burning, applied once, twice, and three times in a 3-year period, was studied. Season of burning did nut have any significant effect on the dominant shrub. Frequency of burning, however, significantly reduced the plant yields but altered species composition only slightly and bad no effect on soil organic matter and acidity. Burning has only temporary effects on pbryganic rangelands due to the high regeneration capacity of the component species. If prescribed, tire can be used a a tool to suppress the shrub and increase the availability of herbage for the benefit of the grazing animals. Plant communities dominated by Sarcopoterium spinosum (L.) Spach. , a thorny and flammable dwarf shrub of less than 50 cm tall, are a common vegetation type in the eastern Mediterrannean countries (Litav and Orshan 1971). In Greece, such communities are known as “phrygana”and they are widespread in areas with long, dry, and hot summers and mild and rainy winters, normally found in the southern part of the country. They usualy grow on dry, rocky, and friable soils without active calcium (Debazac and Mavrommatis 1969). Phrygana are more open communities than are mediterranean maquis or chaparral and they have an important herbaceous element. Physiognomically, they can compare with the coastal sage scrub, the vegetation type which lies below chaparral and extends to the South Coast Ranges of California (Munr and Keck 1968). Phryganic communities are important grazing lands for livestock, mainly sheep, in the winter time. Sarcopoterium spinosum, however, is unpalatable to these animals, while its spines injure them. In places where it gets dense, free movement of sheep becomes impossible and considerable area of valuable grazing land is thus lost. To control this troublesome species and to, consequently, increase the grazing capacity of the phryganic rangelands, shepherds have been using fire for a long time. However, the fires set by those people are uncontrolled and usually have more harmful than desirable effects (Papanastasis 1977). If fire is to be used rationally in management of phryganic rangelands, a full knowledge of its ecological role in those ecosystems is needed. Furthermore, precise information is required on the effects of prescribed burning if it is going to be applied for improvement of these grazing areas. The effects of fire on range communities have received considerable attention and some excellent reviews are available (Biswell 1974; Daubenmire 1968; Naveh 1974; Wright 1974; Mueggler 1976). Nevertheless, information on fire ecology and management on the phryganic communities is scanty (Papanastasis 1977). The objective of this paper was to study the effects of season and frequency of burning on the phryganic rangelands for a better understanding of the ecological role of fire as well as its use for rational management of those areas for the benefit of livestock and the wild animals.