in
South Carolina during winter rainforest. This humid tropical forest has warm temperatures and receives rainfall year round. Vegetation consists of a majority of broadleaf evergreen species. Deciduous trees shed their leaves usually as an adaptation to a cold or dry/wet season. Evergreen trees also lose leaves, but each tree loses its leaves gradually and not all at once. Most
tropical rainforest plants are considered to be evergreens, replacing their leaves gradually throughout the year as the leaves age and fall, whereas species growing in seasonally arid climates may be either evergreen or deciduous. Most warm
temperate climate plants are also evergreen. In cool temperate climates, fewer plants are evergreen. In such climates, there is a predominance of
conifers because few evergreen
broadleaf plants can
tolerate severe cold below about . In addition, evergreen foliage experiences significant leaf damage in these cold, dry climates. Root systems are the most vulnerable aspect of many plants. Even though roots are insulated by soil, which tends to be warmer than average air temperatures, soil temperatures that drop too low can kill the plant. The exact temperature which evergreen roots can handle depends on the species, for example,
Picea glauca (White Spruce) roots are killed at . In areas where there is a reason for being deciduous, e.g. a cold season or dry season, evergreen plants are usually an adaptation of low nutrient levels. Additionally, they usually have
hard leaves and have an excellent water economy due to scarce resources in the area in which they reside. The excellent water economy within the evergreen species is due to high abundance when compared to deciduous species, In
taiga or
boreal forests, it is too cold for the
organic matter in the soil to decay rapidly, so the nutrients in the soil are less easily available to plants, thus favoring evergreens. These conditions favor the growth of more evergreens and make it more difficult for deciduous plants to persist. In addition, the shelter provided by existing evergreen plants can make it easier for younger evergreen plants to survive cold and/or drought. == Uses ==