Agricultural land comprises 54% of Lithuania's territory (roughly 70% of that is arable land and 30% meadows and pastures), approximately 400,000 ha of agricultural land is not farmed, and acts as an ecological niche for weeds and invasive plant species. Habitat deterioration is occurring in regions with very productive and expensive lands as crop areas are expanded. Currently, 18.9% of all plant species, including 1.87% of all known fungi species and 31% of all known species of lichens, are listed in the Lithuanian Red Data Book. The list also contains 8% of all fish species.