Altogether, 24% of Kerala is forested.[42]: 12 Four of the world's Ramsar Convention listed wetlands—Lake Sasthamkotta, Ashtamudi Lake, Thrissur-Ponnani Kole Wetlands, and the Vembanad-Kol wetlands—are in Kerala,[43] as well as 1455.4 km2 of the vast Nilgiri Biosphere Reserve and 1828 km2 of the Agasthyamala Biosphere Reserve.[44] Subjected to extensive clearing for cultivation in the 20th century,[45]: 6–7 much of the remaining forest cover is now protected from clearfelling.[46] Eastern Kerala's windward mountains shelter tropical moist forests and tropical dry forests, which are common in the Western Ghats.[47][48] The world's oldest teak plantation 'Conolly's Plot' is in Nilambur.[49]