reserve – n. an area of land where animals and plants are given special protection

drought – n. a long period of time during which there is very little or no rain

distribution – n. the act of giving or delivering something to people

plain(s) – n. a large area of flat land without trees

take its course – expr. to permit something to happen without trying to control it

ecosystem – n. everything that exists in a given environment

stave off – p.v. to keep someone or something away usually for a short time