. There are two seasons in the Comoros: the hot and humid season flowing in from the north-west from November to April and the dry season from May to October. The climate on Mayotte is, nevertheless, noticeably warmer and drier. The climate is also characterized by important local variations in temperature and precipitation according to altitude, relief and the degree of exposure to the elements. Annual precipitation therefore varies in the region of and the absolute minimum of is reached on the summit of Karthala. The hot, dry season is caused by a vast low pressure area which extends over a large part of the Indian Ocean and Central Africa. This low pressure favours gusty winds and cyclones. The last cyclone was Cyclone Gafilo, which passed close to the Comoros on 5 March 2004 causing great material damage. During the hot and humid season it can rain as much as in twenty-four hours. The dry season is calmer. The low pressure moves towards the continent of Asia (this is the monsoon, the wind blowing from the south-east) and an anticyclone forms below the Comoros. This still does not prevent the islands from having a few gusts of wind, but their intensity is a lot less than during the hot season. The two winds that bring the two different seasons are called the Kashkasi (in November) and the Kusi. Terrestrial ecology Partly as a result of international pressure during the 1990s, the government of the Union has begun to take greater care of the environment. Measures have been taken not only to preserve the rare fauna, but also to check the destruction of the environment, especially on Anjouan, which is densely populated. More precisely, in order to minimize the felling of trees for fuel, kerosene has been subsidized, and efforts are underway to replace the lost forest cover caused by the distillation of Ylang-ylang for perfume. The Fund for the Support of Community Development, sponsored by the International Development Association (IDA, a subsidiary of the World Bank) and the Comorian government, is applying itself to improving the water supply on the islands. Flora Like most islands, the diversity of the local flora suffers from two pressures, on the one hand the reduction of available space caused by humans settling in what used to be the wildest areas, and the invasion of exotic plant species such as guava trees. Much of the