Europe’s forests are sick and getting sicker, according to a new report released yesterday by the U.N. Economic Commission for Europe and the European Commission. The comprehensive analysis found that only 35 percent of the continent’s trees are “healthy,” about 40 percent are in a “warning stage,” and about 25 percent are “damaged,” meaning they have lost more than a quarter of their leaves. Many of the problems are attributed to air pollution, extreme droughts, and acidic soils. In other forest news, conservationists and hardwood buyers and sellers gathered in Brazil this week for a workshop on sustainable forestry, sponsored in part by the World Bank. Many delegates to the meeting said that demand for wood from environmentally friendly sources is far outstripping supply, and they emphasized the need to develop more sustainable logging operations.