发布时间:2011-09-02 10:59 浏览：43974 次 已上传80个录音
Otherwise the water runs off the surface and gets wasted.
Ted Swiecki is a plant scientist in California with the Phytosphere Research company and the Vacaville Tree Foundation.
He says people should not water established trees at the base of the trunk.
This can harm the tree.
Too much water in the soil at the base of a tree can lead to the growth of fungi.
If the area is too wet, harmful organisms have a better chance to invade the tree and cause disease.
Mr. Swiecki says this is true especially in Mediterranean and semidry climates.
Many trees in these climates have adapted to having a dry area near their base during the hottest season.