常見例句regenerated forest under shelterwood system 傘伐作業(yè)更新林natural regeneration under shelterwood 上方天然下種更新法For mature timber stands, the approaches of selection cutting, clear cutting and shelterwood cutting 成熟的用材林應(yīng)當(dāng)根據(jù)不同情況,分別采取擇伐、皆伐和漸伐方式shelterwood cutting 漸伐irregular shelterwood system 不規(guī)整漸伐 返回 shelterwood