例句與用法

1. The structures and dynamic changes of the artifical sand - fixing vegetation were studied based on the follow views : components of vegetation community , plant diversity , life - forms of vegetation , trends of plant growth , characteristics of the vertical and horizontal structure of vegetation , relationship between the vegetation community and environment ( including soil moisture temperature etc . ) , relationship between the vegetation community and characteristics of plant physiological activities . some results were showed as follow : 1 . components , diversity and life style of artificial vegetation in shapotou region the marked changes of artificial vegetation have taken place during more than 40 years , since the establishment of sand - fixing vegetation
   本文以騰格里沙漠東南緣寧夏中衛(wèi)縣沙坡頭地區(qū)人工固沙植被作為研究對(duì)象，采用傳統(tǒng)生態(tài)學(xué)的野外調(diào)查方法，從植被群落的組成、多樣性、生活型、群落生長(zhǎng)動(dòng)態(tài)、垂直結(jié)構(gòu)特征、水平結(jié)構(gòu)特征、群落結(jié)構(gòu)與周圍環(huán)境(土壤含水量、溫度)相互關(guān)系及其與植物自身生理生態(tài)適應(yīng)特征關(guān)系等多個(gè)角度研究了人工植被群落的結(jié)構(gòu)及其動(dòng)態(tài)變化，取得了如下研究結(jié)果： 1 、植被群落組成、多樣性及生活型：沙坡頭地區(qū)人工植被經(jīng)過(guò)近50年的演變，從流動(dòng)沙丘到固定沙地，沙地植被的動(dòng)態(tài)變化經(jīng)歷了從人工植被到人工?自然植被的轉(zhuǎn)變，從人工植被建立初期的少數(shù)幾種引種植物到現(xiàn)有30多種植物，隨著固定沙地時(shí)間的延長(zhǎng)，植物種類日趨豐富，并且人工植被在15 25年、 40 50年兩個(gè)階段，物種的周轉(zhuǎn)速率最大，即群落結(jié)構(gòu)變化最大。