階地段丘 的英文怎麼說
中文拼音 [jiēdeduànqiū]
階地段丘
英文
bench terrace-
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縣沙坡頭地區人工固沙植被作為研究對象，採用傳統生態學的野外調查方法，從植被群落的組成、多樣性、生活型、群落生長動態、垂直結構特徵、水平結構特徵、群落結構與周圍環境（土壤含水量、溫度）相互關系及其與植物自身生理生態適應特徵關系等多個角度研究了人工植被群落的結構及其動態變化，取得了如下研究結果： 1 、植被群落組成、多樣性及生活型：沙坡頭地區人工植被經過近50年的演變，從流動沙丘到固定沙地，沙地植被的動態變化經歷了從人工植被到人工?自然植被的轉變，從人工植被建立初期的少數幾種引種植物到現有30多種植物，隨著固定沙地時間的延長，植物種類日趨豐富，並且人工植被在15 25年、 40 50年兩個階段，物種的周轉速率最大，即群落結構變化最大。The most direct embodiment is the fluctuant images of grain - size parameters brought about by the bounce of grain - size eigenvalues. in order to discuss dune sedimentary and the cause of its evolvement, in this paper we also contrast every oxygen isotope phase
為進一步探討砂丘沉積及其演變的原因，本文還將米浪溝灣地層剖面150ka以來不同時段樣品的mz和sc d的平均值與相同時期氧同位素諸階段進行了對比。Firstly, most theoretical researches and practical explorations deal with the farmland consolidation practices in northern plains and correspondingly farmland consolidation project planning and design in southern hilly region is less involved. secondly, farmland consolidation, however, has just begun in china and it mainly aims to increase agrarian areas in a majority of regions, not yet to attain the sustainable utilization of land resources based on the project analyses. behind the current " positive increase " in economic benefits, the truth is the " negative increase " in ecological, social and economic benefits in the long run
然而現階段我國在農地整理的研究上還存在一些不足之處：一是這方面的理論研究與實踐探索目前還主要集中在北方平原地區，對南方丘陵地區的農地整理規劃設計探討得比較少；二是在當前我國農地整理項目規劃設計的實踐中還普遍存在一些問題，大多數地區農地整理目標仍主要是擴大耕地數量，補償因非農建設佔用的耕地，尚未進入以項目分析為基礎，以土地資源的可持續利用為目標的階段，一些反映近期經濟效益的喜人的「正數增長」後面，往往掩蓋著長遠的生態效益、社會效益和經濟效益等方面的「負數增長」 。
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