At the South Edge of the Tengger Desert, the sampled sites of mobile sanddune, semi-fixed sand-dune and fixed sanddune were selected as the different stages of the reversion process of desertification with the method of substituting time with space, and topsoil mineral elements of the decertified land were studied reversion process of desertification.

以騰格里沙漠南緣沙漠化土地為研究對(duì)象网友自拍日韩经典视频，應(yīng)用時(shí)空替代法選擇流動(dòng)沙丘日韩主播网红视频自拍网站、半固定沙丘黄片一级域名、固定沙丘的沙漠化逆轉(zhuǎn)序列樣地日韩一区二区在线视频播放，研究了沙漠化逆轉(zhuǎn)過(guò)程土壤礦質(zhì)元素的變化特征。

But shooting the sun is tricky. On a clear day, the sun is so bright that your camera's meter will tend to underexpose everything else in the frame. Shoot in manual mode, or take a reading without the sun in frame, depressing the shutter button halfway to hold the exposure, then reframe before you shoot. If you're shooting film, bracket a lot to make sure of getting the exposure you want.

把太陽(yáng)放在構(gòu)圖中以表達(dá)沙漠中的高溫和荒蕪亚洲ⅴ国产v天堂a无码二区，但拍攝太陽(yáng)比較麻煩www.色色99，晴空下的陽(yáng)光影響相機(jī)的感光計(jì)，以至于構(gòu)圖中其它部分曝光不足综合区图片区视频区亚小说区，為避免這種情況国产一级A片婬片免费，要啟用相機(jī)的手動(dòng)模式，或者是將太陽(yáng)從構(gòu)圖中排除后亚洲欧美黄色免费看，半按下快門(mén)固定曝光值亚洲免费aa视频，然后重新選擇有太陽(yáng)的構(gòu)圖，將快門(mén)按到底在线观看国产成人综合网站视频。

Think about including the sun in your photograph—it's one sure way to say hot and harsh. But shooting the sun is tricky. On a clear day, the sun is so bright that your camera's meter will tend to underexpose everything else in the frame. Shoot in manual mode, or take a reading without the sun in frame, depressing the shutter button halfway to hold the exposure, then reframe before you shoot.

把太陽(yáng)放在構(gòu)圖中以表達(dá)沙漠中的高溫和荒蕪日韩一级片网站，但拍攝太陽(yáng)比較麻煩，晴空下的陽(yáng)光影響相機(jī)的感光計(jì)www.男人插，以至于構(gòu)圖中其它部分曝光不足首页一黄色视频，為避免這種情況，要啟用相機(jī)的手動(dòng)模式黄片动图麻豆免费，或者是將太陽(yáng)從構(gòu)圖中排除后黄色18网站，半按下快門(mén)固定曝光值，然后重新選擇有太陽(yáng)的構(gòu)圖大乳美女深夜自慰，將快門(mén)按到底老女人喷水毛片。

First of all,we tested the germination and water uptake rate of 47 species typical xerophil seeds grow up in north China from 20 families,38 genuses under sufficient water and different Grads water stress by high-molecular-weight polyethylene glycol(PEG6000).The results show that Xerophil seeds from the same habitat exhibited similar patterns in response to water stress.Xerophil seeds from arid community were stronger in germination and imbibition than that from other two communities under serious water stress,whereas Xerophil seeds from humid community were sensitive to any degree of water stress.Namely,the seeds live in arid habitat possessed high germination and quickly water uptake in sufficient water or any degree of water stress,but the others grow up in humid habitat shown significant difference which germination and water uptake well under sufficient water but inhibited even if slight water stress.

首先，我們通過(guò)對(duì)20個(gè)科91福利视频，38屬午夜福利网在线观看，47種旱生植物種子在水分充足和不同梯度的干旱處理(聚乙二醇PEG6000)條件下的萌發(fā)率及吸水率實(shí)驗(yàn)發(fā)現(xiàn)，當(dāng)水分脅迫強(qiáng)烈時(shí)在线一级油黄片，分布于干旱沙漠地區(qū)的植物種子其吸水率和萌發(fā)率都高于半干旱和濕潤(rùn)地區(qū)的植物群落新国产在线精品免费AV，相反，濕潤(rùn)地區(qū)植物種子的吸水率和萌發(fā)率對(duì)任何的水分脅迫都表現(xiàn)出敏感的響應(yīng)趨勢(shì)jjzzjizz中国，也就是說(shuō)99久久性爱白浆，生境惡劣的植物種子在較強(qiáng)的干旱脅迫下，仍然保持了較高較快的萌發(fā)率及吸水率国产精品第二页，水分充足與水分缺乏時(shí)無(wú)顯著差異7777网址，而生境相對(duì)較好的植物種子在水分充足情況下萌發(fā)與吸水良好，但在干旱脅迫時(shí)則受到明顯抑制华人黄视频网站，水分充足與水分缺乏時(shí)差異顯著黄频网页免费。

The Sahara divides the continent into North and Sub-Saharan Africa . These two regions are culturally and climatically distinct. The southern border of the Sahara is marked by a band of semiarid savanna called the Sahel ; south of the Sahel lies the lusher Sudan .

撒哈拉沙漠將非洲大陸分割成兩部分，北非和南部黑非洲国产熟女AV免费观看尤物，這兩部分的氣候和文化截然不同免费簧网站永久在线播放国产，撒哈拉沙漠南部邊界是半干旱的熱帶稀樹(shù)草原偷拍网站大全，阿拉伯語(yǔ)稱為&薩赫勒&，再往南就是雨水充沛成h人视频网站，植物繁茂的南部非洲欧美潮喷十大喷潮，阿拉伯語(yǔ)稱為&蘇丹&，意思是黑非洲福利影视亚洲影视在线观看。

Our country's deserts mainly lie in arid and semiarid areas, mostly with scarce precipitation and lack of water resource, neither natural vegetation with relatively strong drought-resistance capability nor plantation, like diversifolious poplar, dryland willow, shrubby sand willow, saxoul and Hedysarum mongolicum Turcz,etc., can be protected effectively, this leads to desertification area expansion and frequent sand storm, which seriously affect people's work and life.

我國(guó)沙漠多處于干旱和半干旱地區(qū)亚洲日本亚洲国内精品自在自线，絕大部分地區(qū)降水稀少，水資源缺乏一级做一级a做片性视频无遮挡，無(wú)論是具有較強(qiáng)抗旱能力的天然植被亚洲欧美一区日韩一区a国产传媒，還是人造林如胡楊、旱柳插女人视频，灌木類沙柳色色色wang、梭梭、楊柴等都得不到有效保護(hù)欧美精品黑人白妞大战，導(dǎo)致沙化面積擴(kuò)大亚洲,日韩,性爱，沙塵暴發(fā)生頻繁，給人民群眾的生產(chǎn)生活帶來(lái)嚴(yán)重影響黄色黄片一个人www。

On the basis of investigation data collected from 20 plots of the fixed dunes and the semi-fixed dunes in Wulanbuhe desert characteristics of species diversity and spatial distribution pattern of Hedysarum scoparium population were investigated.

根據(jù)烏蘭布和沙漠固定沙丘和半固定沙丘20個(gè)樣方的調(diào)查數(shù)據(jù)欧美日韩精品一二，對(duì)不同生境中花棒群落物種多樣性及其種群空間分布格局進(jìn)行了研究。

In this study, with the psammophilous Caragana Korshinskii-Artemisia ordosica communities on semifixed dunes and fixed dunes in Shapotou region at the southeastern fringe of the Tengger Desert as the observation sample plots, the survey quadrats were arranged in the vegetation community areas with different types and coverages of soil microbiotic crusts.

本文以騰格里沙漠東南緣的沙坡頭地區(qū)半固定沙丘檸條一油蒿群落和固定沙丘檸條一油蒿群落為觀測(cè)樣地国产黄色视频高清在线观看，選擇具有不同類型生物土壤結(jié)皮分布的植被群落為觀測(cè)樣方欧美巨大XXXX做受高清。

In this study,with the psammophilous Caragana Korshinskii-Artemisia ordosica communities on semifixed dunes and fixed dunes in Shapotou region at the southeastern fringe of the Tengger Desert .

本文以騰格里沙漠東南緣的沙坡頭地區(qū)半固定沙丘檸條-油蒿群落和固定沙丘檸條-油蒿群落為觀測(cè)樣地，選擇具有不同類型生物土壤結(jié)皮分布的植被群落為觀測(cè)樣方尤物网站在线免费看。

The Hodotermitidae are a semi-desert species known as forage bants.

草白蟻科常稱為草料蟻，是一種半沙漠種国产在线xx。