So studying the processes and mechanisms of soil hydrology of microbiotic crusts as well as analyzing its influence on soil water conditions in fixed dunes will play an important role theoretically and practically in understanding the evolution of artificial vegetation community in fixed dunes and the security of artificial sand-fixing vegetation system.

因此，通過野外試驗揭示微生物結(jié)皮對土壤水文過程的影響和機(jī)理五月天色婷婷综合，評估其對雨養(yǎng)植被固沙區(qū)土壤水環(huán)境的影響狂插网，對于認(rèn)識固沙區(qū)人工植被群落的演替和人工植被固沙體系的安全性都有著重要的理論意義和實(shí)踐意義。

Using the survey data of several indexes as well as field experimental data of soil hydrology of microbiotic crusts in artificial vegetation-fixed sand dunes in Shapotou area, the impacts of microbiotic crusts on soil hydrological processes which included the penetration, interception and evaporation processes of precipitation were examined, and their mechanisms were also studied. The security problem of vegetation-fixing system due to the changed soil water environment in fixed sand dune area was analyzed further.

本文在上面的立意下a片网站免费在线观看，我們對沙坡頭人工植被固沙區(qū)對微生物結(jié)皮的若干指標(biāo)進(jìn)行了詳細(xì)的調(diào)查和試驗A∨精品男人的天堂，并安排了一系列微生物結(jié)皮土壤水文過程試驗，從不同的角度揭示了微生物結(jié)皮在降雨滲透日韩一区二区电影网站视频、攔截和蒸發(fā)過程中的作用四五月婷婷色播播，及其對降水在沙丘土壤剖面中的水分分配過程和格局的影響，并進(jìn)一步分析了微生物結(jié)皮對固沙區(qū)土壤水環(huán)境的影響和植被固沙體系的安全問題青青青手机视频免费观看。

The south sites locate on subtropical monsoonal climate region, which vegetation types mostly are evergreen vegetations and the start and end of growing season are not obvious. Therefore, BGP and EGP estimated by the model are not the real start and end of growing season, but reflect vegetation's response to regional climate changes.

這是因為南方站點(diǎn)地處亞熱帶季風(fēng)氣候區(qū)电影日本公妇在线观看，地表以常綠植被為主亚洲av自拍，植被生長季開始與結(jié)束日期均不明顯亚洲一级二级三级在线观看，因此遙感監(jiān)測的并非真正意義上的植被生長期始末日期在线三区四区，而是植被對區(qū)域氣候因子變化的響應(yīng)狀況欧美一级片专区。

For biogenic VOC modeling, emission factors, vegetation biomass and leaf area index were determined for 37 vegetation types. The widely accepted algorithm of Guenther et al.(1993), describing the relationship between light, temperature and the VOC emissions, was adopted. A new canopy model was established to simulate photosynthetically active radiation and leaf temperature within the canopy.

對于VOC生態(tài)源模式国产强奸av片，確定了37種植被的VOC排放因子裸体美女黄十八禁免费网站、生物量和葉面積指數(shù)官网免费A片；采用了相對成熟的關(guān)于VOC排放強(qiáng)度和光合有效輻射欧美自拍偷拍精品、葉面溫度的依賴關(guān)系国产青榴视频A片在线观看不卡成；建立了一個新的植被冠層模式以模擬冠層內(nèi)PAR和葉面溫度的變化。

The Journal of Vegetation Science publishes papers on all aspects of vegetation science, with particular emphasis on with that papers including theory, methodology, spatial patterns (including plant geography and landscape ecology), temporal changes (including palaeoecology and demography), processes, and description of ecological communities (by phytosociological or other methods), provided the focus is on increasing our understanding of plant communities.

植被科學(xué)雜志》發(fā)表有關(guān)植被科學(xué)方面的論文日本系列JULIA在线播放，著重于理論国产精品黄色女人视频、方法論、植物地理學(xué)和景觀生態(tài)學(xué)研究的空間模式99色免费，古生態(tài)學(xué)和人口統(tǒng)計學(xué)中的時空變化700万AV毛片导航，生態(tài)生理學(xué)中的過程和植物社會學(xué)中的生態(tài)群落描述等方面內(nèi)容，目的在于提高人們對植物群落知識的認(rèn)識和了解日韩淫乱毛片。

The aim of this research is to understand the ecological relationship between sand vegetation and environment, adaption charactristics of psammophilous plants to sandy environment and feature of plant resources in Otindag Sand Land, and further to provide theory evidence for selection optimal sand-fixation species and planning feasible process of vegetation restoration in desertification control.

本論文的目的是了解沙地植被與環(huán)境的生態(tài)關(guān)系www.13色哟哟、沙生植物適應(yīng)沙地環(huán)境的特點(diǎn)以及沙地植物資源特征，為在沙漠化防治中選擇合適的治沙物種免费无码一级A片特大黄、制定合理的植被恢復(fù)方案提供理論依據(jù)www.午夜。

Sabaigrass planting improves the soil water conservation functions. The study results indicated: vegetation influenced the soil water conservationfunctions of the purple sloping fields greatly. Pure and mixed stands of Sabaigrassvegetation not only improved the soil water conservation functions in purple soilsloping fields, but also has the better effect than wild vegetation.

2龍須草種植可明顯改良土壤蓄水性能本研究結(jié)果表明：植被的存在與否對紫色土荒山坡地土壤蓄水性能影響很大，龍須草純種植被和龍須草-林木復(fù)合種植植被不僅極顯著地改良了紫色土荒山坡地土壤蓄水性能，而且其改良效果顯著好于野生自然植被免费一级a一片一久久。

SPSS cluster analysis and CANOCO ordination method were applied to discuss the relationship between vegetation and its environmental factors in the west slope of Helan Mountain. The results show that the vegetation community can be divided into three types, namely Salsola passerina-Reaumuria soongorica community, Stipa breviflora-Stipa grandis community and Prunus mongolica-Ulmus glaucescens community.

通過SPSS聚類分析和CANOCO排序研究了賀蘭山西坡植被分布與環(huán)境因子的關(guān)系自拍视频国产1999，結(jié)果表明：在海拔梯度上，賀蘭山西坡植被大致可以劃分珍珠豬毛菜－紅砂群落小蝌蚪国产、短花針茅－大針茅群落和蒙古扁桃－灰榆群落3種類型思思99热。

From nature factor, there is arid and strong wind and plenty of sand material that derives from alleviation of rivers in Shiquanhe basin. The vegetation ecology system is very vulnerable. From human being action, the actions of secular excessive firewood and herd and disorder exploitation sandrock make origin vegetation completely destroy and alleviation including plenty of sand material whose structure is loose expose under the effect of wind force.

從自然因素看，獅泉河盆地氣候干旱多風(fēng)亚洲美女日逼A片，河流沖積形成的沙源物質(zhì)豐富高潮黄网站色在线观看免费，植物生態(tài)系統(tǒng)脆弱；從人類活動來看2020亚洲一级兔费A片，多年的濫樵欧美在线播放中文字幕、過牧、亂采砂石等行為免费无码高清黄色网址，將原植被破壞殆盡久久国产香蕉毛片一级，使結(jié)構(gòu)松散的含有豐富沙物質(zhì)的獅泉河沖積物直接暴露于風(fēng)力作用之下。

This paper presents the high-resolution sequence of vegetation change of the last inter-glacial period in Xishan Mountain,Beijing by pollen analysis and thermoluminescent dating technology with reconstruction of the palaeo-vegetation and palaeo-environment of this region.

末次冰期—間冰期氣候旋回研究是過去的全球變化研究的三大重點(diǎn)之一国产一区在线免费观看，通過孢粉分析和熱釋光斷代建立了北京西山末次間冰期植被的演化序列www.sanjipian.vom，研究了該地區(qū)古植被與古環(huán)境的演化規(guī)律。