Little attention has been paid to the process of mineralization of saline-alkali soils. Effects of litter addition and no addition on organic carbon mineralization in saline-alkali soil under different salinity and pH conditions under simulated natural state. The results showed that litter addition significantly (P<0.05) increased the cumulative mineralization of the 3 plots. Under the same salinity and pH conditions (except pH 10.5), the Alashan (ALS) plot has the highest cumulative mineralization among the 3 plots; under different conditions, there is no significant effect on the mineralization of the ALS plot; the Wulanchabu (WLCB) plot The mineralization amount was the highest at S9 and pH10.5, which were 2.23 gkg(-1) and 1.84 gkg(-1), respectively; the mineralization amount of the Eerduosi (ERDOS) plot decreased significantly with the gradient (P<0.05). The cumulative mineralization process fits the first-order kinetic model. Therefore, changes in salinity and pH conditions are not the most important factors affecting the cumulative mineralization of the 3 plots, but the physical and chemical properties of the soil itself and the chemical composition of litter have a closer influence on it.

In recent years,found that the general growth of Pinus tabulaeformis in Baotou urban weakness,needle appears red phenomenon.In order to analyze the growth status and the distribution of Pinus tabulaeformis in Baotou as a whole,the main reason of the recession and the growth of Pinus tabulaeformis rejuvenation techniques provide some theoretical guidance for determining the cause.Based on the growth of Pinus tabulaeformis in Baotou,the paper analyzed and compared the difference of soil moisture content and bulk density between the normal Pinus tabulaeformis and the coniferous red pine in Baotou,the results show that the red pine needles of Pinus tabulaeformis and normal soil moisture content is low,fluctuating between 4.85 ～ 9.4％,the soil water content of coniferous red pine forest was higher than that of normal Pinus tabulaeformis forest,but has not reached a significant level;Kundulun cemetery mean soil bulk density greater than 1.4g/cm3,the average soil bulk density of Arden and Jianshe Road botanical garden in 1.2 ～ 1.4 g/cm3,the soil bulk density of normal Pinus tabulaeformis was higher than that of red soil,the low soil bulk density had a certain effect on the red needles of Pinus tabulaeformis,but the effect was not significant.

Experiments were conducted by ltter bag technique on effect of simulated acid rain on decomposition rate and content of dissolved organic carbon(DOC)from leaf letter of Betula platyphylla, Ledum palustre and Rhododendron dauricum treated with pH 3.5, 5.0 and 7.0 in Genhe, Inner Mongolia Autonomous Region. The results showed that leaf litter mass of 3 species reduced the less under treatment of pH 3.5, and then under pH 5.0 and pH 7.0.The mass loss rate of three species litter leaf was ordered by L.palustre>B.platyphylla>R.dauricum. The experiment resulted that leaf litter decomposition rate and mass loss rate had a significant negative correlation with the content of C, lignin, C/N, lignin/N, but had remarkable positive correlation with the content of N, P and cellulose. Decomposition and release of DOC from different litters had the same tendency, increased first and then decreased, and then decreased slowly.

以包头市阿尔丁植物因、锦林公园、迎宾道3个样地的针叶"红化"油松与健康油松为试材,采用室外光合速率对比方法,研究了正常生长油松与针叶"红化"油松对针叶光合作用的影响.结果表明:油松的光合速率规律均呈双峰型;同一地点不同生长状况油松的光合速率有明显差异,正常油松光合速率最高峰为CO2 13.80μmol·m-2·s-1,针叶"红化"油松的最高峰值为CO2 11.60μmol·m-2·s-1;不同样地相同生长状况油松光合速率也有一定联系;同一油松一年中不同月份光合速率随光照强度的不同其变化规律呈单峰型.

近年发现,包头市区油松普遍长势衰弱,针叶出现"红化"现象.为了从整体上分析包头油松生长现状及分布规律,为确定造成油松生长衰退的主要原因及其复壮技术提供一定的理论指导.通过对包头市油松分布进行实地调查,结果表明,包头市区绿地油松与行道油松主要分布在青山区,分别占包头市区总的油松数量的61.06％和38.94％;其中东河区行道油松分布最少,占总的道路绿化油松的8.37％;九原区占总的行道油松的22.33％;青山区道路绿化油松占总行道油松的38.09％;昆区行道油松占总的行道树的31.21％.包头市区油松病虫害非常严重,主要病害表现为针叶"红化",发病率高达90.03％.

As the main tree species,Pinus tabulaeformis Carr plays an important role in greening the environment in the Baotou region.In recent years,the growth of Pinus tabulaeformis Carr in Baotou was generally weak and unhealthy,and many needles became into a red-brown.In order to identify the reasons of the unhealth of the plant,we took a field survey of Pinus tabulaeformis Carr and sampling in Baotou City,and analyzed the status of Pinus tabulaeformis Carr pest growing,and the relationship with the growth of Pinus tabulaeformis Carr.The results show that a very serious disease of the pine was red needles,the incidence rate was of 90.03%,disease index was 62.06%.Major pest was Cinara pinea Mordwilko,the incidence rate was 90.03%,disease index was 44.61%.With the growth of Pinus tabulaeformis Carr became weak,disease incidence and disease index of red needle disease were getting higher,but the disease incidence and disease index of Cinara pinea Mordwilko were getting lower.

In recent years,a phenomenon was appeared that the whole needles of Pinus tabulaeformis Carr.turned red from the top to the bottom in a large area of Baotou city.To figure out the relationship between this symptom and the nutrient content of the needles,the content of elements including N,P,K,Ca,Mg,Fe,Mn,Cu,Zn from different reddening extent needles and normal needles was analyzed.The results showed that there was significant difference in the content of N,Ca,and Cu between the serious reddening needles and normal needles.The content of P,Mg,and Fe was not significant different.There was a close relationship between the phenomenon of reddening needles and the lack of N element or the presence of excessive Ca element.The relationship between the phenomenon of reddening and the content of elements K,Fe and Zn was more complicated.

To figure out the relationship between this symptom on reddening needles of the Pinus tabulaeformis and the properties of the soil,Kun Dulun cemetery,Jianshe Road,A Erding Botanical garden in Baotou as test areas,and the Bulk density,pH,organic matter,available N,available P and available K both normal and the red needles were tested.The results showed that there was a significant difference in pH and available K between the normal and red leaves;Besides,higher pH and lower available P affect the leaves turning red directly instead of Bulk density and organic matter.

Through the studies on jujube tree burliness rate in north China,the studies showed that by adopting several kinds of annular peeling and spraying different kinds of plant incretion jujube burliness rate can be increased.Especially the burliness rate is the highest if annular peel on trunk and in florescence,if it does not peel or peel before florescence burliness rate is lower.Spraying gibberellin and plant growth hormone burliness rate is more than 50%,while CK's burliness rate is only 11.46%.

According to the ecological environment and economic situation of Zhuozi Country,through the five years' development of conversing farmland to forest(grass) land of the area,the ecological effects,economic effects and social effects of conversing farmland to forest(grass) land for the area were studied,some proposals were suggested.

Combining with background and developmental general situation for establishing the program for returning cropland to forestry (grass), taking the national general and specific policies as standpoint, economic, ecological and social benefits for returning cropland to forestry (grass) have been evaluated and analyzed in Inner Mongolia. And several suggestions have been put forward.