Study On Spectral Characters-Chlorophyll Inversion Model of Sabina Vulgaris in Mu Us Sandy Land

Sabina vulgaris is a group tree species in Mu Us Sandy Land. Understanding the growth status of Sabina vulgaris has guiding value for vegetation change monitoring. Chlorophyll is an important indicator to characterize the growth status of plants, and its content changes are important for analyzing the physiological growth status of plants and guiding the precise planting of plants. In this paper, the spectral reflectance and chlorophyll content of Sabina vulgaris were measured by SVC HR-1024 portable ground feature spectrometer and SPAD502 chlorophyll instrument, and the relationship between ground feature spectral characteristics and chlorophyll content of Sabina vulgaris was studied. The results show that there is a correlation between the vegetation index and chlorophyll, the effect of NDVI is the best, the bands with the highest correlation are the combined bands of 470nm-500nm, 610nm-680nm, and 740nm-840nm, and the wavelengths with the highest correlation are (660,790); Vegetation index, red-edge parameters, and chlorophyll have a certain correlation. The fitting effect of the model established by vegetation index is better than that established by red-edge parameters, and the highest R2 is 0.97; Among the three modeling methods, the model fitting effect of partial least squares is the best, R2 is > 0.91, and the disadvantage is that the processing process is complex; The processing method of the univariate linear regression model is the simplest, but the disadvantage is that the accuracy of the model is unstable, R2 is between 0.1-0.9, so the multivariate linear regression model is the most suitable of the three methods(R2>0.8).

Selection and Evaluation of Suitable Tree Species in Drought and High-dust Coal Base in Northwest China

To select drought-resistant and dust-tolerant tree species suitable for being planted in a drought-ridden and high-dust coal base in northwest China, we used nine tree species to determine the growth status, biomass, harm index, and photosynthetic characteristics under drought and highly dusty stress conditions. The results showed that in the drought resistance index system, their cumulative contribution rate reached 98.1%, and the drought resistance order was Ammopiptanthus mongolicus > Hedysarum scoparium > Sabina vulgaris >Caragana korshinskii > Ulmus pumila > Amorpha fruticosa > Caryopteris mongholica > Tamarix chinensis > Elaeagnus angustifolia. In the dust resistance index system, the cumulative contribution rate reached 95.2%. The dust resistance order was Caragana korshinskii > Amorpha fruticosa > Sabina vulgaris > Hedysarum scoparium > Tamarix chinensis > Ammopiptanthus mongolicus > Ulmus pumila > Caryopteris mongholica > Elaeagnus angustifolia. In the drought and dust resistance comprehensive index system, 14 indices (shoot length, stomatal conductance, and POD) had larger weights and the cumulative contribution of comprehensive indices reached 100%. The drought and dust resistance order of the test tree species was Caragana korshinskii > Ulmus pumila > Amorpha fruticosa > Sabina vulgaris > Caryopteris mongholica > Ammopiptanthus mongolicus > Hedysarum scoparium > Tamarix chinensis > Elaeagnus angustifolia. These results provided a reference for the selection of suitable greening tree species in accordance with local conditions in drought-mining areas.

Benefit Evaluation of Soil-Reinforcement by Roots between Five Plants by Analytic Hierarchy Process

Caragana microphyllaLam,Salix psammophilaC.wang et Ch.Y.Yang,Sabina vulgarisAnt,Artemisia sphaerocephalaKrasch andHippophae rhamnidesLinn are common plants used in soil and water conservation in the arid and semi-arid regions of Inner Mongolia. In order to screen the soil-reinforcement and anti-erosion plants for this area, the tensile mechanical property, root-soil surface friction property, and the root-soil composite shear property of roots were studied. During the summer drought period, ten factors of the five kinds of four-age plants were evaluated by analytic hierarchy process (AHP). The results showed that the benefit index of soil-reinforcement by roots wereCaragana microphylla(0.72)>Sabina vulgaris(0.38)>Salix psammophila(0.03)>Artemisia sphaerocephala(-0.23)>Hippophae rhamnides(-0.90). Therefore,Caragana microphyllaLam should be considered as the preferred reference specie in soil-reinforcement and anti-erosion for the arid and semi-arid regions of China.