Spatiotemporal characteristics of seed rain and soil seed bank of artificial Caragana korshinskii Kom. forest in the Tengger Desert, China

Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants during the later periods of vegetation restoration remains unclear.Therefore,this study was conducted to bridge the knowledge gap by investigating the regeneration dynamics of artificial forest under natural conditions.The information of seed rain and soil seed bank was collected and quantified from an artificial Caragana korshinskii Kom.forest in the Tengger Desert,China.The germination tests were conducted in a laboratory setting.The analysis of species quantity and diversity in seed rain and soil seed bank was conducted to assess the impact of different durations of sand fixation(60,40,and 20 a)on the progress of vegetation restoration and ecological conditions in artificial C.korshinskii forest.The results showed that the top three dominant plant species in seed rain were Echinops gmelinii Turcz.,Eragrostis minor Host.,and Agropyron mongolicum Keng.,and the top three dominant plant species in soil seed bank were E.minor,Chloris virgata Sw.,and E.gmelinii.As restoration period increased,the density of seed rain and soil seed bank increased first and then decreased.While for species richness,as restoration period increased,it gradually increased in seed rain but decreased in soil seed bank.There was a positive correlation between seed rain density and soil seed bank density among all the three restoration periods.The species similarity between seed rain or soil seed bank and aboveground vegetation decreased with the extension of restoration period.The shape of the seeds,specifically those with external appendages such as spines and crown hair,clearly had an effect on their dispersal,then resulting in lower seed density in soil seed bank.In addition,precipitation was a crucial factor in promoting rapid germination,also resulting in lower seed density in soil seed bank.Our findings provide valuable insights for guiding future interventions during the later periods of artificial C.korshinskii forest,such as sowing and restoration efforts using unmanned aerial vehicles.

Diversity of soil bacteria and fungi communities in artificial forests of the sandy-hilly region of Northwest China

Soil erosion is a serious issue in the sandy-hilly region of Shanxi Province,Northwest China.There has been gradual improvement due to vegetation restoration,but soil microbial community characteristics in different vegetation plantation types have not been widely investigated.To address this,we analyzed soil bacterial and fungal community structures,diversity,and microbial and soil environmental factors in Caragana korshinskii Kom.,Populus tomentosa Carr.,Populus simonii Carr.,Salix matsudana Koidz,and Pinus tabulaeformis Carr.forests.There were no significant differences in the dominant bacterial community compositions among the five forest types.The alpha diversity of the bacteria and fungi communities showed that ACE(abundance-based coverage estimator),Chao1,and Shannon indices in C.korshinskii forest were significantly higher than those in the other four forest types(P<0.05).Soil organic matter,total nitrogen,and urease had a greater impact on bacterial community composition,while total nitrogen,β-glucosidase,and urease had a greater impact on fungal community composition.The relative abundance of beneficial and pathogenic microorganisms was similar across all forest types.Based on microbial community composition,diversity,and soil fertility,we ranked the plantations from most to least suitable as follows:C.korshinskii,S.matsudana,P.tabulaeformis,P.tomentosa,and P.simonii.

Emergy evaluation of the artificial forest ecosystems in the watershed of Miyun Reservoir:a case study for ecosystems valuation and environmental management

To build the artificial forest ecosystem is the major eco-economic development model in the watershed of Miyun Reservoir. It is very important to evaluate the benefits of those ecosystems. Emergy theories are very helpful for us to establish a science-based assessment framework. Emergy evaluation of the artificial forest ecosystems in the watershed of Miyun Reservoir is used to asses the relative values of several ecological functions (sometimes called ecosystem services) and main ecosystem storages (sometimes called natural capital). The main driving energies, internal processes and storages are evaluated. The main functions, including transpiration, GPP and infiltration, are evaluated, which are 609em$/ha/yr, 6,245em$/ha/yr and 340em$/ha/yr respectively. The total values of major environmental services are 4,683em$/ha/yr in the artificial forest ecosystem. The main storages of natural capital including live biomass, soil moisture, organic matter, underground water and landform are estimated, which are 112,028em$/ha, 9em$/ha, 40,718em$/ha, 34em$/ha and 6,400,514em$/ha respectively. The largest value is landform, which accounts for 97.7% of these calculated total emdollar values. The concept of replacement value is explored using the emergy values of both ecosystem services and natural capital. The total calculated replacement values are 302,160em$/ha.

Formation mechanisms and remediation techniques for low-efficiency artificial shelter forests on the Chinese Loess Plateau

The construction of artificial shelter forests(ASFs)has resulted in substantial ecological,economic,and societal benefits to the Chinese Loess Plateau(CLP).However,the health and benefits of ASFs are being increasingly threatened by the formation of low-efficiency artificial shelter forests(LEASFs).In this study,LEASFs are systematically analyzed in terms of their status,formation mechanisms,and developmental obstacles.The key restoration techniques and schemes were summarized to improve the quality and efficiency of LEASFs.LEASFs are formed by relatively complex mechanisms,but they arise mainly due to poor habitat conditions,improper tree species selections,mismatch between stands and habitat,extensive forest management measures,and human interferences.The restoration and improvement of LEASFs are hindered by water deficits,mismatch between stands and habitat,single management purpose,and low efficiency.LEASFs are becoming more complex due to their wide range,the challenges associated with their restoration,and insufficient technological measures for their restoration.The key techniques of the quality and efficiency improvement of LEASFs include basic forest tending methods,near-natural restoration,multifunction-oriented improvement,and systematic restoration.An understanding on the formation mechanisms of LEASFs and a scientific approach toward their restoration are urgently needed and critical for the ecological protection and high-quality development of LEASFs on the CLP.Based on these analyses,we recommend strengthening the monitoring and supervision of LEASFs,considering the bearing capacity of regional water resources,implementing multiple restoration techniques,promoting multifunction-oriented ecological development,and exploring new management concepts to achieve the sustainable development of ASFs on the CLP.

The effects of anthropogenic noise on nest predation with respect to predator species across different habitats and seasons

Noise pollution is a maj or component of sensory pollution that can disrupt the well-being and functioning of living organisms,affect a variety of life history traits in animals,and reduce their reproductive success.In this study,we used artificial nest experiments with noise manipulation to investigate the influence of anthropogenic noise on nest predation during the breeding and non-breeding seasons and in different forest habitats.We found that the noise treatment did not alter the predation rates or survival probabilities of birds in artificial nests.However,the diversity and species composition of nest predators in artificial pine forests varied between breeding and nonbreeding seasons,which may be explained by season-specific adaption of nest predators to bird nests or the unstable ecosystems of artificial forests.The diversity and species composition of nest predators differed between the different forests,probably because of differences in habitat heterogeneity.Predation time varied with treatment,season,and habitat,although most predators were nocturnal mammals.Niche segregation or changes in optimal foraging time may explain this phenomenon.

Bioactive Characteristics of Soil Microorganisms in Different-aged Orange (Citrus reticulate) Plantations

[Objective] The paper was to study the bioactive characteristics of soil microorganisms in different-aged orange plantations. [Method] Taking 010 cm deep soil in 3 orange plantations with different planting years in suburb of Yichang City as the test object, the variation rule of total organic carbon, total nitrogen, soil pH value, microbial biomass carbon, microbial biomass nitrogen, number of 3 main types of soil microbial flora, basal respiration, microbial entropy and metabolic entropy in differentaged orange plantations was studied. [Result] With the increase of planting years, the soil acidification of different-aged orange plantations was aggravating; total organic carbon and total nitrogen content increased first and then decreased; the total number of soil microorganism showed a downtrend, of which the number of bacteria decreased significantly, the number of actinomycetes had small changes, the number of fungi increased significantly, and the ratio of bacteria and fungi in soil （B/F） showed a decreasing trend. Soil microbial biomass carbon was fluctuated within a small range, whereas soil microbial biomass nitrogen decreased significantly; soil microbial entropy decreased significantly, and metabolic entropy showed an increasing trend. This indicated that the decrease of soil pH value affected the changes of soil microbial flora, microbial activity, microbial biomass carbon and nitrogen and soil major nutrients, and further affected the normal exertion of soil function. [Conclusion] The study explores soil nutrient characteristics and changes of microbial flora in test area, which will provide scientific basis for further study on orchard soil and orchard management.

Studies on Ecological Monitoring of Plant Community and Plant Diversity in Shenzhen, Southern China

From Jan. 2013 to Nov. 2018, we carried out the investigation on vegetation studies in the ecological monitoring programs, Shenzhen and totally researched 170 plant communities of mountain areas etc., few areas of street regions and parks etc., for communities’ structural characteristics and plant diversity. We comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level and the main affected factors. We also researched and analyzed these communities’ structural characteristics and pant diversity, comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level, the main affected factors;researched and analyzed the relationship between plant community structure characteristics with the absorbing ability to PM2.5 pollutants. The result showed that the structure and plant diversity of natural forest were obviously better than artificial disturbed forest or artificial forest, the semi-natural forest was the middle level of the forests, In the indices of height, DBH, coverage and crow width etc. of tree layer, natural forests and semi-natural forests were obvious higher than that of artificial disturbed forest or artificial forest;in some forests of artificial disturbed forest or artificial forest, though their richness indices of family and genus were a slightly higher, but this contribution was majorly due to herb layer plants, and some shrub layer plants. Analyzing three kinds of communities, the number of tree layer species of natural forest was the largest, and their every α-diversity index value was the highest;these characteristics values of semi-natural forest were second, artificial disturbed forests or artificial forests were the lowest;in shrub layer, and herb layer, few α-diversity indices of artificial disturbed forest or artificial forest were a slightly higher than that of some natural forests, but the integral values of the diversity indices of natural forest and semi-natural forest were obviously higher than the former. The research showed that in the artificial disturbed forest or artificial forest, because there have some little scale clearing areas, so some pioneer plant species could enter the community and formed a temporarily increase of species diversity, however, these species major were some shrub and herb plants;but tree layer possessed obviously more, even surpassed several ten times biomass than shrub and herb layers. Therefore, the respects of maintain ecosystem stability and other ecological efficient have major and dominated position and so on;and then this community can be natural recovery and succession, those forementioned new entire plants shall withdraw from the community and are replaced by the original plants of the community;but this process has already caused the ecological efficient loss and ecosystem unstable. Above research results are better evidence and theory reference to the argument problems on that are natural forest and natural restoration forest biodiversity higher? or is artificial forest biodiversity higher? and or is more artificial disturbed forest higher? Our researches showed that used random investigation method set quadrats, and combined typical investigation method, the structural indices in the all layer of community and all diversity indices of tree, shrub and herb layers and the integral values were similar, same or usually these indices in the community which set 600 m2, 800 m2 total quatrat area were higher (α-diversity) than that of more than 3000 m2, 4000 m2 or 7000 m2, even more than 17,000 m2 total quadrat area of communities. These lots of researches further proved that according to minimum area method for vegetation survey, in subtropical region, using random investigation method combined with typical investigation set 400 m2 or 400 m2 - 500 m2 total quad

Summarization on Evaluation of Ecological Value of Artificial Forest

This paper is a summarization on evaluation of value of artificial forest. The main contents include: (i) the difference in concepts between ecological function, ecological efficiency and ecological benefits of artificial forest; (ii) the motive and several taches of economic feedback or compensation for ecological benefit; (iii)the ecological efficiencies of artificial forest and the main correlative factors which includes the ecological efficiencies of artificial forest and the main correlation factors infecting the ecological efficiency; (iv) the basic math correlations between ecological efficiencies of artificial forest and the related factors; (v) service range of the ecological efficiencies of artificial forest; and (vi) the basic principle of measurement of ecological efficiencies of artificial forest. At the end, the basic methods of main ecological efficiencies of artificial forest are expatiated.

Study on Soil Moisture Distributing Characteristics of Artificial Forest in Mountainous Region

Physical characteristics of soil structure and soil moisture of five kinds of artificia! forests were researched in Shengquan Temple Forestry Farm, in the southern mountainous area of Jinan City, in order to offer scientific management and nurture of forest vegetation in mountainous area of North China. Results indicated that： （1） In these artificial forests researched, some indexes expressing soil pedonydrological physical character, such as soil density, porosity, infiltration rate, were much better than those in bare land, and these indexes Showed this order： mixed forest 〉 pure forest, Kalopanax pictus 〉 Koelreuteria paniculata 〉 Pistacia chinensis. （2） In dry and rainy seasons, with the increasing of soil depth, soil water content decreased in most parts of forest, and their extent of change was less than those in bare land. （3） With the increasing of soil depth, soil saturated water content decreased in all kinds of forests. Water storing capacity of surface soil layer was the best in the mixed forest, while differences were little in other forest. Water storing and adjusting capacity was good in the mixed forest, while water offering capacity had little discrepancy in all forests. Conclusions show that judging from water conservation and water use efficiency, mixed forest is better than pure forest, and in pure forest K. pictus is better than K. paniculata. Therefore, it is proposed that in the future, mixed forest should be fostered and managed firstly, the species being made up of K. pictus and P. chinensis. In the pure forest, K. pictus is much better than others. Nowadays K. paniculata, and P, chinensis, especially their soil surface vegetation and litter, should be protected. As to poor forest, closing hill for afforestation should be adopted. Poor forest have better be reconstructed to be mixed forest in available conditions.