2023 Vol. 44, No. 1
The vulnerability of social ecosystem is an important content and research hotspot of sustainable development. Based on the relevant concepts and theoretical foundations, the research progress of vulnerability at home and abroad was introduced to present the overall history and status quo in this field. Finally, the research progress and hotspots of social ecosystem vulnerability were analyzed by using CiteSpace software through the core collection database of Web of Science and CNKI database. The results showed that: ① In general, the overall research situation in this field was in good condition, with developed countries contributing a lot in the number of published papers, the United States ranking first, and China ranking sixth but with a lower contribution. ② The research hotspots at home and abroad tended to be the same, but in terms of content, foreign countries tended to conduct in-depth research and improvement of theories, definitions, etc., while domestic focused on regional empirical research by using existing frameworks and methods. ③ In the research on the vulnerability of social-ecological systems, foreign countries still focused on “ecosystem” research, while domestic focused on “social system” research.
Seasonal freeze-thaw is a process that mainly occurs in high latitudes and high altitudes, causing the internal heat and moisture of the soil to fluctuate dynamically with time. Seasonal freezing and thawing changes the physical structure of the soil and reduces the stability of soil aggregates through repeated freezing and thawing; through the leaching and nitrification of the soil, it promotes the release of dissolved organic acids and changes the organic matter in the soil. The content of soil leads to the increase and decrease of soil pH values and the changes of carbon, nitrogen, phosphorus and heavy metal content; the influence of temperature and moisture makes the number and structure of microorganisms in the soil tend to be a dynamic process. Based on the review of the effects of seasonal freezing and thawing on the physical, chemical and biological properties of the soil, it is proposed to strengthen the study of frozen soil in the permafrost regions of the Qinghai-Tibet Plateau, especially the alpine forest line in southeastern Tibet, as well as field monitoring and in-situ research. As well as the study of freeze-thaw soils in a larger-scale soil niche, this is of great significance for the practice of the "two mountains" theory and the construction of ecological security barriers.
Based on the bibliometrics method, the literature related to "Bletilla" in the database of CNKI from 1990 to 2021 was made a statistical analysis, and the visual analysis was made. The research results showed that there were few research results before 2008, and after that the scholars begun to pay attention to this field. During the period of rapid growth from 2008 to 2019, the number of articles reached 99 in 2019. Since 2020, the heat started to decline, which was positively related to the market price of Bletilla striata, reflecting the change of the heat of Bletilla striata industry. The hot research field was the comprehensive field of traditional Chinese medicine and agriculture, which mainly focused on the application industry. The number of basic research was small and relatively weak, and the research focus was on the application of Bletilla striata polysaccharide, ecological planting, component content and biomaterial application. The multi-purpose of Bletilla striata provided a broad prospect for the development and utilization of Bletilla, and the protection and development of excellent germplasm resources was the premise for the healthy development of Bletilla industry.
The plant health is closely related to phyllosphere fungi, and their community structure and diversity are determined by the mutual activities of plant itself, the microorganisms and other environmental factors. In order to understand the differences of the community structure and diversity of the phyllosphere fungi which comes from different plants in the same habitat, and to determine the influences of different plants on the composition of phyllosphere fungi. The next generation sequencing method were applied to investigate the phyllosphere fungi community structures from three garden plants, including Ficus altissima, Magnolia grandiflora, Eriobotyra japonica, which were located within 50 meters in distance and around the campus of Dali University. The results showed that the alpha diversity of phyllosphere fungi was ranked as M. grandiflora > E. japonica > F. altissima. For the OTU abundance, the genus Cladosporium from phylum Ascomycota was the dominant taxon in all of the three plant phyllosphere fungi communities but the relative abundance was different. In addition, fungus communities from different plants had various endemic taxa, and the assemblies were distinct. The community structures and diversity of plant phyllosphere fungi were determined by the plant species, and the characteristics of different plants could shape their unique phyllosphere fungus communities.
According to the investigation of the damage range and the increase rate of Cuscuta japonica, the occasional, common and main host garden plants were identified, the incidence rate and damage degree of main host plants were determined, and the adaptive growth relationship between C. japonica and the main host plants was analyzed. The results showed that: (1) The damage range of C. japonica was constantly expanding, and the infection rate of trees, shrubs and ground cover were significant different, but they all increased year by year (P<0.05). (2) There were 41 species of plants belonging to 35 genera and 28 families invaded by C. japonica, among which 12 were occasional hosts, 19 were common hosts and 10 were main hosts (3 trees, 2 herbs and 5 shrubs). (3) The incidence rate and injury degree of main hosts were significantly different among species and years (P<0.05), and the symptoms and associated diseases of different hosts were significantly different. (4) The effects of C. japonica on the growth of leaves and young stems and the number of new branches of the host plants were significantly different. Host plants had significant effects on the growth and reproduction of C. japonica, and there was a significant adaptive growth relationship between C. japonica and host plants.
Abstracts In this study, vegetation of three slope aspects (semi-shady slope EN 40°, sunny slope WS33°, shady slope WN 29 °) built for five years in hilly area of Northeast Sichuan were used as the research object, and the effects of slope aspects on comprehensive vegetation management of bare slope by slope protection vegetation were studied by measuring community characteristics, landscape quality and soil properties. The results showed that: (1) Slope direction affected the community density, dominant species height and basal coverage of vegetation (P<0.05), and also affected species density, diversity, richness and evenness (P<0.05).The community density, base coverage, species diversity and evenness of semi-shady slope were higher than those of sunny slope and shady slope. (2) Slope aspect affected the landscape quality and vegetation appearance (P<0.05), and the landscape goodness of shady slopes was medium, while that of semi-shady slopes and sunny slopes was poor. (3) Slope aspect affected soil grain size composition, physical properties and chemical properties (P<0.05). The soil texture of shady slope was higher than semi-shady slope and sunny slope (P<0.05), and the soil layer thickness of sunny slope was thicker than that of shady slope and semi-shady slope. (4) In the fifth year, the soil properties, species diversity, community height and basal coverage of three slopes were higher than those in the first year (P<0.05). In conclusion, the slope aspect affected the characteristics of vegetation community, landscape performance and soil properties. As the pioneer vegetation of bare slope management, the introduced turfgrasses completely disappeared in the fifth year, but it still played an important role in local grass species colonization, bare slope vegetation reconstruction, landscape restoration and soil and water conservation.
To clarify the effects of exponential fertilization on the growth and biomass of hybrid Salix matsudana × alba seedlings can provide a basis for the seedlings cultivation. Taking the cutting seedlings of one-year-old hybrid S. matsudana × alba as the research object, the pot experiment method was adopted, and six treatments including control (CK), conventional fertilization (CF) and exponential fertilization (EF1, EF2, EF3, EF4) were set up. Each fertilization interval was 30 days and fertilization was applied five times in total. The seedling height and ground diameter of the seedlings were measured every 30 days. After the growth, the biomass was measured. The results showed that under different fertilization treatments, the seedling height and ground diameter growth of S. matsudana × alba were quite different, and the seedling height growth of EF2 treatment was the largest, which was 36.40% higher than that of CF treatment. The ground diameter growth of EF1 treatment was the largest, which was 21.63% higher than that of CF treatment. The biomass of EF treatment was significantly higher than that of CF and CK, and EF2 treatment was the best. Compared with CK treatment, the biomass of whole plant, aboveground part and belowground part increased by 96.86%, 84.31% and 157.60%, respectively. In conclusion, the exponential fertilization with nitrogen application rate of 3.0 g per plant and multi-component compound fertilizer of 19.99 g per plant were suitable fertilization methods for the cultivation of one-year-old hybrid S. matsudana × alba.
In order to understand the effects of NaOH concentration (%), chitosan concentration (%) and soaking time on the dynamic changes of soluble sugar and starch during seed germination of Tectona grandis factorial levels and their treatment combinations (TCs) of, the L9(34) orthogonal design was employed to implement the experiment. The above two parameters were measured before sowing （initial） and at 7, 14, 21, 28 days after sowing. The results were as follows: the initial soluble sugar content was 1.39 mg·g-1, and other four stages of the TCs were 0.20-1.44, 0.11-0.70, 0.10-0.63 and 0.15-0.54 mg·g−1, respectively. The soluble sugar content among the treatment combinations after sowing is extremely significant (P<0.01) and significant (P<0.05, 28 d). The initial seed starch content was 0.41 mg·g−1, and the contents of four treatment combinations after sowing were 0.14-2.16, 0.35-0.90, 0.44-0.68 and 0.32-1.01 mg·g−1, respectively. The starch content was significant (P<0.05) or extremely significant (P<0.01-7 d). The chitosan concentration was the dominant factor affecting the change of soluble sugar content, and the optimal TC facilitating physiological activity of soluble sugar of teak seeds was 0.2% chitosan solution presoaking seeds for 12 hours after 3% NaOH concentration solution soaking seed. NaOH concentration was the dominant factor affecting the changes of starch content, and the optimal TC to promote the increase of starch content was soaking in 5%NaOH concentration and then soaking in 0.2% chitosan for 18h.
In order to explore the optimal Phyllostachys praecox density in Phyllostachys praecox-Polygonatum sibiricum intercropping models, three kinds of bamboo density: low density D1 (6000~9000 stems·hm−2), medium density D2 (9000~12000 stems·hm−2) and high density D3 (12000~15000 stems·hm−2) were set in the extensive management of Phyllostachys praecox forest as the test area, and the effects of these three different bamboo density on the growth and development, biomass accumulation and the medicinal value of Polygonatum sibiricum were analyzed. The results showed that the three bamboo densities had different effets on the plant height, ground diameter, biomass, chlorophyll content and leaf relative characteristics of Polygonatum sibiricum. Under D1 density, the aboveground and belowground biomass of Polygonatum sibiricum was the largest, the dry matter content of leaves was the highest, and the dryness rate of aboveground and underground parts was the largest. Meanwhile, there was no significant difference in the total polysaccharide content of Polygonatum sibiricum and the total saponin content of Polygonatum sibiricum under the three bamboo densities. This study clarifies that the bamboo density is an important factor affecting the growth of Polygonatum sibiricum under the Phyllostachys praecox forest, and the suitable bamboo density for the combined management of Phyllostachys praecox-Polygonatum sibiricum is 6000~9000 stems·hm−2.
In order to explain the influence mechanism of the cold island effect in urban parks to alleviate the heat wave under different landscape characteristics, this study explored the response changes of 24 urban parks in Dalian to heat wave environment based on land surface temperature data retrieved by Landsat 8 thermal infrared band. The result showed that heat wave had a significant impact on the land surface temperature. Under the heat wave environment, the change in cooling range (ΔC) of parks ranged from −68.38 to 92.67 m, and the change in cold island intensity (ΔP) ranged from −1.532 to 0.783°C. Different parks had different responses to heat waves. And the changing trends of ΔC and ΔP in the same park were not completely consistent. The important landscape parameters affecting ΔC were forest area ratio, grassland area ratio, and grassland aggregation degree. The important landscape parameters affecting ΔP were surface area ratio, water area ratio, and grassland area ratio. When dealing with the heat wave environment, the urban parks with the resistance type (ΔC>0 and ΔP>0) can better mitigate heat waves, and the forest area ratio was usually more than 48.5%, land surface area ratio was less than 11%, water area ratio was greater than 29%, grassland area ratio was less than 41%, and grassland aggregation degree was less than 97.8%.
In order to understand the effect of different green biomass in communities on regulating thermal comfort. The green biomass and physiological equivalent temperature PET values of 20 quadrats of arbor-shrub-grass community in Minjiang Park（south）of Fuzhou were calculated. And the correlation between green quantity and PET values was analyzed. The results showed that in the arbor-shrub-grass community, when the total green biomass per 100 m2 was less than 800 m3, the greater the green biomass was, the better the effect of community on regulating thermal comfort was. When the total green biomass per 100 m2 was greater than 800 m3, the change of green biomass did not affect the thermal comfort. When the proportion of tree green reached 0.9, the community had the best effect on improving thermal comfort.
Community structure characteristics can reflect the stability, development and renewal trends of community within a certain spatial range. Based on the investigation and analysis of the community species diversity, diameter class structure characteristics and population distribution patterns in the typical sample plots in the south Taihang Mountains, it was found that the highest important value of P. chinensis in the tree layer of the survey area was 59.20, which became the dominant species in the area. The diameter class structure of P. chinensis population and the community structure of the entire survey area showed a typical inverted “J” type, which belong to the population growth type, that is, the community had stronger self-renewal ability, and P. chinensis was stronger. The dominant species such as P. chinensis and Quercus variabilis in the survey area showed an aggregate distribution, while other tree species were randomly distributed. The mean variance ratio (v/m) and aggregation index (Ci) of P. chinensis were as high as 262.37 and 261.37, respectively, which was the highest among all tree species in this investigation area. The results indicated that P. chinensis had higher self-renewal ability and stronger adaptability than other tree species, so a deciduous broad-leaved mixed forest with P. chinensis as the main dominant species was formed in the South Taihang Mountains.
We investigated the effects of temperature, light, and GA3 and their interactions on seed germination of Pinus yunnanensis, an endemic tree to southwest China. The results showed that: (1) The germination rate of P. yunnanensis seed was the highest at 20/5 ℃ and 25/10 ℃ (42% ± 0.30 and 40.25% ± 0.31, respectively), and too high (30/20 ℃) or too low (4 ℃) temperature was unfavorable for Pinus yunnanensis seeds germination. (2) Light had no significant effect on P. yunnanensis seed germination (P>0.05). The seeds of P. yunnanensis can germinate normally under light and dark conditions. (3) Soaking seeds with water could improve the seed germination of P. yunnanensis, but GA3 had no significant effect on germination (P>0.05). (4) Due to the non-dormant nature of P. yunnanensis seeds, sowing in the early spring rainy season in Panxi region was beneficial for seedling establishment. In this paper, the response characteristics of seed germination to various environmental factors were investigated, aiming at understanding the germination characteristics of P. yunnanensis seeds, promoting scientific seed storage, and timely and appropriate seed sowing in afforestation projects, which had important significance for improving the survival rate of ecological restoration afforestation and the preservation rate of young forests in Southwest China.
Maoxian county is a typical dry valley areas in Minjiang river basin, where soil erosion is serious and bare soil is widely distributed. By means of remote sensing and geographic information technology, the spatial and temporal dynamics of bare soil distribution in Maoxian arid valleys since 2000 were analyzed, and the spatial and temporal changes of bare soil on the surface of this area were counted by naked soil index extraction method. The results showed that from 2000 to 2020, the bare soil area in Maoxian arid valley decreased by 4898.7 hm2, mainly concentrated in Shaba town, Goukou town, Diexi town and Fengyi town, with an altitude of 1400-2600 m. During the past 20 years, the bare soil area in arid valley increased first and then decreased gradually, which objectively reflected that the distribution of bare soil in Maoxian dry valley was affected by earthquake disaster and ecological treatment. The analysis indicates that artificial management can significantly reduce the bare soil area in arid valley regions and effectively control soil erosion.
The purpose of this study is to understand the community spatial pattern characteristics of main tree species in Nanling Nature Reserve. Based on the fixed sample plot, the spatial distribution pattern of main tree species in the community was studied through the investigation and analysis of plants in the sample plot. The results showed that there were 104 woody plants belonging to 58 genera, 39 families in the plot. According to the order of important value, 7 species were the dominant species, including Machilus chinensis, Pinus massoniana, Castanopsis eyrie, Cercis chuniana, Daphniphyllum oldhamii, Symplocos congesta, Adinandra bockiana. The distribution of Machilus chinensis was aggregated at 0-2.5 m, random at 2.5-4.0 m, and uniform at 4.0-6.0 m. Pinus massoniana was randomly distributed from 0 m to 25.0 m. The other species showed aggregation distribution in small-scale and random distribution in large-scale. There was no obvious interspecific competition within the community, and there was still a large living space.
In this study, two excellent provenance Eucalyptus cloeziana No.1212 and No.1225 were introduced in Laibin, Guangxi, and the pure Eucalyptus cloeziana forest and the mixed management forest of Eucalyptus cloeziana × Eucalyptus urophylla were built. The results showed that the growth of 2.5-year-old Eucalyptus cloeziana in the compound management forest constructed by provenance No. 1212 was significantly higher than that of the mixed provenance, and provenance No. 1212 was also better than provenance No. 1225 in pure forest. Provenance No. 1212 was more suitable for the climate and soil conditions in Laibin area, and had certain popularization value.
In order to select excellent poplar clones in the mid-altitude mountain area in Southwest Sichuan, further meeting the needs of local afforestation and speeding up the development of poplar industry, 28 poplar clones were introduced respectively, and Butuo county was selected to carry out the seedling test. Using ground diameter and seedling height as indexes, excellent clones suitable for growing in this area were preliminarily selected. By using the methods of variance analysis and multiple comparison analysis, the results showed that there were great differences in seedling growth traits among 1-year-old poplar clones, and Nanlin 312 was the best at seedling stage according to ground diameter and seedling height, which provided a reference for the popularization and application of excellent poplar clones in the mid-altitude mountain area s in Southwest Sichuan.
In this paper, a newly recorded species of Orchidaceae in Sichuan—Herminium handelii X.H. Jin, Schuit., Raskoti & L.Q. Huang was reported. Meanwhile, the rediscovery of both Ponerorchis crenulata (Schltr.) Soó and Crepidium orbiculare (W.W. Smith & Jeffrey) Seidenf. were also reported in Sichuan province. Photos of all three species and their habitats were also provided.
In this paper, six newly recorded species of woody plants in Sichuan Province were reported, namely Deutzia yunnanensis （Saxifragaceae）, Daphne brevituba （Thymelaeaceae）, Berberis taronensis （Berberidaceae）, Schefflera multinervia （Araliaceae）, Nothapodytes tomentosa （Icacinaceae） and Delavaya toxocarpa （Sapindaceae）. Delavaya toxocarpa belongs to the genus Delavaya Franch, which is a monophyletic species. According to relevant documentary records, it is distributed in Guangxi province and Yunnan province in China, and it is also distributed in northern Vietnam. The discovery in Huili city and Panzhihua city confirmed that it is a new genus record in Sichuan province. The voucher specimens were preserved in the Herbarium of Xichang college （XIAS）. The newly recorded discovery not only enriched the diversity of spermatophyte in Sichuan province, but also provided a basis for studying the origin, diffusion routes, and distribution of related groups.
Synotis duclouxii （Dunn） C. Jeffrey & Y. L. Chen was reported as newly recorded species in Guizhou, And the morphological characteristics and habitat distribution were described. The voucher specimen was preserved in the Herbarium of the college of forestry, Guizhou university （GZAC）.
Through specimen inspection and identification, the new record species Styrax rhytidocarpus was reported in Guposhan Autonomous Region Nature Reserve, Hezhou city, Guangxi province. In this paper, the main morphological characteristics and information of newly recorded specimens were provided, the geographical distribution of this species in China was clarified, and the ornamental and application value of this species were discussed.