Study on Environmental Risk and Economic Benefits of Rotation Systems in Farmland of Erhai Lake Basin

This study was designed to find out an optimised planting system of reducing non-point （source） pollution by analyzing the reasons and the factors of influence non-point pollution in farmland of Erhai Lake basin. The results showed that incomes, residual nitrogen in soil, and the loss of nitrogen in surface water in rice-garlic system were higher than those in rice-fava bean system. There were positive correlations between the nitrogen loss of farmland, nitrogen inputs, residual nitrogen in soil, and incomes of farmland. Economic benefits and environment benefits are both appropriate, if the area of rice-garlic system would be reduced to 53% and the area of rice-fava bean system increased to 36% of total cropping area in the investigated watershed. Adjustment of planting structure and introduction of reasonable rotation systems is considered an effective measure of controlling agricultural non-point pollution in watersheds of Erhai Lake.

RECENT SEDIMENTATION AND SUSPENDED MATTER IN ERHAI LAKE,YUNNAN PROVINCE,CHINA

Ths study on the physico-geograpical environment of Erhai Lake focused on the suspended matter and recent deposition rates, 14 C, 210 Pb and 137 Cs methods were used to determine the ageand sedimentation rate, which was found to be 0.5 t0 2.0 mm/a, average of 0.9 mm/a. The authors calculated the budget of some elements by studying the deposition, and fuUnd that about 30% of nitrogen,and most of the phosphorous, were transported into the lake by the ediments.

Analysis on the Space and Architecture of the Bai Settlement in Erhai Area Under the Influence of Han Culture

The influence of the Han culture on the Bai culture in Dali is the greatest and the most profound during the course of the historical development of China for thousands of years. The blending of the Han culture and the Bai culture is a distinctive feature the Bai culture, which is obviously seen in the location and layout as well as the composition and structure of the settlement and architecture of the Bai nationality in the Erhai area of Dali. Additionally, the Bai nationality in Erhai area conformed to nature and adopted nature to create the unique culture and settlement landscape based on the absorption of the cultural thoughts such as the golden mean, respect for seniority and the harmony between man and nature, as well as the advanced skills of the Han nationality. This paper further emphasized the characteristics and laws of Bai culture through the analysis of the Han culture elements in the space and architecture of the Bai settlement in the Erhai area of Dali. It is hoped that this study can provide references for the protection and development of the Bai settlement.

Carnivals between Cangshan Mountain and Erhai Lake

THE Bai people are China’s 15th largest ethnic minority.They live mainly in Yunnan Province,specifically in Dali Bai Autonomous Prefecture,and some in Guizhou and Hunan provinces.Dali is where the Bai people’s ethnic roots are.From the 23rd to 25th day of the fourth lunar month every year,Bai people in Dali pray for

Keep Erhai Lake Clean

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Seasonal dynamics of crustacean zooplankton community structure in Erhai Lake, a plateau lake, with reference to phytoplankton and environmental factors

The seasonal dynamics of a crustacean zooplankton community in Erhai Lake was investigated from May 2010 to April 2011. In total, 11 species were recorded, including six(6 genera) cladoceran and five(5 genera) copepod species. The crustacean zooplankton densities ranged from 24.3 to 155.4 ind./L. In winter and spring, the large-bodied cladoceran Daphnia galeata dominated the crustacean plankton community. In summer and autumn, when the colonial or filamentous algae dominated the phytoplankton communities, the small-bodied species(e.g. B osmina fatalis, Ceriodaphnia quadrangular, and Mesocyclops leuckarti) replaced the large-bodied ones. One-way ANOVA and redundancy analysis revealed that community structure was dependent upon total nitrogen, total phosphorus, water temperature, transparency, and the biomass of small algae. The variation in both phytoplankton structure and environmental variables were important factors in the seasonal succession of crustacean zooplankton structure in Erhai Lake.

Status and historical changes in the fish community in Erhai Lake

<Abstract>Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fish species have been introduced into the lake and the fish community has changed considerably. We evaluated the status of the fish community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition,we evaluated the change in the community using historical data (1952-2010)describing the fish community and fishery harvest. The current fish community is dominated by small-sized fishes, including Pseudorasbora parva, Rhinogobius giurinus, Micropercops swinhonis, Hemiculter leucisculus, and Rhinogobius cliffordpopei. These accounted for 87.7% of the 22 546 total specimens collected.0mnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fishes in the lake is influenced by aquatic plants,water temperature, pH, and season. The abundance of indigenous species hasdeclined sharply, and a majority of endemic species have been extirpated from the lake (adecrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fishery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fish and stocking of native fish. The fishery harvest was significantly correlated with total nitrogen, not total phosphorus,during the past20 years. Based on our results,wediscuss recommendations for the restoration and conservation of the fish resources in Erhai Lake.

Sediment Particle Size Distribution and Its Environmental Significance in Lake Erhai, Yunnan Province

A closed or semi\|closed plateau lake, whose sediment records can provide us with plenty of fine and high resolution information, is a sensitive indicator of climatic and environmental changes. During the reconstruction of various short\|time\|scale climatic and environmental changes, the geochemical records in plateau\|lake sediments are superior to other natural files. Based on fine dissection of the vertical profile of sediment particle sizes, this paper reveals the quasi\|periodical changes of sediment particle sizes, which indicates the quasi\|periodical fluctuations of the regional climate. A synthetic analysis of multiple indexes shows that sediment particle size is a more sensitive and more effective index of climatic and environmental changes than other geochemical indexes. High content of >20 μm sediment particles and low content of 2-10 μm sediment particles indicate a warm\|dry climate and conversely a cold\|humid climate, and their ratio can be used as an effective index of climatic changes. The basic climate succession in the region of Lake Erhai is characterized as being alternatively warm\|dry and cold\|humid and it has been developing into a warm\|dry climate as a whole. There exist at least 2 time\|scale quasi\|periodical fluctuations of the regional climate in Lake Erhai. At present, the region of Lake Erhai is at the end of the warm\|dry period and at the beginning of a cold\|humid period, so the temperature will go down and the water level will rise.

Ectoparasite communities on Tupaia belangeri (Scandentia:Tupaiidae) in surrounding areas of Erhai Lake in Yunnan,China

Objective:To investigate the ectoparasite communities on Tupaia belangeri (T. belangeri) in the surrounding areas of Erhai Lake and their potential importance in medical and veterinary science. Methods: Different locations in surrounding areas of Erhai Lake in Yunnan were selected as the investigation spots. T. belangeri were randomly captured with baited mouse cages and then brought to the laboratory for identification according to their body shape, size and color, and measurements such as the lengths of their body, ear and hind feet. Ectoparasites on them were collected and identified to determine the species under microscope after specimens were mounted on slides, with the clearing and drying process completed. The constituent ratio (C), prevalence (P) and average ectoparasite abundance (A) were used to test the prevalence and density of ectoparasites; Non-parametric Mann-Whitney U-tests were used to test the differences in the abundance and richness of ectoparasites between female and male hosts; Spearman correlation analysis was used to analyze the relationship between ectoparasites and the body parameters of hosts. Results: There was very high species diversity of ectoparasites found on T. belangeri and some species of ectoparasites were reported associated with human diseases. A high proportion (88%) of 107 T. belangeri was found to be infested with ectoparasites. A total of 75 species of ectoparasites on them were collected, including 58 species of chigger mite, 12 species of gamasid mite, 4 species of flea and 1 species of sucking louse. Within this ectoparasite complex, 13 species were previously reported to be vectors of human disease agents. Non-parametric Mann-Whitney U-tests showed significant differences between male and female T. belangeri in terms of the abundance and richness of total ectoparasites. However, the species richness and abundance of chigger mites, sucking lice, fleas or gamasid mites presented no significant differences between male and female hosts. Spearman correlation analysis showed that none of correlations were observed between host body parameters with abundance and richness of total ectoparasites, chigger mites, suckinglice, fleas or gamatid mites. Conclusion: The results suggest that there is very high species diversity of ectoparasites on T. belangeri, consisting mainly of communities of sucking lice, fleas, chiggers and gamasid mites.

苍山洱海国家级自然保护区土地利用格局

目的:了解云南苍山洱海国家级自然保护区(以下简称“保护区”)土地利用结构及特征,掌握土地利用的景观格局,为保护区整合优化及后期管理提供指导。方法:以相关调查数据为基础,基于GIS技术,对保护区土地利用现状、景观格局及矛盾冲突进行分析。结果:苍山片区以林地和草地为主(面积占比96.43%),洱海片区以水体为主(面积占比98.02%);研究区域林地、水域和草地景观形状较为规整,景观破碎度较低,受人为干扰较少;保护区的景观多样性较丰富,但分布不均;保护区各类矛盾冲突图斑面积占保护区总面积的2.44%,矛盾冲突地块主要分布于缓冲区和实验区,以耕地和集体人工商品林为主,采矿用地、城镇建成区和村庄对保护区的影响程度最大。结论:保护区土地结构较为合理,苍山片区管理上要以森林防火、生物多样性保护、地质遗迹保护为主;洱海片区要以湿地保护,特别是水体质量维护和提升,以及水生动植物保护为主。

南诏国的两个地震神话

南诏国(738—902)有两个地震神话传世:一为观音大士镇伏巨鳌,令其长眠不醒,但允其七十至九十春可醒片时。巨鳌醒时眨眼,仍会地动山摇,以致每七十余年地震一次,每四百年大震一次。因此,在望海台树立地震碑,告诫后人要警惕震害。二为洱海河神段赤诚预报地震:今夜亥时,地将大动,十室九倒。为保民平安,遂与两位山神、河东渔夫分工合作:两山神分别变化为鸡与犬,狂鸣、惊跳,以警醒万民;河东渔夫向洱海东部村民报告,洱海河神变化为老叟向西部村民报告。十有九成的村民离开房舍,避于平坦之地,人畜皆安;不相信预报的百余人,皆遭震害。

洱海周边面山植物区系特征调查研究

针对洱海周边面山选取了典型样地31个,采集到洱海周边面山植物475种,隶属于335属、121科。调查及标本鉴定结果表明:洱海面山带有维管束植物(除栽培)100科、294属、403种。其中蕨类植物8科15属21种;裸子植物1科1属1种;被子植物91科278属381种:其中单子叶植物16科63属82种;双子叶植物75科215属299种。对调查区的维管束植物科属区系组成进行分析,指出了植物科属泛热带和热带区系成分明显,这将为后期对洱海面山植被恢复选取树种提供参考,也为进一步加强洱海的保护及其合理开发利用提供理论依据。

典型挺水植物应用于湿地生态修复工程污染净化效应差异性研究

以洱海流域北部上游东湖片区库塘湿地中水生植物为研究对象,选取5种主要水生植物,寻求净化湿地水质的最佳植物组合。结果表明:东湖片区库塘湿地水体总磷、总氮、氨氮、化学需氧量分别为0.09~0.23、0.80~3.28、0.18~0.89、12.00~37.00 mg/L,总体符合《地表水环境质量标准》(GB 3838—2002)中Ⅳ类要求;综合比较发现,植物组合群落生物量和碳氮磷累积效应优于单一植物;植物组合对水体碳氮磷具有一定的吸收净化作用。

苍山洱海国家级自然保护区森林资源动态

目的:了解云南苍山洱海国家级自然保护区(以下简称“保护区”)森林资源近20年的动态变化特征,为保护区编制经营管理方案提供指导。方法:以2005、2015年森林资源调查矢量数据、2021年森林、草原、湿地监测数据、第三次全国土地调查数据为基础数据,基于GIS技术,分析保护区森林资源动态。结果:保护区土地利用类型中,有林地面积最大,并逐年增加;林地中,3个调查年度均以有林地和灌木林地为主,面积占保护区总面积的60.82%以上;保护区森林覆盖率2005—2015年间逐年增加,2015—2021年间增加值逐步趋于稳定;蓄积量以有林地蓄积为主,并逐年增加;乔木林地面积和蓄积量以栎类、云南松、华山松和苍山冷杉为主,且逐年增加;乔木林地中幼龄林、中龄林、近熟林和成熟林比重相对均衡,过熟林面积较少;各年度郁闭度等级均以中为主,且郁闭度等级为中和密的乔木林地面积和蓄积量均逐年增加。结论:保护区森林质量和生态防护功能逐年提高,后期森林资源管理以增加栎类等阔叶林为主。

Lake sediment records on climate change and human activities since the Holocene in Erhai catchment, Yunnan Province, China

According to high-resolution analyses on multi-proxy of sediment core from the Er- hai Lake, Yunnan Province, the sequence of climatic and environmental change since the Holo- cene has been reconstructed based on accurate dating. The results show that climate had tran- sited from cold-wet to warm-wet during ca. 12950-8399 aBP in this area, and the transition happened in ca. 10329 aBP. Due to the enhancing southwest Asian monsoon and increasing precipitation, the lake-level of the Erhai Lake began to rise after ca. 10329 a BP. Climate in the catchment was warm and wet during the mid-Holocene, and the warmest stage appeared in ca. 8399-6371 a BP. The lake-level descended in the mid-Holocene because of the decrease of effective moisture in the basin. Human activities appeared in ca. 6371 a BP, and the initial man- ner mainly focused on deforestation. Up to ca. 2139 a BP, due to the amount of immigration into this area, the cultivation was developed widely, which was followed by mining (coal mine).

Sedimentary record of polycyclic aromatic hydrocarbons in Lake Erhai,Southwest China

The temporal distribution of polycyclic aromatic hydrocarbons （PAHs） was investigated in a sediment core from Lake Erhai in Southwest China using gas-chromatography/mass spectrometry （GC/MS） method. The total organic carbon （TOC） normalized total PAHs concentrations （sum of US Environmental Protection Agency proposed 16 priority PAHs） ranged from 31.9 to 269 ixg/g dry weight （dw）, and were characterized by a slowly increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments. The PAHs in the sediments were dominated by low molecular weight （LMW） PAHs, suggesting that the primary source of PAHs was low- and moderate temperature combustion processes. However, both the significant increase in high molecular weight （HMW） PAHs in the upper sediments and the vertical profile of diagnostic ratios pointed out a change in the sources of PAHs from low-temperature combustion to high-temperature combustion. The ecotoxicological assessment based on consensus-based sediment quality guidelines implied that potential adverse biological impacts were possible for benzo（ghi）perylenelene and most LMW PAHs. In addition, the total BaP equivalent quotient of seven carcinogenic polycyclic aromatic hydrocarbons （BaA, CHr, BbF, BkF, BaP, DBA and INP） was 106.1 rig/g, according to the toxic equivalency factors. Although there was no great biological impact associated with the HMW PAils, great attention should be paid to these PAH components based on their rapid increase in the upper sediments.

Environmental evolution and southwest monsoon changes in mid-Holocene recorded by lake sediments in Erhai Lake

IN recent years, much progress has been made in the research of the temporal and spatial changes of East Asian monsoon. To research the environmental evolution and monsoon variations in Holocene in the region of Southwest China, a 310-cm continuous lake sediments core in Erhai Lake, Yunnan Province was sampled with Livingston sampler on July 6, 1996. The lake sediments were separated at 2-cm intervals and the core samples were analyzed with chronology, stable isotope ratios of organic carbon and diatoms determination. Three 14C ages are （4 473±40）a B.P. （98—102 cm）, （5 825±85） a B. P. （144—148 cm） and （7 754±45） a B.P. （198—202 cm）. By 137Cs dating, the sedimentation rate is about 0.3 mm/a and this result is close to the 14C dating results. The average sedimentation rates

降雨事件下洱海北部主要入湖河流污染物特征分析

通过研究2019年雨季(7—9月)洱海最主要的入湖河流污染物特征,对流域内6场次降雨下的污染物浓度与负荷进行监测,阐述6种污染物特征,计算入湖负荷,并评估对洱海的水质影响。结果表明:弥苴河是北三江流域径流与污染物入湖的主要贡献来源,径流量占北三江流域入湖总径流量的47%,氨氮、硝态氮、可溶性总氮(TDN)、正磷酸盐、可溶性总磷(TDP)和化学需氧量(COD)入湖负荷分别占总负荷的40.5%、65.0%、55.0%、55.0%、54.1%、57.1%;TDN、TDP、氨氮、COD污染负荷之间都存在着不同程度的相关性,降雨是影响氮磷等典型污染物负荷入湖的主要因素。雨季径流携带大量养分入湖使水体养分浓度升高,导致水体环境质量下降。因此在雨季控制径流携带污染物入湖,对防控洱海水质持续下降具有重要意义。

基于GEE的洱海流域土地利用/覆被分类算法对比研究

快速准确地进行复杂高原山区的土地覆被长时序自动分类,可为国土规划、资源利用提供依据。利用GEE云平台,选取Landsat影像地表反射率、植被指数、水体指数、DEM 4种空间数据集作为土地覆被分类的基础和辅助数据,分别运用CART、RF和SVM 3种分类算法,实现洱海流域土地覆被信息的自动提取和精度对比。结果表明:(1)3种分类算法中,RF的总体分类精度最高,SVM的总体精度最低;RF是洱海流域LULC的最适宜分类算法。(2)采用光谱指数、地形特征等辅助数据集会进一步提高解译精度,而样本点的选取是最主要的影响因素。(3)Erhai_RF能够达到较高的精度,同时更加突出细节特征,在局部实际分类精度上会更高。研究结果可为洱海流域长时序土地覆被数据产品智能快速提取以及最优分类算法筛选提供方法和技术支撑。