降水对高寒草甸草原植被盖度及地上生物量的影响

降水量决定了植被生长的水分条件,是决定植被生产力的有效指标。本研究以甘肃省天祝藏族自治县高寒草甸草原为研究对象,研究多年采集的地上生物量数据与年度降水量,分析降水量对草原地上生物量的影响。研究表明:在高寒草甸生态系统中,春季降水是植物生长的重要影响因子,而夏季降水也是一个关键因素,一定幅度的增加或减少不会影响群落地上生物量积累;而降水量过大,由于气温较低,植被光热需求不能保障,群落地上生物量积累则会减少。通过分析,1~4月份降雨量60~70 mm之间,5~8月份降雨量在200~270 mm之间,高寒草甸草原牧草长势最佳,产草量较高。可以据此在未来气候变化背景下,通过预测年度降水量来预测年度草原生产力,为天然草原核定载畜量提供科学依据。

基于C5.0与Apriori算法的森林生物量等级评价与因子关联分析

针对生物量影响因子量化研究较少、方法单一及区域生物量评价不足且基于单个树种生物量模型进行评价时工作量过大的问题,以孟家岗林场的三类小班清查数据为基础,选取与生物量水平相关的11个因子,利用C5.0算法进行生物量决策树建模,并进一步利用Apriror算法进行生物量强影响因子的关联规则挖掘。结果表明:生物量决策树模型的分类预测精度为88.78%,生物量影响因子的量化结果分别为树高(0.348)、胸径(0.225)、林分类型(0.196)、龄级(0.162)、郁闭度(0.134)、坡度(0.096)、海拔(0.074)、坡向(0.065)、立地类型(0.052)和坡位(0.037);得到707条置信度在80%以上、支持度在10%以上的因子关联规则,揭示了生物量影响因子间的隐含关联关系。建立的生物量决策树模型能为快速的区域生物量预测和评价提供模型参考,建立的关联规则评估模型能够为以碳汇为目标的森林生产与经营提供客观评价指标。

堤防工程对水产种质资源保护区的影响分析及应对——以南浦溪为例

通过调查水产种质资源保护区现状,分析水利工程建设对水产种质资源保护区的影响,估算堤防工程建设对保护区鱼类生物量的损害程度,并提出合理施工、生态修复、增殖放流、跟踪监测等保护对策,以期促进水利工程中河湖生态保护的提升,推动水利项目高质量发展。

Optimization of the Technique for Liquid Culture of Pleurotus cornucopiae Seeds

[Objective] This study aimed to optimize the conditions for liquid culture of P. comucopiaeseeds. [Method] ＂P. cornucopiae 2＇ selected by our laboratory was used as the experimental strain in this study. Single factor experiment in conjunction with Plackett-Burman （PB） design as well as Response Surface Methodology（RSM） based on Central Composite Design （CCD） were used to screen and optimize the eight factors influencing the technique for liquid culture of P. cornucopiae seeds. [Result] Firstly, the eight factors influencing the biomass of P. cornucopiae seeds in liquid culture were confirmed by means of single factor experiment; secondly, through Plackett-Burman experiment design, three main factors influencing the biomass of P. cornucopiae seeds in liquid culture were screened, namely the amount of added mannitol, the initial pH and culture temperature; lastly, the second order model, that is Y=-70.72＋2.44X3 ＋2.67X7 ＋3.72X8 ＋0.08X3 X7 -0.01X7 X8-0.05X32- 0.34X72-0.08X82, was obtained through Central Composite Design （CCD） along with Response Surface Methodology （RSM）. [Conclusion] The optimal conditions for the production of P. cornucopiae seeds in liquid culture were as follows： the amount of added mannitol of 28.17 g/L, the initial pH controlled at 5.90, 250 ml erlenmeyer flask filled with 100 ml of liquid medium, inoculum size of 5%（v/v）, rotation speed of 150 r/min, and gyratory culture at 23.97℃ for 5 days.

Study on Zymomonas Mobilis Growth and Its Relationship with Glutaminase Production by Using Statistical Tools

Glutaminase is used industrially to enhance flavor and aroma and to enrich foodstuffs nutritionally. It also has potential for pharmaceutical application as anti-leukemia agent. The bacteria of Zymomonas mobilis has been studied for ethanol production, however, there is no study regarding glutaminase production. The aim of the present study was to establish the influencing factors for the growth of Z mobilis and its relationship with glutaminase production using statistical tools. Analysis of variance in blocks was carried out in a complete block design and the Tukey test demonstrated the importance of the components of the culture medium, absence of agitation and fermentation time. Minimum culture medium was used in the optimization varying the glucose concentrations （10, 30, and 50 g/L）, glutamine （0, 0.5 and 1g/L） and culture time （18, 24 and 30 hours）. Maximum production was obtained at 8.86 U/L glutaminase. Optimized conditions were used in the growth kinetics, where typical exponential growth was observed. Glutaminase production was shown to be related to biomass production.

Protection status as determinant of carbon stock drivers in Cerrado sensu stricto

Aims Natural vegetation plays an important role in global carbon cycling and storage.Thus,the Cerrado(Brazilian savannah)is considered a carbon sink because of its intrinsic characteristics.Our aim was to evaluate how the aboveground biomass and biodiversity relationship change between three Cerrado remnants with different protection status:a‘control area’(Legal Reserve area),a protected area(PA)and a non-protected area(Non-PA).Methods All three studied fragments are situated in northern Minas Gerais state,Brazil.We estimated the aboveground carbon stocks based on the forest inventory.We also measured three dimensions of biodiversity metrics for each plot:functional trait dominance,taxonomic diversity and functional diversity.The following functional traits were evaluated for the species:wood density,maximum diameter and seed size.We carried out generalized linear models seeking to evaluate how carbon stocks,community-weighted mean(CWM)trait values,species richness and diversity,and functional diversity indices differ among the remnants.Important Findings The Cerrado areas without protection status had lower carbon stocks,species richness,species diversity,functional richness and functional dispersion,whereas both PA and Non-PA had lower CWM maximum diameter and seed size compared with the Legal Reserve control area.Generalized linear models showed that carbon stocks,species and functional richness metrics were correlated within and across sites,and thus,species richness could serve as a good proxy for functional richness and carbon stocks.The carbon stocks were positively driven by species richness and CWM maximum diameter,while they were negatively driven by functional dispersion.Functional richness,species diversity and CWM seed size appeared in the set of best models,but with no significant direct effect on carbon stocks.Thus,we concluded that absence of protection in the Cerrado areas decreases both species richness and carbon stocks.