南方丘陵山区生态安全格局构建与优化修复——以瑞金市为例

构建科学合理的生态安全格局、落实生态保护修复与空间优化是促进区域生态系统健康运行和社会经济可持续发展的重要途径。以南方丘陵山区瑞金市为例,综合生态敏感性评价与最小阻力模型,解构瑞金市生态安全格局及其自然生态与社会经济特点,并提出生态保护修复与空间优化方案。结果显示：(1)瑞金市生态源地共有123.22km~2,占总国土面积5%,主要为重要山林地和水域,环绕中部盆地呈卫星状分布;(2)潜在廊道119条,生态节点72个,在周边山地呈闭合网络状,但中部盆地廊道单一、节点密集,网络连通性较低;(3)瑞金市是典型的高原型阻力面,中部盆地城镇发展区、沟域经济延伸带、西部工矿挖采点生态阻力高、源地辐射弱,应生态预警与重点修复。瑞金市生态保护修复与空间优化应宏观统筹、分区推进、精细落实,划分生态修复核心区、生态监测预警区、生态保护缓冲区和生态保护重点区,明确空间管控原则、分区推进生态保护,围绕“源地-廊道-节点”落实生态修复。     

两种统计方法在玉米种质综合评价中的应用

以玉米为研究对象,运用灰关联分析和因子分析对10份玉米种质的12个农艺性状进行综合评价,探讨这两种统计分析方法在玉米种质综合评价上的应用效果。结果表明,综合评价较好的2个品种分别是Suwan1和下层云优78,两种分析方法的结果基本一致,从而提高了综合评价的可靠性和科学性。     

High-pressure processing – effects on microbial food safety and food quality

High-pressure processing (HPP) is a nonthermal process capable of inactivating and eliminating pathogenic and food spoilage microorganisms. This novel technology has enormous potential in the food industry, controlling food spoilage, improving food safety and extending product shelf life while retaining the characteristics of fresh, preservative-free, minimally processed foods. As with other food processing methods, such as thermal processing, HPP has somewhat limited applications as it cannot be universally applied to all food types, such as some dairy and animal products and shelf-stable low-acid foods. Herein, we discuss the effects of high-pressure processing on microbial food safety and, to a lesser degree, food quality.     

Selecting predictors for discriminant analysis of species performance: an example from an amphibious softwater plant

Selecting an appropriate variable subset in linear multivariate methods is an important methodological issue for ecologists. Interest often exists in obtaining general predictive capacity or in finding causal inferences from predictor variables. Because of a lack of solid knowledge on a studied phenomenon, scientists explore predictor variables in order to find the most meaningful (i.e. discriminating) ones. As an example, we modelled the response of the amphibious softwater plant Eleocharis multicaulis using canonical discriminant function analysis. We asked how variables can be selected through comparison of several methods: univariate Pearson chi-square screening, principal components analysis (PCA) and step-wise analysis, as well as combinations of some methods. We expected PCA to perform best. The selected methods were evaluated through fit and stability of the resulting discriminant functions and through correlations between these functions and the predictor variables. The chi-square subset, at P < 0.05, followed by a step-wise sub-selection, gave the best results. In contrast to expectations, PCA performed poorly, as so did step-wise analysis. The different chi-square subset methods all yielded ecologically meaningful variables, while probable noise variables were also selected by PCA and step-wise analysis. We advise against the simple use of PCA or step-wise discriminant analysis to obtain an ecologically meaningful variable subset; the former because it does not take into account the response variable, the latter because noise variables are likely to be selected. We suggest that univariate screening techniques are a worthwhile alternative for variable selection in ecology.     

Static magnetic field effects on human subjects related to magnetic resonance imaging systems

Goal: This paper reviews recent studies evaluating human subjects for physiologic or neuro-cognitive function adverse effects resulting from exposure to static magnetic fields of magnetic resonance imaging systems.

Materials and Methods: The results of three studies are summarized. Two studies evaluated exposure to a maximum of 8 Tesla (T). The first series studied 25 normal human subjects’ sequential vital signs (heart rate, blood pressure, blood oxygenation, core temperature, ECG, respiratory rate) measured at different magnetic field strengths to a maximum of 8 T. A second series of 25 subjects were studied at 0.05 and 8 T (out and in the bore of the magnet), performing 12 different standardized neuro-psychological tests and auditory–motor reaction times. The subjects’ comments were recorded immediately following the study and after a three-month interval. The third study contained 17 subjects, placed near the bore of a 1.5 T magnet, and it used six different cognitive, cognitive–motor, or sensory tests.

Results: There were no clinically significant changes in the subjects’ physiologic measurements at 8 T. There was a slight increase in the systolic blood pressure with increasing magnetic field strength. There did not appear to be any adverse effect on the cognitive performance of the subjects at 8 T. A few subjects commented at the time of initial exposure on dizziness, metallic taste in the mouth, or discomfort related to the measurement instruments or the head coil. There were no adverse comments at 3 months. The 1.5 T study had two of the four neuro-behavioral domains exhibiting adverse effects (sensory and cognitive–motor).

Conclusions: These studies did not demonstrate any clinically relevant adverse effects on neuro-cognitive testing or vital sign changes. One short-term memory, one sensory, and one cognitive–motor test demonstrated adverse effects, but the significance is not clear.     

山东省农田防护林生态系统服务功能价值核算

研究农田防护林生态系统服务功能价值对于区域经济的发展和生态环境的保护具有重要意义。运用市场价值法、机会成本法、影子价格法等,对山东省2001和2005年农田防护林生态服务功能价值进行了核算。结果表明:2001和2005年农田防护林生态服务功能的总价值分别为95.83亿元和124.97亿元,各项生态服务指标的价值顺序为保育土壤>作物增产>生物多样性保护>固碳供氧>净化空气;生态服务的总价值年均增加7.29亿元,其中保育土壤的价值增加最大为3.23亿元,其余依次是作物增产、生物多样性保护、林产品、固碳供氧、净化空气,增加价值分别为2.19、1.25、0.56、0.05、0.01亿元。因此,农田防护林具有的生态服务功能价值是巨大的,应该尽快建立生态服务市场补偿机制和完善生态服务功能价值评估方法,促进农田防护林从生态型向生态经济型转变。     

基于Lake模型的叶绿素荧光参数在甘蔗苗期抗旱性研究中的应用

为从能量平衡及分配的角度研究干旱胁迫下甘蔗(Saccharum officinarum)苗期光系统的运转状况, 进而为丰富不同甘蔗品种的抗旱性评价指标及实现对季节性干旱胁迫的快速诊断提供理论依据, 该研究通过对基于Lake模型的叶绿素荧光参数在不同入射光强下变化的动态分析, 研究光合电子传递链中能量平衡状态对不同水分梯度(40%、25%、10%、8%)的响应。结果表明: 两个供试品种(耐旱品种‘ROC22’和非耐旱品种‘ROC16’)的最大光能利用效率(F_v/F_m)、相对电子传递速率(rETR)、光系统II(PSII)量子效率(Φ_II)和光化学猝灭(q_L)均随着干旱胁迫程度的增加而下降, 可调节性能量耗散(Φ_NPQ)和非调节性能量耗散(Φ_NO)则随着干旱胁迫程度的增加而上升。除Φ_NO之外的叶绿素荧光参数的变化幅度均随着光合有效辐射(PAR)的增加而增大。在干旱胁迫的前中期, 相对于‘ROC22’, ‘ROC16’的PSII反应中心能够维持较高的开放程度; 但‘ROC22’调节能量耗散的能力和对干旱胁迫的敏感程度均高于‘ROC16’, 说明较强的光保护能力是‘ROC22’的抗旱性高于‘ROC16’的主要原因之一。对干旱胁迫敏感且在不同PAR下较为稳定的Φ_NO可作为甘蔗苗期抗旱性的快速诊断和评价指标。rETR对递增的PAR的响应表现为随着干旱胁迫程度的增加而提前出现峰值或下降趋势, 但是不同水分梯度下的rETR在PAR较低时并无显著差异, 表明干旱胁迫下光抑制现象的提早出现是造成光系统损伤的首要因素, 高光强对干旱胁迫信号起放大作用。     

Seeing the Forest for the Trees: Integrated Conservation and Development Projects and Local Perceptions of Conservation in Madagascar

This paper explores local perceptions of internationally financed conservation and development projects in Madagascar and the success of these projects at influencing perceptions. Interviews, surveys, and focus group sessions were conducted in the peripheral zones of three Malagasy national parks: Ranomafana, Andohahela, and Masoala. Relevant questions explored community demographics, socioeconomic status, and local perceptions of the parks. The principal finding is that while a majority of people living in the peripheral zones do find conservation a valuable goal, they see it as a luxury they cannot afford. Despite their efforts and innovation, conservation and development projects have had a minimal impact on socioeconomic or associational life in the Ranomafana and Andohahela peripheral zones, and a significant but modest impact in the Masoala peripheral zone, by providing economic alternatives to destructive resource use. As a result, they are limited in their success at promoting conservation outcomes.