Seasonal and diurnal gas exchange differences in ozone-sensitive common milkweed (Asclepias syriaca L.) in relation to ozone uptake

Stomatal conductance and net photosynthesis of common milkweed (Asclepias syriaca L.) plants in two different soil moisture regimes were directly quantified and subsequently modeled over an entire growing season. Direct measurements captured the dynamic response of stomatal conductance to changing environmental conditions throughout the day, as well as declining gas exchange and carbon assimilation throughout the growth period beyond an early summer maximum. This phenomenon was observed in plants grown both with and without supplemental soil moisture, the latter of which should theoretically mitigate against harmful physiological effects caused by exposure to ozone. Seasonally declining rates of stomatal conductance were found to be substantial and incorporated into models, making them less susceptible to the overestimations of effective exposure that are an inherent source of error in ozone exposure indices. The species-specific evidence presented here supports the integration of dynamic physiological processes into flux-based modeling approaches for the prediction of ozone injury in vegetation.     

东北老工业区环境与经济可持续发展的研究

为保证我国东北老工业区的社会、经济、环境全面协调可持续发展,从东北老工业区的概况,社会、经济、环境问题的现状入手,对其社会系统、经济系统和环境系统在地区发展中面临的困境和主要问题进行了分析;立足于系统科学的角度,从社会、经济、环境3个系统方面,为东北老工业区提出了协调可持续发展的宏观建议。     

天津滨海新区秋冬季大气污染特征分析

为了解天津滨海新区大气污染物浓度水平和污染来源,2009年9月1日~2010年2月28日对NOx、CO、SO2、O3、PM2.5、PM10进行了连续在线观测,并同步观测了气象要素.结果表明,秋冬季上述污染物最高日均值(秋冬平均值±标准差,O3为日小时均值最大值)分别达到300.7(65.4±52.9)×10-9、7.278(1.324±1.169)×10-6、53(13±12)×10-9、95(28±21)×10-9(体积分数)和287.4(62.3±53.6)μg/m3、1421.4(161.9±136) μg/m3. NOx和SO2秋季低于冬季,O3和PM10反之. CO和PM10相对国家二级标准超标率为2%和38%,PM2.5相对WHO标准(75μg/m3)超标率为31%.季节统计日变化显示CO和NOx为早晚双峰型,SO2为中午的单峰型,O3为午后单峰型,且秋季日变化振幅远大于冬季, PM10为早晚双峰型,但冬季比秋季晚出峰2~3h.除冬季PM10,大气污染物浓度49%~74%的逐日变化由气象要素影响.滨海新区大气污染受局地排放和外源输送共同影响,西南方向气流易造成污染物积累,其次是东北方向,而东和东南气流最有利于污染物扩散;各污染物具体表现为NOx主要受局地源控制;SO2主要受外来输送影响;CO和PM2.5同时受本地源和外来源的共同影响;PM10秋季表现为本地源污染,而冬季为本地源和外来源的共同影响.     

基于粗糙集和支持向量机的标准农田地力等级评价

标准农田是耕地的精华,是确保国家粮食安全的关键。科学评价标准农田地力等级对标准农田培肥和土壤改良有着重要意义。将粗糙集(Rough Set,RS)理论和支持向量机(Support Vector Machine,SVM)相结合,提出了基于RS和SVM的标准农田地力等级评价方法,同时,利用遗传算法的并行搜索结构和模拟退火的概率突跳特性,提出了GASA优化SVM参数算法。该方法首先在确定标准农田地力等级评价指标的基础上,利用地力调查样本数据及传统的指数和法评价结果构建RS决策表,应用RS穷尽算法对决策表进行约简,剔除冗余的评价指标,然后用约简后的评价指标作为SVM的输入,运用GASA优化SVM参数算法对SVM进行训练,建立标准农田地力等级的RS-SVM评价模型。应用该方法对温州市鹿城区标准农田地力等级进行评价,与未用RS约简的SVM模型和BP神经网络模型评价结果进行对比,SVM模型和BP神经网络模型的输入指标数均为15个,其评价正确率分别为100%和90%;RS-SVM模型的输入指标数为14个,其评价正确率分别为100%,结果表明,该方法通过RS约简评价指标后,SVM评价精度并没有降低,但降低了SVM输入向量维数和计算复杂度,提高了训练效率;SVM 用于标准农田地力等级评价,具有比BP神经网络更高的评价精度,可有效用于标准农田地力等级评价,为耕地地力评价提供了新方法。     

综合危险性指数法在泰山区地质灾害易发区划分中的应用

地质灾害易发区划分是进行地质灾害防治的基础工作。针对泰安市泰山区地质灾害分布特点,进行区内地质环境特征和危险性分析以及综合危险性指数(含潜在地质灾害强度指数和现状地质灾害强度指数)计算,对区内地质灾害易发程度进行定量评价,将泰山区划分成地质灾害高易发区、中易发区、低易发区和不易发区等4个等级,为今后开展地质灾害防治提供依据。     

滨海新区湿地生态系统服务功能价值评估

滨海新区湿地类型多样,作为滨海新区生态环境与景观生态的基质,对其区域生态、景观生态及经济发展具有重要影响。以滨海新区湿地为研究对象,在实地调查的基础上,综合采用市场价值法、影子工程法、条件价值法等评估方法,对其生态系统服务功能价值进行估算。结果表明,滨海新区湿地生态系统服务功能价值为4 276.77亿元,其中直接使用价值、间接使用价值和非使用价值分别为412 594万元、40 411 851万元和1 943 256万元。因此,滨海新区湿地对维持当地可持续发展具有举足轻重的作用,在滨海新区湿地资源管理和开发利用的过程中,应充分发挥湿地资源的生态功能,促进区域经济的可持续发展。     

大连金州新区并区前后的生态适宜度分析

开发区扩区或与行政区合并是近年来开发区二次创业的发展趋势,有必要对并区前后的土地利用和产业布局合理性进行评估。应用层次分析法和专家打分法分析了大连金州新区并区前后的生态适宜度。结果表明:原金州区的工业区和居住区在合并前后生态适宜度得分从63.75分和60.25分上升到82.75分和85.75分;经济技术开发区工业区和居住区从82.75分和77分上升到82.75分和85.75分。均从不适宜、适宜上升到很适宜。     

武汉市洪山区夏季PM2.5浓度、水溶性离子与PAHs成分特征及来源分析

2014年6月12日~7月22日,在武汉市洪山区进行PM2.5采样,分析了夏季PM2.5及其水溶性离子的浓度,并利用气相色谱/质谱(GC/MS)对PM2.5中多环芳烃(PAHs)浓度进行测定,探讨其污染来源及形成机制.结果表明,PM2.5质量浓度为36.41~220.02μg·m-3,平均值为97.38μg·m-3,超标率为59.26%,气象因素中风速对其影响较大,随着风速的增加,浓度呈降低趋势;SO2-4、NO-3、NH+4和K+是PM2.5的主要组成成分,占PM2.5质量浓度的40.67%,气溶胶偏酸性;对SO2-4、NO-3的形成过程分析发现其所受的影响因素不同,PM2.5中NH+4主要以NH4HSO4和(NH4)2SO4的形式存在.PM2.5中PAHs日均质量浓度为11.30 ng·m-3,主要是以4、5、6环为主.对PM2.5来源进行分析表明工业废气及汽车尾气的排放为主要污染源,其中燃煤及汽车尾气占83.90%,石油源占10.17%,炼焦排放占5.08%.PAHs总毒性当量浓度(TEQBa P)值为0.22~11.19ng·m-3,平均值为1.74 ng·m-3,日均超标率7.41%.     

Predicting Periphyton Cover Frequency Distributions across New Zealand's Rivers

Regression models of mean and mean annual maximum (MAM) cover were derived for two categories of periphyton cover (filaments and mats) using 22 years of monthly monitoring data from 78 river sites across New Zealand. Explanatory variables were derived from observations of water quality variables, hydrology, shade, bed sediment grain size, temperature, and solar radiation. The root mean square errors of these models were large (75‐95% of the mean of the estimated values). The at‐site frequency distributions of periphyton cover were approximated by the exponential distribution, which has the mean cover as its single parameter. Independent predictions of cover distributions at all sites were calculated using the mean predicted by the regression model and the theoretical exponential distribution. The probability that cover exceeds specified thresholds and estimates of MAM cover, based on the predicted distributions, had large uncertainties (~80‐100%) at the site scale. However, predictions aggregated by classes of an environmental classification accurately predicted the proportion of sites for which cover exceeded nominated criteria in the classes. The models are useful for assessing broad‐scale patterns in periphyton cover and for estimating changes in cover with changes in nutrients, hydrological regime, and light.     

Action research and residential waste minimisation in Palmerston North,New Zealand

This research adds an action research approach to mixed methods to understand the drivers and barriers to residential waste minimisation in Palmerston North, New Zealand. While local, national, and global structural barriers persisted outside the participants’ immediate control, action research enhanced waste minimisation practices within the limits of these structural barriers. The reflexive and collaborative principles of action research allowed research participants to identify individualised needs and challenges. Thus, the research proceeded according to the participants’ circumstances. Some of the key drivers included a sense of accountability, active learning, social support, convenience, affordability, and access to information and resources. The participants also offered recommendations to the City Council, producers, and policy-makers to enhance residential waste minimisation in Palmerston North. While the value-action gap persists in purely quantitative waste research seeking to understand and change waste behaviour, action research was beneficial as it added a more nuanced understanding of participants’ waste behaviours. It also contextualised waste-related practices and attitudes in a specific locale.