赤峰市生态文明气象保障服务现状分析

本文以赤峰市生态环境现状出发,利用气象资料、卫星遥感数据进行分析,深入剖析了赤峰市生态文明气象保障服务现状、存在的问题,并提出了几点解决对策,为进一步提升气象服务能力和助力赤峰市生态文明建设提供参考。     

The effect of exposure on landscape scale soil surface temperatures and species distribution models

Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations, dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme temperatures (summer maximums, winter minimums). The correlation (r ²) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for 37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain the patchy distribution of many species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

基于SPOT5图像的小城市城区绿地系统景观异质性分析——以邹城市为例

以邹城市建成区为研究对象,以邹城市2006年的SP015遥感影像为信息源,通过ERDAS IMAGINE8．5对图片进行处理,利用Ar-cview GIS图像、数据处理功能,获取景观要素图斑,计算景观格局的异质性指数。结果表明,景观多样性指数相对较高。邹城城区绿地系统的景观优势度较小,均匀度较大。绿地面积分布较为均衡,但是各类型绿地分布并不均衡。通过对景观异质性指数的分析,探讨了小城市景观生态空间格局,提出了城市景观生态优化的对策和措施。     

近20年宝鸡市植被覆盖度动态变化及驱动力分析

植被覆盖度是反映地区生态环境的重要指标,本文利用1988、2000、2007年三期TM遥感数据,计算出宝鸡市的归一化植被指数(NDVI),并通过像元二分模型计算出不同时段的植被覆盖度,最后将归一化植被指数的差值进行分级,以此来分析宝鸡市1988~2007近20年的植被覆盖变化动态。结果表明:1988~2000年间,极低覆盖度、高覆盖度、极高覆盖度比例都呈现出减少趋势,减少比例分别为宝鸡市土地面积的0.02%、1.66%和1.98%,其他各级别植被覆盖度也都有不同程度下降;2000~2007年间,极高植被覆盖度增大的比例达到8.04%。NDVI差值指数分级结果显示,1988~2000年植被退化明显,2000~2007年有大幅度改善;从长时间序列看,生态退化比较明显的区域是金台区、扶风县、岐山县、凤翔县。人为因素是影响植被覆盖变化的主要驱动因素,主要包括山区或平原区的生态绿化工程、城市景观绿化工程、农业产业结构调整、畜牧业发展、人口因素等。     

长江上游绵阳官司河流域低山丘陵区不同植被类型生物多样性分析

本文用多样性指数（Shannon—Wiener指数、Simpson指数）、均度指数（Pielou指数）、丰富度指数（Margalef指数、Menhinick指数）对绵阳官司河流域5种不同的人工林进行生物多样性分析,结果表明：经过植被恢复,各林分类型生物多样性都有所提高,同时水土保持效益也明显提高,土壤侵蚀量减少了42％;在5种植被类型中,乔木层中以针阔混交林的生物多样性最高,灌木层以松柏混交林和麻栎林的生物多样性最高,草本层以松柏混交林的生物多样性最高;5种植被类型中,灌木层地上部分生物量以针阔混交林最大为1849．37kg·hm^-2,马尾松纯林最小为747．37kg·hm^-2,其大小顺序为：针阔混交林〉柏木纯林〉栎类林〉松柏混交林〉马尾松纯林;草本层植物地上部分部总生物量大小顺序为：松柏混交林〉柏木纯林〉栎类林〉针阔混交林〉马尾松纯林。     

江西红壤低丘水土流失发生规律和防治对策

综述江西红壤低丘的主要特征、水土流失原因和水土流失规律,提出防治对策和该研究领域中亟待解决的一些问题.     

旅游活动对张家界国家森林公园植被的影响的评价

在张家界国家森林公园的三个景区(金鞭溪、将军岩、天书宝匣),分别选择了四个区域作为样地,本文通过对树木的刻伤数量,植被的种类,数量等的调查,分析了旅游活动对林木及植被的影响。结果表明,公园游道两边的林木受到了游客的严重刻伤,尤以黄石寨景区及金鞭溪景区最为明显。林木受伤程度主要与树种、树皮光滑程度及林木和游道边缘之间的距离有关。本研究以植被影响指数(IVI)来衡量旅游活动对植被的影响。结果显示,在受影响最大的三个景区,IVI 值位于59.4%与87.5%之间,表明其游道两边的植被已受到了严重的影响。针对以上问题,本文提出了关于公园游客管理的一些建议。表5参10。     

Influence of plant communities and soil properties on trace gas fluxes in riparian northern hardwood forests

Wetlands contribute significant amounts of greenhouse gases to the atmosphere, yet little is known about what variables control gas emissions from these ecosystems. There is particular uncertainty about forested riparian wetlands, which have high variation in plant and soil properties due to their location at the interface between land and water. We investigated the fluxes of carbon dioxide (CO₂), nitrous oxide (N₂O), and methane (CH₄) and associated understory vegetation and soil parameters at five northern hardwood riparian sites in the Adirondack Park, NY, USA. Gas fluxes were measured in field chambers 4 times throughout the summer of 2008. CO₂ flux rates ranged from 0.01 to 0.10 g C m⁻² h⁻¹, N₂O fluxes ranged from −0.27 to 0.65 ng N cm⁻² h⁻¹ and CH₄ flux rates ranged from −1.44 to 3.64 mg CH₄ m⁻² d⁻¹. Because we observed both production and consumption of N₂O and CH₄, it was difficult to discern relationships between flux and environmental parameters such as soil moisture and pH. However, there were strong relationships between ecosystem-scale variables and flux. For example, CO₂ and N₂O flux rates were most strongly related to percent plant cover, i.e., the site with the lowest vegetation cover had the lowest CO₂ and highest N₂O emissions. These ecosystem-scale predictive relationships suggest that there may be prospects for scaling information on trace gas fluxes up to landscape and regional scales using information on the distribution of ecosystem or soil types from remote sensing or geographic information system data.     

美国的森林植被模型

从1973年以来, 森林植被模型在美国就被作为森林生长模拟模型来使用, 广泛用于评价林分目前的生长状况和预测不同经营管理措施下林分未来的动态变化。其能够模拟各种不同的森林类型和林分结构, 包括同龄林、异龄林、纯林和混交林, 以及单层混交林和复层混交林等。同时, 森林植被模型能够模拟大多数主要森林树种、森林类型和林分条件在不同森林培育措施(包括疏伐、施肥等)下的变化状况。森林植被模拟体系还能够评价和预测病虫害和火灾等干扰因子对林分状况的影响。目前这个模型已经成为一个高度综合的分析工具体系。     

地被植物在广州城市公园中的应用

该文在对广州城市公园中地被植物的应用情况进行实地调查的基础上,总结出城市公园中常用地被植物的种类有87种,对地被植物在城市公园中与乔木、灌木和草坪植物等不同生活型的植物相配置的方式,以及与山石、水体和园林建筑等造园要素相结合的应用方式进行了分析,并对地被植物在城市公园中应用出现的问题提出自己的看法。