Perimeter-area ratio effects of urbanization intensity on forest characteristics,landscape patterns and their associations in Harbin City,Northeast China

To maximize the ecological services of urban forests, a better understanding of the effects of urbanization on urban forest characteristics, landscape metrics, and their associations is needed for landscape-related regulations in space-limited green infrastructure of metropolitan regions. In this study, Harbin, a typical fast-growing provincial-capital city in Northeast China, is used as a case study. Based on remote sensing images, field surveys, and correlation and variation partitioning analyses, we conclude that landscape characteristics and forest attributes have large variations among different urbanization intensity (UI) regions. Forest patch density (PD), landscape shape index, woody plants species richness, and the Shannon–Wiener index (H′) increased linearly, while stem section area and tree height decreased linearly with the increasing of UIs. UI had a greater influence on tree size and forest community attributes than the forest landscape pattern. Accordingly, any landscape regulation on forest attributes should be implemented according to UIs. In addition, Euclidean nearest neighbor distance(ENN-MN), mean perimeter-area ratio (PARA-MN), fractal dimension index(FRAC-MN), and PD could probably indicate forest attributes the most, e.g., the increase of PARA-MN may be accompanied with taller trees in low and heavy UI regions, but lower woody plants species evenness in low and medium UI regions. More diversified woody plants species, and afforested areas should be advocated in a low UI region, while in a heavy UI region, the conservation of large trees should be implemented. Our results highlight that the implementation of urban forest management should vary according to different urbanization regions to maximize ecological services.

     

Does a More Diversified Revenue Structure Lead to Greater Financial Capacity and Less Vulnerability in Nonprofit Organizations? A Bibliometric and Meta-Analysis

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This article explores how and to what extent revenue diversification and concentration strategies affect financial...     

北京企业空间嵌入天津与河北的探讨

笔者从经济学视角探究省际中心城市经济职能向临近省份嵌入,提出了嵌入势差和嵌入性优势,探讨了双方收益分割。笔者把嵌入过程分为嵌入性优势形成阶段、嵌入阶段、脱嵌阶段和再嵌入阶段四个阶段,通过阶段的划分揭示了发达省份与邻近落后省份之间的一种经济联系。以北京企业嵌入天津和河北为例进行了较为深入的探讨,认为天津与北京的关系处于嵌入过程中的第四个阶段,河北与北京的关系处于嵌入过程的第二个阶段。     

Testing the Only-Child Advantage in Cognitive Development in the Context of China’s One-Child Policy

Population Research and Policy Review - Using data from a recent national survey of approximately 20,000 Chinese middle school students, we tested the difference in cognitive development between...     

大德本《南海志》残卷跋

本文详考元大德本《南海志》成书及其成为残存五卷本的传世经过,并概述此书保存宋元时期广州地区大量史料,参考价值大     

通感表象与意象析论——以儿童艺术通感现象为例

艺术表象是艺术感知和传达中的基本信息元素,它包括记忆表象和想象表象等多种形式,艺术表象在通感发生过程中的转移形式被称为通感表象.它的基本运动形式是,当感官接受外界信息时引起了记忆表象,潜在地发生了想象表象及其转移和联接,在通感过程中表现为通感表象在通感意象作用下的联通和挪移.儿童艺术活动中的表象的生成与转移、抽象过程与成人相比更加清晰,表述更为简洁直白.儿童画是物理表象和情绪表象的混合形式,因而也是记忆表象与想象表象的混合形式,儿童由"表象储存"形式逐渐发展到"表象改编"形式而向"意象"掘进,最后出现"审美意象"而导致通感的产生.     

形象思维在文学作品中的运用——以《廊桥遗梦》为例

本文拟从形象思维这一独特的视角分析其在作品《廊桥遗梦》中的运用。     

农业税改革后我国农村公共产品供给问题及对策分析

农村公共产品的供给不仅影响着农村社会的正常发展,而且影响着我国全面建设小康社会的任务和目标的顺利实现。农业税改革在确保为农民减负增收的同时,也势必会对乡镇基层政府公共产品的供给能力造成影响。要打破城乡“二元结构”,加快农村经济发展;加大中央政府对农村公共产品供给的转移支付;改变乡镇基层政权对农村公共产品“自上而下”的供给模式,充分尊重广大农民意愿;拓展农村公共产品投资渠道;加强对农村公共产品的供给的监督;推进农民自主创业,努力促进农民增收。     

在思想政治理论课中引入案例教学法初探

加强大学生思想政治教育是高校思想政治理论课的主要任务,教学效果将直接关系到大学生思想政治教育的成效。采用案例教学法,对提高思想政治教育的针对性、实效性、吸引力和感染力都具有重要的作用,也是提高思想政治理论课课堂质量的有效方法。