Changes in hillslope hydrology in a perched,shallow soil system due to clearcutting and residual biomass removal

Sustainable fuels legislation and volatility in energy prices have put additional pressures on the forestry sector to intensify the harvesting of biomass for “advanced biofuel” production. To better understand how residual biomass removal after harvest affects forest hydrology in relatively low slope terrain, a Before-After-Control-Impact (BACI) study was conducted in the USDA Forest Service's Marcell Experimental Forest, Minnesota, USA. Hydrological measurements were made from 2010–2013 on a forested hillslope that was divided into three treatment blocks, where one block was harvested and residual biomass removed (Biomass Removed), the second was harvested and residual biomass left (Biomass Left), and the last block was left as an Unharvested Control. The pre-harvest period (2 years) was 2010–11 and post-harvest (2 years) was 2012–13. Water table elevation at the upslope and downslope position, subsurface runoff, and soil moisture were measured between May–November. Mixed effect statistical models were used to compare both the before-after and “control” treatment ratios (ratios between harvested hillslopes and the Unharvested Control hillslope). Subsurface runoff significantly increased (p < .05) at both harvested hillslopes but to a greater degree on the Biomass Left hillslope. Greater subsurface runoff volumes at both harvested hillslopes were driven by substantial increases during fall, with additional significant increases during summer on the Biomass Left hillslope. The hydrological connectivity, inferred from event runoff ratios, increased due to harvesting at both hillslopes but only significantly on the Biomass Left hillslope. The winter harvest minimized soil disturbance, resulting in no change to the effective hydraulic conductivity distribution with depth. Thus, the observed hydrological changes were driven by increased effective precipitation and decreased evapotranspiration, increasing the duration that both harvested hillslopes were hydrologically active. The harvesting of residual biomass appears to lessen hydrological connectivity relative to leaving residual biomass on the hillslope, potentially decreasing downstream hydrological impacts of similar forestry operations.     

楼观台森林公园深层生态旅游开发的模式探讨

提出了深层生态旅游开发的概念,构建了一个“两翼对接”模式。在广泛野外调查的基础上,依据上述理念和开发模型,针对楼观台国家森林公园的景观资源特征,对其深层生态旅游开发进行了系统设计。具体而言,重点突出了自然山水、生物景观和道教文化三方面设计,揭示了三大类60个景物的生态文化主题,设计了相应的开发展示模式和游客生态体验方式。其目的在于,提高森林公园生态文化的展示水平和加深旅游者的生态体验。     

基于芬兰经验的我国森林资源型城市的发展研究--以伊春市为例

资源型城市的可持续发展问题一直是学术界的研究热点,但对于森林资源型城市的研究却不多见。本文概括介绍了芬兰的资源和经济发展情况,系统分析了芬兰这样一个以森林起家的经济发达国家的成功经验;并以伊春为例提出了森林资源型城市经济转型和可持续发展可资借鉴的对策和建议。     

Promoting social justice and conserving montane forest environments: a case study of Nepal's community forestry programme

This paper analyses participatory forest policy and the ways it has influenced the relationships between people as it relates to the forest resource management. This case study was conducted in the middle hills of Nepal, and information was collected through direct observation, individual interviews, group discussion and secondary information analysis. It substantiates a few examples of how the community forestry programme can be used as a means to promote the participation of the women, the poor and dalit (untouchables) in forest resource management, as well as enhancing social justice and improving the forest resources in their locality. However, it also demonstrates that though the community forestry programme has a positive impact, it faces several constraints and challenges. The local Forest User Group is controlled by a few élites making the poor and disadvantaged vulnerable to further marginalization. The results of the case study strongly indicate that community forestry processes must address the political, economic and social needs of the forest users, and also provide a neutral platform on which the poor can present their cases.     

State forestry and spatial scale in the development discourses of post-colonial Tanzania: 1961–1971

At independence, Tanzanian foresters believed that state-led forestry could provide a lasting contribution to the development aspirations of the newly independent country. Yet they were gradually marginalized within Julius Nyerere's project of socio-economic transformation. By exploring the spatial dimensions of competing land use discourses of the time, I hope to offer an interpretation as to how and why forestry's marginalization happened. I argue that at least some of this marginalization was the result of differences inherent in the scale of focus between forestry and the larger, contemporaneous socio-economic and political discourses dominant in the period. At independence, Nyerere positioned development efforts more squarely within the national political institutions of the state and for the nation, writ whole. With its professional and discursive ties to an international forestry order and its spatial biases, Tanzanian foresters were poorly placed to respond or adapt to changes in the political discourse and in the economic conditions of resource extraction. In short, they were unable to adjust to changes in the scale of development praxis in Tanzania. I conclude by suggesting two points. First, that the history of land use and natural resource management choices in post-colonial Tanzania can be better understood through a historical-geographical, or spatialized, theoretical framework. Second, that current historical-geographical theory could be fine tuned through reflection on its utility in describing and explaining land use politics in post-colonial developing contexts.     

'Trees, forests and communities': some historiographical approaches to environmental history on Africa

Focusing on the contested issue of trees and forests, this paper looks at various ways in which historians have explored environmental change and human agency in Africa. It looks in particular at the colonial period and positions the case of the Cape Colony (South Africa) in a broader historiographical context. Colonial silviculture involved both the appropriation of the natural forests and the creation of exotic plantations. These policies generated a mixture of reactions from African communities and had varying effects on the environment. Colonial science and the projects it gave rise to have since been critiqued, contributing to the promotion of community-based forestry schemes that try to incorporate indigenous knowledge and ideas about land use.     

Natural recovery from accelerated forest ditch and stream bank erosion five years after harvesting of plantation forest on Plynlimon,mid‐Wales

Erosion rates surveyed using 230 erosion pins on 24 occasions over eight years (1994–2001) on forested stream banks, tributaries and forest ditches in the 0·89 km² Nant Tanllwyth catchment, part of the Hafren Forest on Plynlimon, mid‐Wales, showed statistically significant increases of up to 40 mm a^?1 in mean erosion rates during the two‐year period in which environmentally sensitive plot‐scale timber harvesting operations took place (1996–97). In the four years following timber harvesting mean erosion rates at all sites recovered to levels that were lower than before the harvesting operations began. This is attributed to increased light levels, following canopy removal, allowing vegetation to colonize exposed banks. There was a statistically significant relationship (p < 0·05) between mean erosion rate in 2000–01 (four years after harvesting) and percentage vegetation cover at erosion monitoring sites in the clearfelled (south tributaries) area though the same relationship did not hold for sites on the mainstream banks or for sites on the north (mature forest) ditch sites. The implications of natural vegetation colonization for management of such streams are discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

基于Web服务的省级林业电子政务信息共享平台的研究

随着信息化建设的深入发展,计算机及网络应用范围不断拓展,应用系统的规模不断扩大,所面临的一个共同问题是如何在原有的建设基础上,进行信息资源的整合,实现信息资源共享。本文以福建省数字林业政务信息共享平台构建为例,在尽可能利用和保护原有投资存量的前提下,针对分布式异构环境中的林业数据和业务应用系统的信息共享要求,提出了基于.NET平台,运用先进的XML&Web Services/MS BizTalk Server2004核心技术的信息交换和共享的整体解决方案及其实现方法。     

激光雷达点云树木建模研究进展与展望

三维树木几何模型是数字城市与数字林业工程的重要组成部分.针对点云树木建模,深入分析了基于广义(泛在)激光雷达点云的树木模型重建方法,提出了聚类思想建模、图论方法建模、先验假设建模、拉普拉斯算子建模与轻量化表达建模5类建模体系,归纳总结了不同建模体系在树冠枝干的细节表达、建模算法性能、树木模型的多层次细节表达、建模体系综...     

‘Let this forest for ever rest’:* tracking protest and identity in Australia’s forests

ABSTRACT

Exploitation of natural resources has long been a flashpoint for contention in Australia. This is clear in the case of forest management, where groups advocating protection have faced off against state and industry actors. The move towards multifunctionalism that recognises different values in the management of natural resources has led to a search for alternative solutions. In the case of forestry, introduction of Regional Forest Agreements (RFA) in the 1990s sought to devolve responsibility to the States, while striking a balance between economic and environmental considerations. The aim of this paper is to identify how forest activism has developed since the RFA process began and its significance in relation to changes in land use. The paper draws on a protest event catalogue of forest-related events over the 1997–2017 period to identify the intensity, tactics and location of such actions. The findings suggest that state action has reduced the intensity of contention, in line with changes in resource management practices. However, they also point to the importance of identity and its link to the social construction of resources in determining the ability of actors to de-escalate and find solutions.