广东森林火灾碳排放及应对气候变化策略

森林是生态系统中重要的碳库。森林火灾将森林中存储的碳重新释放至大气中,对全球气候变化产生重大影响。文章介绍了国内外森林火灾碳排放及其计量技术,对广东森林火灾碳排放进行估测,评价了森林火灾对气候变化的影响,并指出广东应对气候变化的森林防火对策。     

中国森林碳汇交易立法问题研究

进行森林碳汇交易立法契合中国温室气体减排的现实需要,符合森林碳汇交易的实践需求,可有效弥补当前森林生态效益补偿之不足。京都规则为国内森林碳汇交易立法提供了有益借鉴。中国森林碳汇交易多由行政规章和政策性文件规范,适用于实践力有不逮。故应加强相关立法,明确规定森林碳汇交易的法律地位、实施条件与保险规则。《森林法》修改应当对森林碳汇交易进行原则规定,再由下位法予以配套。     

低蛋白日粮在养猪生产中的应用进展

低蛋白饲料具有降低饲料成本,提高猪只蛋白消化利用率和改善猪只肠道微生物菌群结构等作用,已被广泛应用于养猪生产中。文章综述了低蛋白日粮对养猪产业、猪只生产性能、猪肉品质和猪只肠道微生物的影响。阐述了低蛋白日粮在养猪生产中的饲养效果,旨在为低蛋白日粮在养猪生产中的应用提供科学的指导。     

Methane mitigation in flooded Louisiana rice fields

Summary A field experiment was conducted to determine whether selected nitrification inhibitors (encapsulated calcium carbide and dicyandiamide) and SO _inf4 ^sup-2 -containing compounds [(NH₄)₂SO₄ and Na₂SO₄] had mitigating effects on CH₄ emissions from flooded rice. Microplots were established within a rice bay drill-seeded with the Texmont rice cultivar and CH₄ fluxes were measured over the main rice cropping season. Methane emissions over the 77-day sampling period were approximately 230, 240, 260, 290, 310, and 360 kg CH₄ ha^-1 from the calcium carbide, Na₂SO₄-rate II, Na₂SO₄-rate I, (NH₄)₂SO₄, dicyandiamide, and urea (control) treatments, respectively. Reductions in CH₄ evolution, compared to the control, ranged from 14 to 35%, depending on treatment. The selected inhibitors and SO _inf4 ^sup-2 -containing compounds appear to be effective in reducing the CH₄ emitted from flooded rice fields.     

土地复垦视角的低排放控制研究

随着经济社会的高速发展,生态环境逐步恶化,土地资源正面临严峻挑战,为实现土地资源持续利用和土地生态的健康发展,新一轮土地整治工作正全面展开.在此背景下,该研究结合国家新颁布的《土地复垦条例》以及多年来土地复垦工作所取得的成效和存在的问题,重点研究当前土地复垦中低排放控制的关键技术与方法.结果表明:土地复垦作为土地资源可持续发展的必要保障措施,目前缺乏相关低排放控制研究;现行土地复垦模式在当前社会经济发展的新形势、新要求下,其传统的复垦模式具有一定的局限性、缺乏新理念;通过文献综述法,结合土地复垦的内容与特征,总结归纳了边坡治理低排放、自然灾害损毁土地低排放、矿区固体废弃物和水污染低排放、土壤与和植被固碳减排等关键技术;低碳排放与土地复垦息息相关,做好土地复垦与低碳排放工作,对我国碳排放控制目标具有积极贡献.     

IMPROVING NITROGEN SAFETY IN CHINA: NITROGEN FLOWS,POLLUTION AND CONTROL

● It is necessary to address the N flows and their impacts on environment in China for sustainable N management. ● Barriers include better understanding of N cycle mechanisms and improving low cost abatement technologies are needed to overcome. ● Integrated measures and policies are crucial for the abatement of adverse impacts of N. The impacts of nitrogen on environmental quality, greenhouse gas balances, ecosystem and biodiversity in China are of great concern given the magnitude of demand for food and energy. Comprehensive summaries of historic N flows and their critical threats and sustainable management are urgently needed. This paper initially reviews the historical trends of N flows in China and identifies the critical threats of N loss. Subsequently, it describes some recent success stories of N management, and finally indicates barriers to N pollution control. This review highlights three key points. Firstly, a steady increase of N input in China has led to a series of environmental problems via leaching and runoff, ammonia emissions and denitrification. Secondly, although great efforts to improve N management and N safety in China, further quantifications of N flows and analysis of their underlying mechanisms are needed to improve the understanding of the N cycle and pollution control. Finally, it proposes that the best available technologies combined with regulatory plans, laws, projects and policies should be implemented to overcome current barriers in N control and achieve a balance between the sustainable use of N resources and environmental conservation in China.     

黑龙江农垦种养业生产系统温室气体排放与土壤固碳的核算

为探究区域种养业减排增效潜力,采用最新温室气体清单指南,对区域种养业生产系统温室气体排放与土壤固碳的途径和计算方法进行梳理,以黑龙江农垦种养业生产系统为研究对象,计算分析与评价该系统2009—2018年温室气体排放量与土壤固碳量。结果表明:1)在温室气体排放方面,黑龙江农垦种养业生产系统的温室气体排放量呈现“增长—下降后平稳”的趋势,2018年为2.48×1010 kg,秸秆焚烧碳排放、主要物资碳排放、稻田CH4排放为主要来源,约占排放总量的84.87%。2)在土壤固碳方面,玉米和大豆的秸秆、根系输入引起的土壤有机碳的累积变化量分别为2.15×109和1.53×108 kg,而奶牛、肉牛、蛋鸡、肉鸡和生猪有机肥输入引起的土壤有机碳的累计变化量分别为-1.43×108、-5.46×107、-2.67×106、2.26×106和-9.68×107 kg。3)近年来黑龙江农垦种养业生产系统温室气体净排放量有所增长、经济效益有所下降。基于研究结果,提出如下建议:1)加大农作物秸秆和畜禽粪便资源综合利用,建立第三方集中处理中心,减少秸秆焚烧和畜禽粪便未利用;2)确定适宜的有机物料输入种类与量,促进土壤碳固定;3)开展农机具使用效率研究。     

Potential CO2 emissions mitigation through forest prescribed burning: A case study in Patagonia, Argentina

Wildland fire is a natural force that has shaped most vegetation types of the world. However, its inappropriate management during the last century has led to more frequent and catastrophic fires. Wildland fires are also recognized as one of the sources of CO₂ and other greenhouse gases (GHG) that influence global climate change. As one of the techniques used to reduce the risk of destructive wildfires, prescribed burning has the potential of mitigating carbon emissions, and effectively contributes to the efforts proposed as part of the Clean Development Mechanism within the Kyoto protocol. In order to apply this concept to a real case, a simulation study was conducted in pine afforestation in the Andean region of Patagonia, Argentina, with the objective of evaluating the potential of prescribed burning for reducing GHG emissions. The scenario was established for a ten year period, in which simulated prescribed burning was compared to the traditional management scheme, which included the probability of annual average of wildfire occurrence based on available wildfire statistics. The two contrasting scenarios were: (1) managed afforestation, affected by the annual average rate of wildfires occurred in the same type of afforestation in the region, without prescribed burning, and (2) same as (1) but with the application of simulated prescribed burning. In order to estimate carbon stocks, and CO₂ removals and emissions, we followed the guidelines given for GHG inventories on the Agriculture, Forestry and Other Land Uses (AFOLU) sector of the International Panel on Climate Change (IPCC), while the terminology used was the established by IPCC (2003). Data of afforested area, thinnings, and biomass growth were taken from previous surveys in the study area. Downed dead wood and litter (forest fuel load, FFL) was estimated adjusting equations fitted to those fuels, based on field data. Results show that comparing the two scenarios, prescribed burning reduced CO₂ emissions by 44% compared to the situation without prescribed burning. The prescribed burning scenario represented about 12% of the total emissions (prescribed burning plus wildfires). Furthermore, avoided wildfires by simulated prescribed burning allowed an additional 78% GHG emissions mitigation due to extra biomass growth. Simulated prescribed burning in commercial afforestation of Patagonia appears to be an effective management practice not only to prevent wildfires, but also an efficient tool to mitigate GHG emissions. However, more studies in different scenarios would be needed to generalize these benefits to other ecosystems.     

Implications of fires on carbon budgets in Andean cloud montane forest: The importance of peat soils and tree resprouting

Fire in tropical montane cloud forests (TMCFs) is not as rare as once believed. Andean TMCFs sit immediately below highly flammable, high-altitude grasslands (Puna/Páramo) that suffer from recurrent anthropogenic fire. This treeline is a zone of climatic tension where substantial future warming is likely to force upward tree migrations, while increased fire presence and fire impacts are likely to force it downwards. TMCFs contain large carbon stocks in their peat soils and their loss through fire is a currently unaccounted for regional source of CO₂. This study, conducted in the southern Peruvian Andes (>2800 m), documents differences in live tree biomass, fine root biomass, fallen and standing dead wood, and soil organic carbon in 4 paired-sample plots (burned versus control) following the severe ground fires that occurred during the 2005 Andean drought. Peat soils contributed the most to biomass burning emissions, with lower values corresponding to an 89% mean stock difference compared to the controls (mean ± SE) (54.1 ± 22.3 vs. 5.8 ± 5.3 MgC ha⁻¹). Contrastingly, carbon stocks from live standing trees differed by a non-significant 37% lower value in the burned plots compared to the controls, largely compensated by vigorous resprouting (45.5 ± 17.4 vs. 69.2 ± 13.4 MgC ha⁻¹). Both standing dead trees and fallen dead wood were significantly higher in the burned plots with a three-fold difference from the controls: dead Trees 45.2 ± 9.4 vs. 16.4 ± 4.4 MgC ha⁻¹, and ca. a 2 fold difference for the fallen dead wood: 11.2 ± 5 vs. 6.7 ± 3.2 MgC ha⁻¹ for the burned plots versus their controls. A preliminary estimate of the regional contribution of biomass burning emissions from Andean TMCFs for the period 2000-2008, resulted in mean carbon emission rates of 1.3 TgC yr⁻¹ (max-min: 1.8-0.8 TgC yr⁻¹). This value is in the same order of magnitude than South American annual fire emissions (300 TgC yr⁻¹) suggesting the need for further research on Andean forest fires. On-going projects on the region are working on the promotion of landowner participation in TMCFs conservation through REDD+ mechanism. The heart of the proposed initiative is reforestation of degraded lands with green fire breaks enriched with economically valuable Andean plant species. The cultivation of these species may contribute to reduce deforestation pressure on the Amazonian cloud forest by providing an alternative income to local communities, at the same time that they prevent the spread of fire into Manu National Park and adjacent community-held forests, protecting forest and reducing CO₂ emissions.     

商用空气源热泵热水器的效益分析

介绍了空气源热泵热水器的工作原理及特点,并以某大学的澡堂热水机组使用情况为例,对燃煤锅炉热水器和商用型空气源热泵热水器的经济效益及社会效益进行了对比分析,结果表明:空气源热泵热水器具有较大的优越性。