Variability of Fire Behavior, Fire Effects, and Emissions in Scotch Pine Forests of Central Siberia

As part of the Russian FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project, replicated 4-ha experimental fires were conducted on a dry Scotch pine (Pinus sylvestris)/lichen (Cladonia sp.)/feathermoss (Pleurozeum schreberi) forest site in central Siberia. Observations from the initial seven surface fires (2000-2001) ignited under a range of burning conditions quantified the different fuel consumption and fire behavior characteristics (e.g., rate of spread, fireline intensity, etc.) possible in this particular forest fuel type. Experimental results and dendrochronological study of local fire history both support the dominance of local fire regimes by low to moderate-intensity surface fires. Carbon released by the experimental fires ranged from 4.8 to 15.4 t C ha^{− 1} depending on fuel conditions and fire severity. Preliminary emission data show a strong correlation between carbon dioxide (CO₂) and carbon monoxide (CO) emissions, which should facilitate accurate estimates of fire impacts on atmospheric chemistry. Carbon concentration in smoke samples was related to fire severity. The short landscape-scale fire-return interval (50 years), combined with typically low fire severity, in pine ecosystems of central Siberia is often associated with low tree mortality and relatively rapid buildup of litter and understory fuels after a fire.     

气候变化对珙桐分布的潜在影响

分析气候变化对植物分布的影响,对气候变化影响下的生物多样性保护具有重要意义. 利用分类和回归树 (Classification and Regression Tree,CART)生态位模型,设定A1,A2,B1和B2 4种气候变化情景,模拟分析了气候变化对珙桐(Davidia involucrata Baill)分布的影响. 结果表明:随气候变化,珙桐目前适宜分布范围将减小,但新适宜及总适宜分布范围将扩大;珙桐适宜分布范围在模拟时段呈缩小趋势,在A1情景下减幅最大,B1情景下减幅最小. 气候变化后,由于珙桐目前适宜分布范围的东部、南部、北部、东北部和东南部地区缩小,而新适宜分布范围将主要向我国西部及西南部地区扩展,因此,目前适宜分布范围将被破碎化. 气温变化对珙桐分布范围的影响大于降水量的影响.      

提高环境意识转变公众行为应对气候变化

全球气候变化是人类面临的最为严峻的挑战之一,如何有效地提高公众环境意识,发挥公众在应对气候变化中的积极作用,是目前面临的重要课题。本文在研究环境意识、环境宣传教育的国内外理论基础上,结合成功的公众气候变化宣传教育典型案例,探讨提高公众意识,切实参与应对气候变化的机制和途径。     

Impacts of Climate Change on the Distribution of Larix Spp. and Pinus Sylvestris and Their Climatypes in Siberia

Inter- and intraspecific effects of climate change were assessed for the dominant conifers of Siberia (60–140^∘E and 48–75^∘N): Larix spp. (L. sibirica, L. dahurica, and L. sukaczewii) and Pinus sylvestris . The approach employed a tri-variate (degree-days above 5 ^∘C, degree-days below 0 ^∘C, and a moisture index) estimate of the climatic envelope within which exists the actual ecological distribution of a species and their constituent climatypes (genotypes physiologically attuned to similar environments). Limits of the actual ecological distribution were approximated by reducing the climatic envelope according to effects of permafrost and interspecific competition. Climatypes were mapped within the climatic envelope according to the climatic interval that must separate populations for reasonable assurance of genetic differentiation. This interval was calculated from response functions that related 13-year growth and survival of a species to the difference in climate between the provenance of a climatype and the climate of numerous test sites distributed across Russia. Mapping species' distributions and their climatypes was done for the contemporary climate and for future climates predicted by the HadCM3GGa1 scenario of Hadley Centre. The results showed that if the forests of the future are to reflect the adaptedness of today, the distribution of species will shift and genotypes within species will be redistributed. Some contemporary climatypes are projected to disappear from Siberia while others common elsewhere would evolve. To mitigate these effects, climatypes should be transferred today to the expected future location of their climatic optima, a distance that is likely to approach 700–1200 km for these species.     

气温和土壤湿度变化对3种典型荒漠植物种子发芽的影响

植物种子发芽对气温和土壤湿度变化的响应是气候变化对荒漠生态系统影响的关键. 为了分析荒漠植物种子发芽对气温和土壤湿度变化的响应趋势,选择典型荒漠植物沙拐枣(Calligonum mongolica)、泡泡刺(Nitraria sphaerocarpa)和麻黄(Ephedra przewalskii),在人工气候箱中分析在3种土壤湿度(3%,5%和15%),2种气温(16 ℃/22 ℃ 和21 ℃/27 ℃)和浸种(12 h)与不浸种处理下种子的发芽趋势. 结果显示:沙拐枣和泡泡刺种子的发芽率随土壤湿度的增加而增加,浸种下随气温的升高其发芽率增幅比不浸种下大;不浸种下气温升高麻黄种子发芽率增幅比不浸种下大,浸种下土壤湿度为3%时气温升高其发芽率增幅比土壤湿度为5%和15%时大(P<0.05). 3种植物种子发芽指数随气温的升高和土壤湿度的增加而增加,不浸种下气温升高沙拐枣和泡泡刺种子的发芽指数显著增加,浸种下其发芽指数增幅不大;不浸种下气温升高麻黄种子发芽指数增幅较小,浸种下其发芽指数增幅较大. 3种植物种子均在培养初期发芽速率增加较快. 荒漠植物种子发芽受气温和土壤湿度的共同影响,不同植物种子发芽对这些因素的变化有不同的响应.      

气候变化对植物及植被分布的影响研究进展

准确预测气候变化对植物及植被分布的影响趋势对于科学认识气候变化对生物多样性的影响和对策制定具有重要的意义。近年来,气候变化对植物及植被分布影响研究在我国广泛展开。文章对这些研究所采用的气候情景、预测方法和气候变化等对植物及植被分布的影响趋势进行了总结分析,对存在的问题进行了讨论,对未来的趋势提出了若干展望。总体上,目前所用气候情景比较单一、不同预测方法比较研究不够,对土壤和生物因素考虑不充分、涉及植物种类太少。气候变化将使一些植物分布范围减少、甚至消失,而使另一些植物分布范围则会扩大。未来研究应加强气候情景改进和不同方法的比较研究,充分考虑土壤和生物等因子、加强预测方法检验,同时开展植物物种多样性和丰富度对气候变化响应方面的研究。     

Impact of Climate Change on Maize Yield in Central and Northern Greece: A Simulation Study with Ceres-Maize

The potential impacts of climate change on the phenology and yield of two maize varieties in Greece were studied. Three sites representing the central and northern agricultural regions were selected: Karditsa, Naoussa and Xanthi. The CERES-Maize model, embedded in the Decision Support System for Agrotechnology Transfer (DSSAT 3.0), was used for the crop simulations, with current and possible future management practices. Equilibrium doubled CO₂ climate change scenarios were derived from the GISS, GFDL, and UKMO general circulation models (GCMs); a transient scenario was developed from the GISS GCM transient run A. These scenarios predict consistent increases in air temperature, small increases in solar radiation and precipitation changes that vary considerably over the study regions in Greece. Physiological effects of CO₂ on crop growth and yield were simulated. Under present management practices, the climate change scenarios generally resulted in decreases in maize yield due to reduced duration of the growing period at all sites. Adaptation analyses showed that mitigation of climate change effects may be achieved through earlier sowing dates and the use of new maize varieties. Varieties with higher kernel-filling rates, currently restricted to the central regions, could be extended to the northern regions of Greece. In the central regions, new maize varieties with longer grain-filling periods might be needed.     

Arctic Residents' Observations and Human Impact Assessments in Understanding Environmental Changes in Boreal Forests: Russian Experience and Circumpolar Perspectives

Three methods of gathering local and traditional knowledge of Indigenous Peoples were used to assess environmental changes and human impacts in Russian boreal forest communities: structured interviews, followed by an unstructured interview, and an education/training workshop. The most important environment changes reported by Indigenous Peoples included the disappearance of animals and plants, climate changes, a decrease in forest and shrub area, and human impacts such as poaching, forests fires, industrial logging, clearing of forests for firewood, and water pollution by industrial wastes and discharges. We propose establishment of the Boreal Residents' Network for Socio-environment Assessments and Education for Sustainable Development to acquire local and traditional knowledge as a supplement to scientific monitoring. The proposed approach would involve permanent inhabitants living in a broad range of boreal forests to gather local and traditional knowledge and assessments. This could lead to a meta-database to share with international networks.     

考洲洋水环境质量现状及受潮汐影响变化分析

文章应用单因子标准指数法、算术均值多因子指数法和营养状态指数法相结合的方法对当前考洲洋海域海水质量状况进行了评价,并依据考洲洋在潮汐涨、落情况下海水质量的变化,定量分析了考洲洋潮汐对其海水水质的影响。结果表明:磷酸盐、无机氮、石油类是影响考洲洋海域环境质量的主要因子,考洲洋内部海域均处于富营养化状态,总体水质状况为良好以下,潮水的涌入能改善考洲洋的水质状况,涨潮时期各航次的算术均值多因子指数之和比退潮时期平均降低了13.92%。且潮汐的变化对主要污染因子的影响顺序为:无机氮>磷酸盐>石油类,最后提出了考洲洋污染防治的对策和建议。