Not erroneous but cautious conclusions about the potential effect of climate change on the geographical distribution of insect pest species in the Swedish boreal forest. Response to Björklund et al. (2015)

We argue that the conclusions drawn from the paper “The potential effect of climate change on the geographical distribution of insect pest species in the Swedish boreal forest”, published in the Scandinavian Journal of Forest Research were not erroneous as stated by a letter published in the same journal by Björklund et al. (2015. Erroneous conclusions about current geographical distribution and future expansion of forest insects in Northern Sweden: Comments on Hof and Svahlin (2015). Scand. J. Forest Res)”, but cautious. We regret possible underestimations caused by lack of occurrence records for some species for some areas. However, basing predictions of the impact of future climate change on the distribution of species on current range maps likely leads to grave overestimations of future range predictions since current range maps assume species are homogenously distributed throughout the landscape, which is often not the case. We argue that underestimating the distribution range of pest species rather than overestimating their distribution pinpoints areas that may need extra attention in future better, and therefore chose to be cautious rather than bold. We further like to stress that one should always be aware of possible insect outbreaks throughout the region, not only because predictions may underestimate the future distribution of species but also since the location and likelihood of insect pest outbreaks is not only determined by climatic factors.     

Erroneous conclusions about current geographical distribution and future expansion of forest insects in Northern Sweden: comments on Hof and Svahlin (2015)

We question the validity of the results and the conclusions from a study entitled “The potential effect of climate change on the geographical distribution of insect pest species in the Swedish boreal forest” that was recently published in Scandinavian Journal of Forest Research. The main problem is that for several of the species the current geographical distributions presented in the paper (based on modeling of a limited set of occurrence data) are vastly underestimated compared with distribution maps in standard reference literature and other available occurrence data. As a consequence of that the predicted major future range expansions of these important pest species are also erroneous.     

Comparison of beta and weibull functions for modelling basal area diameter distribution in stands of pinus sylvestris and picea abies

The purpose of this study was to compare beta and Weibull distributions in describing basal area diameter distributions in stands dominated by Scots pine and Norway spruce. The material of the study consisted of 535 stands located in eastern Finland. Parameters for both two‐ and three‐parameter approaches of the Weibull distribution were estimated using the method of maximum likelihood. Models for these parameters were derived using regression analysis. For the beta distribution, regression models were formed for the minimum, maximum and standard deviation of diameters within individual stands. These models were used when the exponents of the beta distribution were calculated analytically. Also, some parameter models for beta and Weibull distributions from previous studies were compared with the measured diameter distributions. The distributions obtained were compared using diameter sums and an estimate of the proportion of sawtimber. The results did not reveal any major differences between the suitability of the beta and two‐parameter Weibull distributions. There are appropriate models available for both of the distributions and the more similar the original data is to the data of an application, the better are the results. The two‐parameter approach of the Weibull distribution gave better results than the three‐parameter approach. The poorest results for all the predicted distributions were obtained at the extremes of the distributions.     

The impacts of climate change on potential natural vegetation distribution

Change in potential natural vegetation (PNV) distribution associated with climate change due to the doubling atmospheric carbon dioxide (2×CO₂) was estimated with a global natural vegetation mapping system based on the modified Kira scheme to the globe and the continents. With an input of widely-distributed global climate data, the system interpolates data onto a 1° latitude by 1° longitude grid over the globe, generates estimates of vegetation type, and produces a composite PNV map. The input climate data corresponding to the 1×CO₂ and 2×CO₂ consists of observations prior to AD 1958 at 2,001 weather stations worldwide and the 2×CO₂ simulation output from the Japan Meteorological Research Institue's General Circulation Model, respectively. As a result of the simulated global warming, the vegetation zones expanded mostly from the tropics toward the poles. PNV area changed by 6.98 billion (G) ha of the total land area (15.04 Gha) and potential forest area corresponding to the closed forest and open forest (woodland) reached 9.74 Gha with the increase of 1.29 Gha. The potential forest area in Europe had obvious advantages to the climate change accompanied with the increase of actual forest area. Although the actual forest area has decreased in North America and Asia, the potential forest area in these continents also benefitted from the climate change. In the end, the remaining continents tended to bear the brunt of the climate change.     

The effect of density after precommercial thinning on volume and structure in Pinus Sylvestris and Picea Abies stands

The interaction between stand density and dominant height and the development of volume, mean diameter, mortality and distribution of volume during a period from precommercial thinning to first commercial thinning was studied on permanent plots in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) stands in Sweden. The reciprocal equation of the yield density effect was used to level the volume yield. Higher density after precommercial thinning resulted in higher yield and smaller mean diameter. The mortality up to first thinning was low, but is also dependent on density after precommercial thinning. The positive skewness of the volume distribution was higher in denser stands.     

Expansion potential of invasive tree plants in ecoregions under climate change scenarios: an assessment of 54 species at a global scale

Climate change may increase expansion risk of invasive tree plants (ITPs) worldwide. Ecoregions are the power conservation tool for the management of ITPs. However, few studies have investigated the relationship between ITP expansion and ecoregions at the global scale under climate change scenarios. Here, we provided a method to evaluate the expansion potential of 54 representative ITPs in ecoregions specifically under influences of the changing climate at the global scale. We found that climate change due to increasing greenhouse gas (GHG) concentration plays a positive role on the expansion of ITPs. We determined two of the most important ecoregion hotspots of ITP expansion potential, such as New Zealand and South Africa. In addition, ITPs were likely to have a large potential to expand in ecoregions of five different biomes, like temperate broadleaf and mixed forests. The potential expansion of ITPs would increase obviously in ecoregions of Boreal Forests/Taiga and Tundra. More importantly, the ecoregions of high elevation belonging to Tropical and Subtropical Coniferous Forests were expected to experience the higher expansion risk in the low GHG concentration scenario. Given our estimates of ITP expansion for ecoregions, management for the prevention and control for ITPs is urgent at the global scale.     

Extent,distribution and origin of non-native forest tree species in Europe

ABSTRACT

The management of non-native tree species in European forests has a long history, but the information on the current number and geographic distribution of these species in European forests is incomplete and scattered across various datasets. This study aims to perform an inventory of the most frequent non-native tree species growing in European forests and analyse their current extent, geographic distribution and geographic origin. Our results show that at least 150 non-native tree species are currently growing in European forests and provenance trials. The genera represented by largest number of species are Eucalyptus, Pinus, Acacia and Abies. Species growing at the largest areas are Robinia pseudoacacia (2.44 million ha), Eucalyptus globulus (1.46 million ha), Picea sitchensis (1.16 million ha) and Pseudotsuga menziesii (0.83 million ha). In total, non-native tree species in Europe are found in an area of approximately 8.54 million ha, or 4.0% of the European forest area, and the five most abundant species account for up to 77% of this area. The largest number of these 150 species were introduced from North America (71), followed by Asia (45) and Australia (20). North American species occupy by far the largest area.     

我国林业应对气候变化问题的基本定位及政策建议

气候变化所带来的不仅是全球生态环境的变化,也是国际政治经济利益格局的重大调整,必须予以高度重视。气候变化与我国林业的关系,主要表现在两个方面：一方面,我国植树造林的发展,对减缓全球变暖做出了重大贡献;另一方面,气候变化对我国森林的格局产生重大影响,并进而威胁到国家生态安全。在应对气候变化的国家战略中,明确林业的基本定位,对于我国在气候变化国际谈判中争取主动,并及早采取预防措施减轻未来由气候变化可能带来的灾害,有着双重的积极作用。     

历史时期气候变化对西北地区竹林分布的影响

历史时期中国气候经历了冷暖相间的几度波动变化,对竹林的生长也发生了很大影响,西北地区竹林的分布范围也随气候的波动发生了变迁。竹林分布总体上来看是逐渐南移,汉唐时期其作为重要的经济作物,元代以后其经济作物的地位已变得不十分重要。本文分仰韶温暖、先秦、秦汉魏晋六朝、隋唐五代、宋元、明清等时期,论述了气候变化对西北地区竹林分布的影响。     

A Study on the Impacts of Climate Change on the Distribution of Pinus tabulaeformis in China

A special interpolation program GREEN has been developed to determine the climatic parameters for the distribution region of Chinese pine (Pinus tabulaeformis Carr.) based on the researches on the distribution of the tree species. The central region, which is the most suitable distribution region, and potential distribution region of the species under current climatic conditions were mapped using a Geographic Information System IDRISI. According to the averaged predictions by 5 GCMs for 2030, a projection was made for the future distribution of the pine. The results show that the potential distribution area of Chinese pine will have a small northward shift, though not significantly. The east part of the northern boundary will move northwards by 1.4 degree, while the southern boundary will move northwards about 0.2 degree in latitude. The east and west edges will both move towards the distribution center. The potential distribution region will shrink by 9.4% compared with the current area. The species wi     

Future impacts of climate change on forest fire danger in northeastern China

Climate warming has a rapid and far-reaching impact on forest fire management in the boreal forests of China. Regional climate model outputs and the Canadian Forest Fire Weather Index (FWI) Sys- tem were used to analyze changes to fire danger and the fire season for future periods under IPCC Special Report on Emission Scenarios (SRES) A2 and B2, and the data will guide future fire management planning. We used regional climate in China (1961 1990) as our validation data, and the period (1991-2100) was modeled under SRES A2 and B2 through the weather simulated by the regional climate model system (PRECIS). Meteorological data and fire danger were interpolated to 1 km 2 by using ANUSPLIN software. The average FWI value for future spring fire sea- sons under Scenarios A2 and B2 shows an increase over most of the region. Compared with the baseline, FWI averages of spring fire season will increase by 0.40, 0.26 and 1.32 under Scenario A2, and increase by 0.60, 1.54 and 2.56 under Scenario B2 in 2020s, 2050s and 2080s, respectively. FWI averages of autumn fire season also show an increase over most of the region. FWI values increase more for Scenario B2 than for Scenario A2 in the same periods, particularly during the 2050s and 2080s. Average future FWI values will increase under both scenarios for autumn fire season. The potential burned areas are expected to increase by 10% and 18% in spring for 2080s under Scenario A2 and B2, respectively. Fire season will be prolonged by 21 and 26 days under ScenariosA2 and B2 in 2080s respectively.     

STUDY ON THE EFFECT OF CLIMATE CHANGE ON FOREST FIRE IN HEILONGJIANG PROVINCE

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近15年来气候变化对中国经济的直接影响

以国家权威部门发布的统计资料为基础数据,分析气候变化对中国经济的影响,结果表明:近15年来气候变化对中国经济的影响在加剧。1991~2005年期间与气候变化相关的自然灾害造成的直接经济损失在932亿~3 570亿元之间,呈明显上升趋势;所占GDP的比重为5.70%~1.31%,呈下降趋势。在此期间,干旱、农作物病虫害、草地病虫害、风暴潮、森林火灾的直接经济损失呈现上升趋势;洪涝灾害和台风上升趋势不明显;森林病虫害和草地火灾呈下降趋势。2000年以来自然灾害的直接经济损失一直稳定在相当于GDP 1.08%~2.05%的水平,气候变化对国民经济存在不可忽视的负面影响。     

Signals of summer drought in crown condition data from the German Level I network

Crown transparency estimates of Scots pine, Norway spruce, common beech, pedunculate and sessile oak, annually surveyed between 1990 and 2004 within a grid over Germany, provide a suitable response variable to study drought effects on forest trees. Major climatic factors, available on a monthly basis as plot-specifically interpolated values and parameters of site and stand conditions, biotic and other relevant factors were used as predictors in different cross- and length-sectional, and longitudinal models. Stand age is a considerable and most constant driver of crown transparency in all species. Pine, spruce and beech responded—mainly with a delay of 1 year—with some foliar loss in areas where there was a surplus of temperature after the generally hot and dry summer of 2003. Parallel time-series analyses delivered species-specific geographic large-scale patterns with delayed or recent precipitation deficits or temperature surpluses. Even if beech is partly responding in current years with leaf loss towards precipitation surpluses, defoliation is especially high 1 year after hot summers, partly a result of high seed sets after such summers. Crown condition of oak responds in dry and warm areas according to the drought stress hypothesis, however, in cool and wet mountainous ranges oak responds after wet summers with higher defoliation. Longitudinal approaches revealed for all 4-tree species significant relationships between crown condition and deviations from the long-term means of temperature, precipitation but also global radiation and wind speed. Results do not always match the drought stress hypothesis, however, this is not to expect considering the heterogeneous site, stand and climatic conditions across Germany. Complex interactions of climatic and biotic factors also impede simple relationships. Soil-related clusters reveal higher sensitivity of spruce and beech towards climatic drought factors on more acid soils with thin humus layers. Also clusters constructed from plot-specific courses of defoliation reveal groups with rather closer relationships like a group of pine plots in the Oberpfalz, which seems to be especially sensitive to summer drought.     

An integrated spatial assessment of the investment potential of three species in southern Ontario, Canada inclusive of carbon benefits

This study explores the economic feasibility of several long-rotation afforestation scenarios for southern Ontario, Canada. Three species, red pine (Pinus resinosa Ait.), Norway spruce (Picea abies L.) and black walnut (Juglans nigra L.) are examined. We integrate growth and yield models, site suitability maps, and several management scenarios to investigate the investment attractiveness of these species inclusive and exclusive of carbon sequestration values. We report net present values (NPV), internal rates of return (IRR) and two break-even price metrics. For wood value only scenarios the IRRs range from 4.3 to 4.6% for red pine and 3.4–3.6% for Norway spruce (for the most attractive 10,000 ha, in a single rotation scenario). Black walnut had rates of return 3.5–3.7% for the most attractive 10,000 ha area. Adding carbon valued at Cdn $3.4 per metric ton CO_2 − e (roughly 2005 prices in the Chicago Climate Exchange) increases rates of return by about 0.6% for red pine and Norway spruce and 0.4% for black walnut scenarios. Perhaps surprisingly these returns are comparable and better than 20-year rotation hybrid poplar plantations. To achieve a 6% real rate of return break-even carbon prices were $10.7/t CO_2 − e for red pine, $12.6/t CO_2 − e for Norway spruce and $17.2/t CO_2 − e for black walnut (again for the “best” 10,000 ha). Although somewhat unremarkable, the results suggest that these longer-rotation species may be a better investment than perhaps previously expected if landowners have the appropriate site conditions.     

Multiple-use forest management in consideration of climate change and the interests of stakeholder groups

In this study, the overall utility of forest management alternatives at the forest management unit level is evaluated with regard to multi-purpose and multi-user settings by a multi-criteria analysis (MCA) method. The MCA is based on an additive utility model. The relative importance of partial objectives of forest management (carbon sequestration, ground water recharge, biodiversity, and timber production) is defined in cooperation with stakeholders. The forest growth model 4C (Forest Ecosystems in a Changing Environment) is used to simulate the impact of six forest management strategies and climate on forest functions. Two climate change scenarios represent uncertainties with regard to future climatic conditions. The study is based on actual forest conditions in the Kleinsee management unit in east Germany, which is dominated by Scots pine (Pinus sylvestris L.) and oak (Quercus robur L. and Quercus petraea Liebl.) stands. First, there is an analysis of the impact of climate and forest management on forest functions. Climate change increases carbon sequestration and income from timber production due to increased stand productivity. Secondly, the overall utility of the management strategies is compared under the priority settings of different stakeholder groups. From an ecological perspective, a conservation strategy would be preferable under all climate scenarios, but the business as usual management would also fit the expectations under the current climate due to high biodiversity and carbon sequestration in the forest ecosystem. In contrast, a forest manager in public-owned forests or a private forest owner would prefer a management strategy with an intermediate thinning intensity and a high share of pine stands to enhance income from timber production while maintaining the other forest functions.     

Extreme events and climate change: the post-disaster dynamics of forest fires and forest storms in Sweden

How are extreme events understood in the forest sector? What are the implications of forest professionals' understandings and evaluations of extreme events? These questions are central to this study, which analyses the handling of the largest forest storm and the largest forest fire in modern Swedish history. The theoretical approach is that of risk governance in practice, which stresses that understanding the framings, practices and strategies used by members of professional organizations is pivotal for how disasters are managed. Two interview studies have been conducted with forest professionals involved in the two cases. The analysis shows that there were fundamentally different understandings of the two events and their implications for forestry practice. The storm was seen as an unavoidable natural disaster, but the consequences of future storms were considered possible to mitigate through changed forest practices. The forest fire, on the other hand, was conceptualized as a partly natural and partly man-made disaster, and forestry was seen as having very limited possibilities to reduce the likelihood as well as the consequences of similar events. The different understandings had significant implications for the post-disaster dynamics and for which management practices that were developed. Thus, understanding how extreme events are perceived is crucial to understanding which management practices that emerge in their wake, a topic of growing relevance because climate change is predicted to increase the frequency of forest fires and storms.     

Addressing climate change in the forest vegetation simulator to assess impacts on landscape forest dynamics

To simulate stand-level impacts of climate change, predictors in the widely used Forest Vegetation Simulator (FVS) were adjusted to account for expected climate effects. This was accomplished by: (1) adding functions that link mortality and regeneration of species to climate variables expressing climatic suitability, (2) constructing a function linking site index to climate and using it to modify growth rates, and (3) adding functions accounting for changing growth rates due to climate-induced genetic responses. For three climatically diverse landscapes, simulations were used to explore the change in species composition and tree growth that should accompany climate change during the 21st century. The simulations illustrated the changes in forest composition that could accompany climate change. Projections were the most sensitive to mortality, as the loss of trees of a dominant species heavily influenced stand dynamics. While additional work is needed on fundamental plant–climate relationships, this work incorporates climatic effects into FVS to produce a new model called Climate–FVS. This model provides for managers a tool that allows climate change impacts to be incorporated in forest plans.     

Analysis of potential impacts of climate change on forests of the United States Pacific Northwest

As global climate changes over the next century, forest productivity is expected to change as well. Using PRISM climate and productivity data measured on a grid of 3356 plots, we developed a simultaneous autoregressive (SAR) model to estimate the impacts of climate change on potential productivity of Pacific Northwest (PNW) forests of the United States. Productivity, measured by projected potential mean annual increment (PMAI) at culmination, is explained by the interaction of annual temperature, precipitation, and precipitation in excess of evapotranspiration through the growing season. By utilizing information regarding spatial error in the SAR model, the resulting spatial bias is reduced thereby improving the accuracy of the resulting maps. The model, coupled with climate change output from four generalized circulation models, was used to predict the productivity impacts of four different scenarios derived from the fourth IPCC special report on emissions, representing different future economic and environmental states of the world, viz., scenario A1B, A2, B1 (low growth, high economic development and low energy usage), and COMMIT. In these scenarios, regional average temperature is expected to increase from 0.5 to 4.5 °C, while precipitation shows no clear trend over time. For the west and east side of the Cascade Mountains, respectively, PMAI increases: 7% and 20% under A1B scenario; 8% and 23% under scenario A2; 5% and 15% under scenario B1, and 2% and 5% under the COMMIT scenario. These projections should be viewed as potential changes in productivity, since they do not reflect the mitigating effects of any shifts in management or public policy. For managers and policy makers, the results suggest the relative magnitude of effects and the potential variability of impacts across a range of climate scenarios.     

石泉县园林绿化植物主要害虫种类及危害性研究

选设6个具有代表性的调查样点对石泉县园林绿化植物主要虫害进行了调查,研究了叶部害虫、枝干害虫、刺吸害虫等主要害虫的危害性,最后分析了园林绿化植物主要害虫对县城环境的影响,并提出了相应的害虫防控建议。