Elena I. Parfenova

Positive biodiversity-productivity relationship predominant in global forests.

Global biodiversity and productivity The relationship between biodiversity and ecosystem productivity has been explored in detail in herbaceous vegetation, but patterns in forests are far less well understood. Liang et al. have amassed a global forest data set from >770,000 sample plots in 44 countries. A positive and consistent relationship can be discerned between tree diversity and ecosystem productivity at landscape, country, and ecoregion scales. On average, a 10% loss in biodiversity leads to a 3% loss in productivity. This means that the economic value of maintaining biodiversity for the sake of global forest productivity is more than fivefold greater than global conservation costs. Science, this issue p. 196 Global forest inventory records suggest that biodiversity loss would result in a decline in forest productivity worldwide. INTRODUCTION The biodiversity-productivity relationship (BPR; the effect of biodiversity on ecosystem productivity) is foundational to our understanding of the global extinction crisis and its impacts on the functioning of natural ecosystems. The BPR has been a prominent research topic within ecology in recent decades, but it is only recently that we have begun to develop a global perspective. RATIONALE Forests are the most important global repositories of terrestrial biodiversity, but deforestation, forest degradation, climate change, and other factors are threatening approximately one half of tree species worldwide. Although there have been substantial efforts to strengthen the preservation and sustainable use of forest biodiversity throughout the globe, the consequences of this diversity loss pose a major uncertainty for ongoing international forest management and conservation efforts. The forest BPR represents a critical missing link for accurate valuation of global biodiversity and successful integration of biological conservation and socioeconomic development. Until now, there have been limited tree-based diversity experiments, and the forest BPR has only been explored within regional-scale observational studies. Thus, the strength and spatial variability of this relationship remains unexplored at a global scale. RESULTS We explored the effect of tree species richness on tree volume productivity at the global scale using repeated forest inventories from 777,126 permanent sample plots in 44 countries containing more than 30 million trees from 8737 species spanning most of the global terrestrial biomes. Our findings reveal a consistent positive concave-down effect of biodiversity on forest productivity across the world, showing that a continued biodiversity loss would result in an accelerating decline in forest productivity worldwide. The BPR shows considerable geospatial variation across the world. The same percentage of biodiversity loss would lead to a greater relative (that is, percentage) productivity decline in the boreal forests of North America, Northeastern Europe, Central Siberia, East Asia, and scattered regions of South-central Africa and South-central Asia. In the Amazon, West and Southeastern Africa, Southern China, Myanmar, Nepal, and the Malay Archipelago, however, the same percentage of biodiversity loss would lead to greater absolute productivity decline. CONCLUSION Our findings highlight the negative effect of biodiversity loss on forest productivity and the potential benefits from the transition of monocultures to mixed-species stands in forestry practices. The BPR we discover across forest ecosystems worldwide corresponds well with recent theoretical advances, as well as with experimental and observational studies on forest and nonforest ecosystems. On the basis of this relationship, the ongoing species loss in forest ecosystems worldwide could substantially reduce forest productivity and thereby forest carbon absorption rate to compromise the global forest carbon sink. We further estimate that the economic value of biodiversity in maintaining commercial forest productivity alone is

Climate Changes in Siberia

166 billion to

Terrestrial ecosystems and their change

490 billion per year. Although representing only a small percentage of the total value of biodiversity, this value is two to six times as much as it would cost to effectively implement conservation globally. These results highlight the necessity to reassess biodiversity valuation and the potential benefits of integrating and promoting biological conservation in forest resource management and forestry practices worldwide. Global effect of tree species diversity on forest productivity. Ground-sourced data from 777,126 global forest biodiversity permanent sample plots (dark blue dots, left), which cover a substantial portion of the global forest extent (white), reveal a consistent positive and concave-down biodiversity-productivity relationship across forests worldwide (red line with pink bands representing 95% confidence interval, right). The biodiversity-productivity relationship (BPR) is foundational to our understanding of the global extinction crisis and its impacts on ecosystem functioning. Understanding BPR is critical for the accurate valuation and effective conservation of biodiversity. Using ground-sourced data from 777,126 permanent plots, spanning 44 countries and most terrestrial biomes, we reveal a globally consistent positive concave-down BPR, showing that continued biodiversity loss would result in an accelerating decline in forest productivity worldwide. The value of biodiversity in maintaining commercial forest productivity alone—US

The 21st century climate change effects on the forests and primary conifers in central Siberia

166 billion to 490 billion per year according to our estimation—is more than twice what it would cost to implement effective global conservation. This highlights the need for a worldwide reassessment of biodiversity values, forest management strategies, and conservation priorities.

Potential change in forest types and stand heights in central Siberia in a warming climate

This chapter provides observational evidence of climatic variations in Siberia for three time scales: during the past 10,000 years, during the past millennium prior to instrumental observations, and for the past 130 years during the period of large-scale meteorological observations. The observational evidence is appended with the global climate model projections for the twenty-first century based on the most probable scenarios of the future dynamics of the major anthropogenic and natural factors responsible for contemporary climatic changes. Historically, climate of Siberia varied broadly. It was both warmer and colder than the present. However, during the past century, it became much warmer; the cold season precipitation north of 55°N increased, but no rainfall increase over most of Siberia has occurred. This led to drier summer conditions and to increased possibility of droughts and fire weather. Projections of the future climate indicate the further temperature increases, more in the cold season and less in the warm season, significant changes in the hydrological cycle in Central and southern Siberia (summer dryness), ecosystems’ shifts, and changes in the permafrost distribution and stability. Observed and projected frequencies of various extreme events have increased recently and are projected to further increase. While in the north of Siberia, contemporary models predict warmer winters at the end of the twenty-first century and paleoreconstructions hint to warmer summers compared to the present warming observed during the period of instrumental observations. These three groups of estimates are broadly consistent with each other.

Evaluating the Agroclimatic Potential of Central Siberia

This chapter considers the current state of Siberian terrestrial ecosystems, their spatial distribution, and major biometric characteristics. Ongoing climate change and the dramatic increase of accompanying anthropogenic pressure provide different but mostly negative impacts on Siberian ecosystems. Future climates of the region may lead to substantial drying on large territories, acceleration of disturbance regimes, deterioration of ecosystems, and positive feedback to global warming. The region requires urgent development and implementation of strategies of adaptation to, and mitigation of, negative consequences of climate change.

Energy and mass exchange and the productivity of main Siberian ecosystems (from Eddy covariance measurements). 1. heat balance structure over the vegetation season

Siberian Branch, Russian Academy of Sciences ,VNSukachev Institute of Forest,Academgorodok,50/28, Krasnoyarsk, 660036, Russian, ncheby@ksc.krasn.ruSUMMARYRegional studies have shown that winters warmed 2-3 °C while summers warmed 1-2 °C during the1960-2010 period in central Siberia. Increased warming predicted from general circulation models (GCMs) by the end of the century is expected to impact Siberian vegetation. Our goal is to evaluate the consequences of climate warming on vegetation, forests, and forest-forming tree species in central Siberia. We use our envelope-type bioclimatic models of the Siberian forests and major tree conifer species based on three climatic indices which characterise their warmth and moisture requirements and cold resistance, and on one soil factor that charactrises their tolerance to permafrost. Coupling our bioclimatic models with the climatic indices and the permafrost distributions, we predict the potential habitats of forests and forest-forming tree species in current climate conditions and also in the 2080 projected climate. In the 2080 drier climate conditions, Siberian forests are simulated to decrease significantly and shift northwards while forest-steppe and steppe would come to dominate 50 % of central Siberia. Permafrost is not predicted to thaw deep enough to sustain dark (

Energy and mass exchange and the productivity of main Siberian ecosystems (from Eddy covariance measurements). 2. carbon exchange and productivity

Previous regional studies in Siberia have demonstrated climate warming and associated changes in distribution of vegetation and forest types, starting at the end of the 20th century. In this study we used two regional bioclimatic envelope models to simulate potential changes in forest types distribution and developed new regression models to simulate changes in stand height in tablelands and southern mountains of central Siberia under warming 21st century climate. Stand height models were based on forest inventory data (2850 plots). The forest type and stand height maps were superimposed to identify how heights would change in different forest types in future climates. Climate projections from the general circulation model Hadley HadCM3 for emission scenarios B1 and A2 for 2080s were paired with the regional bioclimatic models. Under the harsh A2 scenario, simulated changes included: a 80%–90% decrease in forest-tundra and tundra, a 30% decrease in forest area, a ~400% increase in forest-steppe, and a 2200% increase in steppe, forest-steppe and steppe would cover 55% of central Siberia. Under sufficiently moist conditions, the southern and middle taiga were simulated to benefit from 21st century climate warming. Habitats suitable for highly-productive forests (≥30–40 m stand height) were simulated to increase at the expense of less productive forests (10–20 m). In response to the more extreme A2 climate the area of these highly-productive forests would increase 10%–25%. Stand height increases of 10 m were simulated over 35%–50% of the current forest area in central Siberia. In the extremely warm A2 climate scenario, the tall trees (25–30 m) would occur over 8%–12% of area in all forest types except forest-tundra by the end of the century. In forest-steppe, trees of 30–40 m may cover some 15% of the area under sufficient moisture.

Significant Siberian Vegetation Change is Inevitably Brought on by the Changing Climate

Human beings have traditionally cultivated the fertile soils of the steppe and forest-steppe for agriculture. Forests are predicted to migrate northward in a warmer climate and are likely to be replaced by forest-steppe and steppe ecosystems. We analysed potential climate change impacts on agriculture in south/central Siberia, hypothesizing that agriculture in traditionally cold Siberia may benefit from warming. Current carbon (C) fluxes in agrosystems have also been analysed, as they are important for the development of land use strategies. Potentials for cropping were evaluated based on simple climate indices such as temperature sums above a base of 5 °C (GDD5), and an annual moisture index (AMI), which is the ratio of GDD5 to annual precipitation. Envelope models which determine crop range, and regression models which determine crop yields, were constructed and applied to climate change scenarios for several time frames: 1960–1990, using historic data; and data taken from HadCM3 B1 and A2 scenarios for 2020 and 2090. Analyses of carbon fluxes in agrosystems showed that plant phytomass and soil humus serve as a principal C sink. Mineralization flux forms from phytodetritus decomposition, and recently formed humus includes portions of “used” mobile humus. Currently, the C balance of agrosystems is slightly in deficit: the C loss is 0.25 t ha−1 year−1. From 50 to 85 % of central Siberia is predicted to be climatically suitable for agriculture by the end of the century, and only soil potential would limit crop advance and expansion to the north. Crop production could double. Future Siberian climatic resources could provide the potential for a great variety of crops to grow which previously did not exist on these lands. Traditional Siberian crops could gradually shift as far as 500 km northward (about 50–70 km per decade) if soil conditions are suitable, and new crops which are non-existent today may be introduced in the dry south, which would necessitate irrigation. Agriculture in central Siberia would likely benefit from climate warming. Adaptation measures would sustain and promote food security in a warmer Siberia.

Energy and Mass Exchange and the Productivity of the Main Ecosystems of Siberia (From Eddy Covariance Measurements). 2. Carbon fluxes and productivity

Direct measurements of heat balance (latent heat and sensible heat fluxes) by the eddy covariance method, undertaken in 1998–2000 and 2002–2004, are used to obtain information on the daily, seasonal, and annual dynamics of energy and mass exchange between the atmosphere and the typical ecosystems of Siberia (middle taiga pine forest, raised bog, and true four grass steppe with data for typical tundra) along the Yenisei meridian (90° E).