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Abstract: This paper provides an account of ‘vital ecosystem security’. The central claim is that ‘vital ecosystem security’ and the processual ontology of ‘complex adaptive becoming’ provide useful terms with which to think environmental citizenship biopolitically within the contingent matrix of climate change. The paper identifies how complex adaptation, the operative form of vital ecosystem security, defines an emerging form of environmental citizenship, which can be found operating at the interface of a new type of forestry and the global carbon cycle. The specific case developed here concerns the boreal forest of northern Canada. [Copyright &y& Elsevier]

A variety of evidence suggests that the boreal forests of Canada are responding to climate change. Specifically, several studies have inferred that widespread browning trends detected in time series of the Normalized Difference Vegetation Index (NDVI) from the Advanced Very High Resolution Radiometer (AVHRR) reflect the response of boreal forests to longer growing seasons, increased summer drought stress, and higher frequency of fires. Data from the Thematic Mapper (TM5) and Enhanced Thematic Mapper Plus (ETM+) sensors onboard Landsat 5 and 7, respectively, span essentially the same time period as the AVHRR record, but provide data with substantially higher radiometric and spatial fidelity, and by extension, a much improved basis for evaluating decadal-scale trends in spectral vegetation indices such as the NDVI. However, detection of trends, which are often subtle, requires careful attention to ensure that artifacts associated with the quality and stability of inter- and intra-sensor calibration do not lead to spurious conclusions in results from time series analyses. In this paper, we use time series of TM5 and ETM+ images for fifteen sites distributed across the Canadian boreal forest zone to explore if and how sensor geometry and inter- and intra-sensor calibration affect trends in spectral vegetation indices derived from multi-decadal Landsat time series. To do this, we created annual cloud-free composites for each Landsat spectral band based on peak summer NDVI at each site from 1984 to 2011 using all available TM5 and ETM+ data. To distinguish trends arising from long term climate change from those related to disturbance, we isolated areas within each site that were undisturbed during the Landsat record, and used these locations to analyze sources of variance in time series of red reflectance, near-infrared (NIR) reflectance, the NDVI, and the Enhanced Vegetation Index (EVI). Our results highlight the challenges involved in distinguishing trends in surface properties from data artifacts caused by undetected atmospheric effects, changes in sensor view angles, and subtle radiometric differences between the TM5 and ETM+ sensors. In particular, differences in sensor view geometry across adjacent overlapping Landsat scenes cause vegetated pixels in the eastern portion of Landsat scenes to have higher reflectances in the red and NIR bands (by 5 and 6 percent, respectively) than pixels in the western portion of scenes. While this effect does not significantly change NDVI values, it does affect EVI values. We also found modest, but potentially significant, differences between the red band reflectance of each sensor, with TM5 data having 14 percent higher red reflectance on average for vegetated pixels, which can introduce spurious trends in time series that combine TM5 and ETM+ data. More generally, the results from this work demonstrate that while the 30 + year Landsat archive provides unprecedented opportunities for studying changes to the Earth's terrestrial biosphere over the last three decades, care must be taken when inferring trends in these data without considering how sources of variance unrelated to surface processes affect the integrity of Landsat time series. [ABSTRACT FROM AUTHOR]

• Yield capacity describing forest site productivity was expressed through site index. • Observations from permanent plots in long-term experiments give valid reference estimates of total volume production. • Variations in volume yield levels are explained in a larger extent by basal area levels. • The yield capacity functions can be used to compare tree species' production under similar management regimes. • The functions offer far-reaching support for assessing climate change mitigation potential of boreal forests in northern Europe. Information on forest site productivity is a key component to assess the carbon sequestration potential of boreal forests. While site index (SI) is commonly used to indicate forest site productivity, expressions of SI in the form of yield capacity (potential maximum mean annual volume increment) is desirable since volume yield is central to the economic and ecological analyses of a given species and site. This paper assessed the functional relationship between SI and yield capacity on the basis of yield plot data from long-term experiments measured over several decades for Norway spruce (Picea abies), Scots pine (Pinus sylvestris), Lodgepole pine (Pinus contorta) and Larch (Larix decidua and Larix sibirica) in Sweden. Component models of total basal area and volume yield were also developed. SI was determined by existing height development functions using top height and age, whereas functions for stand-level (m2 ha−1) basal area development were constructed based on age, SI and initial stand density using difference equations and nonlinear mixed-effects models. The relation between volume yield (m3 ha−1) and top height was adjusted with total basal area production through nonlinear mixed-effects models. Species-specific parametric regression models were used to construct functional relationships between SI and yield capacity. The root mean square errors of the species-specific models ranged from 2 to 6% and 10–18% of the average values for the basal area and volume equations, respectively. For the yield capacity functions, the explained variations (R2) were within 80–96%. We compared our yield capacity functions to earlier functions of the species and significant differences were observed in both lower and higher SI classes, especially, for Scots pine and Norway spruce. The new functions give better prediction of yield capacity in current growing conditions; hence, they could later be used for comparing tree species' production under similar site and management regimes in Sweden. [ABSTRACT FROM AUTHOR]

• The ecosystem carbon pool of late-successional and pioneer forests was compared. • Larch, birch and mixed larch-birch stands were studied in the southern boreal zone. • Biomass C stock density was reduced by 7 and 19% in mixed or birch forest. • Soil organic C density remained stable despite disturbance. The boreal forest biome is prominent for its high organic carbon pools, the stability of which is important for climate change mitigation. Natural and anthropogenic disturbance is converting boreal forests from late-successional conifer stands to broadleaved pioneer forests. The present paper analyzes how the degradation of Larix sibirica forest to mixed Betula platyphylla-L. sibirica stands or finally to monospecific B. platyphylla forest affects organic carbon stock density in Mongolia's boreal forests, which are representative of large forest areas at the southern fringe of this biome in Inner Asia. Conversion of larch forest to mixed forest with 60% larch and 40% birch resulted in the reduction of carbon stock density by 7%, whereas the complete replacement of larch by birch reduced ecosystem carbon stock density by 19%. These reductions only referred to biomass stocks, whereas the soil organic carbon stock remained stable indicating that losses during and after the disturbance were offset by carbon sequestration in the highly productive initial stages of pioneer forests. The magnitude of carbon stock degradation by conversion into broadleaved pioneer forest suggests that the existing estimate of 1.5–1.7 Pg C for the total organic carbon pool in Mongolia's boreal forest is not substantially affected by the present level of forest conversion resulting in a share of 6.4% of birch in Mongolia's total forest area, but could become more relevant with progressive degradation of late-successional forests. [ABSTRACT FROM AUTHOR]

To mitigate greenhouse gas and comply with cap-and-trade systems, the carbon capture and storage (CCS) is presently unviable for industrials dealing with low concentration of CO2 emissions. Alternatively, a new offset opportunity is being analysed in Canada: the afforestation of open woodlands (OWs) in the boreal territory. The results obtained from model simulations (with CBM-CFS3) showed that afforestation of boreal OWs can be a low C-intensive mitigation activity, in particular when understory planting is the chosen silvicultural approach, so that only 8-12 years are needed to reach a net positive C balance with the afforestation of OWs. A large-scale afforestation of boreal OWs - scheduled at 20kha per year during 20 years for a maximum of 400 kha - could provide capped industrials with a significant offset potential, for instance up to nearly 8% offset of all Quebec industrial process emissions (2009 data) after 45 years. In spite of a certain number of issues that can contribute to the uncertainty of the real environmental and economical benefits from the afforestation of OWs as a mitigation activity - most of which issues are discussed in this paper - this study presented a first glimpse at the extent to which the afforestation of boreal OWs in Quebec can provide large emitters with eventually substantial and efficient GHG offset potential, especially those emitters tied up with incompressible GHG emissions. [ABSTRACT FROM AUTHOR]

This brief paper indicates that forest fires may have short and longer term effects on runoff and thus, can influence trend studies on the response of watersheds to climate change. Twenty-two watersheds at the Experimental Lakes Area in northwestern Ontario were studied to view the impacts of climatic variability and forest fires on runoff. A roughly 30 year database demonstrated few trends in climatological variables and even fewer trends in runoff data at the 5% significance level. Daily maximum temperature increased by 0.053 °C per year, while precipitation in the months of February and March showed significant decreases. Total snow showed a significant decrease over a 30 year period at the 8% significance level. The Mann Kendall test for trend was applied to the runoff indices of 19 watersheds and it was revealed that only six exhibited trends. Of these, five had been burned during the test period. Virtually all burned watersheds showed initial increases in runoff, however, long term runoff trended lower in the burned watersheds, while the one watershed that was not burned showed an increasing trend. Forest fires alter the age distribution of trees with subsequent impacts on water yields in the short and longer term. [Copyright &y& Elsevier]

Summary: This paper presents a synthesis of the dendroecological work conducted in the area of Lake Duparquet in the southern boreal forest of northwestern Quebec (Canada) during the last 15 years. The topics of these syn- and autecological studies encompassed forest dynamics and tree growth related to natural disturbances such as forest fires, insect outbreaks, and flooding, as well as the effects of climate change. Seven major fire events occurred around Lake Duparquet since 1720: 1760, 1797, 1823, 1847, 1870, 1916, and 1944. Post-fire stand dynamics, established by a chronosequence of over 200 years, are characterized by the gradual transition from broadleaf dominated stands towards mixed and finally almost pure conifer stands. After fire, insect outbreaks are the second most important disturbance type in the southern boreal forest. Spruce budworm, the predominating defoliating insect, but also forest tent caterpillar and larch sawfly have major impacts on growth and stand dynamics of their respective host species. Global warming since the end of Little Ice Age around 1850 coincided with increasing precipitation and, hence, decreasing droughts in the southeastern boreal area of North America. The accelerated radial growth of eastern white-cedar and black ash at Lake Duparquet is a direct effect of these wetter climatic conditions. Population dynamics and forest composition, however, are rather indirectly affected by climate change through the alteration of the natural disturbance regimes, i. e., the decreased frequency and size of the forest fires and the increased frequency and amplitude of the spring floods. Potential consequences of future global warming on disturbance dynamics and forest composition are briefly discussed. The results of the dendroecological studies contributed to the elaboration of a natural-disturbance based forest management model for the southern boreal forest of Quebec. [Copyright &y& Elsevier]