The article describes the development of the web-based Canadian Forest Service climate change indicator system, referred to as the Forest Change Tracking System. This indicator system was established ...in 2011 with financial support from the Adaptation theme of the Government of Canada Clean Air Agenda. The objectives of the Forest Change Tracking System are to (a) raise awareness and inform on the occurrence and scope of ongoing changes across Canadian forests associated with climate change and to (b) support the inclusion of adaptation into forest management planning and forest-related policies. The development strategy was to focus on a limited number of most relevant indicators and to build on existing capacity in order to produce information on current and future climate change impacts across Canada’s vast forests. An initial list of 141 potential indicators relevant to forestry was compiled through a series of workshops with more than 100 researchers and forest sector stakeholders and through a global scan of climate change indicator initiatives. A rating system based on each indicator’s potential relevance, sensitivity, and feasibility of measurement was used to select a subset of 35 indicators. These indicators fall within three broad systems—climate, forest, and human. Each indicator web page contains information on the relevance of the indicator, graphs, or maps on past trends and future projections across Canada and related links and references. This paper also presents lessons learned, discusses challenges and opportunities, and reviews potential next steps related to the broadening of this indicator system.
Agroforestry is increasingly viewed as an effective means of maintaining or even increasing crop and tree productivity under climate change while promoting other ecosystem functions and services. ...This study focused on soil biochemical properties and resilience following disturbance within agroforestry and conventional agricultural systems and aimed to determine whether soil differences in terms of these biochemical properties and resilience would subsequently affect crop productivity under extreme soil water conditions. Two research sites that had been established on agricultural land were selected for this study. The first site included an 18-year-old windbreak, while the second site consisted in an 8-year-old tree-based intercropping system. In each site, soil samples were used for the determination of soil nutrient availability, microbial dynamics and microbial resilience to different wetting–drying perturbations and for a greenhouse pot experiment with wheat. Drying and flooding were selected as water stress treatments and compared to a control. These treatments were initiated at the beginning of the wheat anthesis period and maintained over 10days. Trees contributed to increase soil nutrient pools, as evidenced by the higher extractable-P (both sites), and the higher total N and mineralizable N (tree-based intercropping site) found in the agroforestry compared to the conventional agricultural system. Metabolic quotient (qCO2) was lower in the agroforestry than in the conventional agricultural system, suggesting higher microbial substrate use efficiency in agroforestry systems. Microbial resilience was higher in the agroforestry soils compared to soils from the conventional agricultural system (windbreak site only). At the windbreak site, wheat growing in soils from agroforestry system exhibited higher aboveground biomass and number of grains per spike than in conventional agricultural system soils in the three water stress treatments. At the tree-based intercropping site, higher wheat biomass, grain yield and number of grains per spike were observed in agroforestry than in conventional agricultural system soils, but in the drought treatment only. Drought (windbreak site) and flooding (both sites) treatments significantly reduced wheat yield and 1000-grain weight in both types of system. Relationships between soil biochemical properties and soil microbial resilience or wheat productivity were strongly dependent on site. This study suggests that agroforestry systems may have a positive effect on soil biochemical properties and microbial resilience, which could operate positively on crop productivity and tolerance to severe water stress.
•Agroforestry may enhance soil nutrient pools and microbial substrate use efficiency.•Agroforestry may increase soil microbial resilience to wetting–drying perturbations.•Relationships between soil properties and wheat growth were context-dependant.•Agroforestry soil may have positive effects on wheat growth and water stress tolerance.
1. Agricultural intensification is one of the main causes of biodiversity loss world-wide. The inclusion of semi-natural features in agricultural landscapes is suggested as a means of enhancing farm ...biodiversity, but this practice may have potential negative effects on yield production. Moreover, little evidence exists for effects of semi-natural features on other components of biodiversity, such as functional diversity. Yet this could provide a more comprehensive understanding of biodiversity-productivity trade-offs. 2. Here, we report the effects of semi-natural woody vegetation on taxonomic and functional diversity, and biomass production of herbaceous species at the field and farm scales by sampling 50 fields, ranging from 0 to 90% woody vegetation cover, on nine similarly managed farms in central-western Spain. 3. We found significant differences in herbaceous species richness among farms. Both taxonomic and functional β-diversity exhibited significant negative relationships with herbage production, highlighting the trade-off between biodiversity and productivity in these agroecosystems. 4. Woody vegetation cover had a significant negative relationship with biomass production and a unimodal relationship with species richness at the field scale. At high values of woody vegetation cover, species richness and functional diversity indices were decoupled, suggesting that at this extreme of the woody vegetation gradient, only herbaceous species with contrasting trait values were present. Our results showed both convergent and divergent patterns of trait values, suggesting that different assembly processes are acting concurrently along the gradient of woody vegetation. 5. Synthesis and applications. Our result indicates that management of woody vegetation may indeed increase both taxonomic and functional diversity, but this may come at the expense of key ecosystem services or other management goals, namely herbage production. Optimization of the trade-off between herbage diversity and productivity can be reached with a woody vegetation cover of c. 30% at the field scale.
► We examine soil and ericad properties 15years after careful logging and scarification. ► These properties differed on trails and protection strips after careful logging. ► Ericad-induced changes in ...soil properties contributed to perpetuate the trail pattern. ► Scarification had a positive effect on ericad reduction but altered C and N availability.
The practice of careful logging has been mandated in northeastern Canada’s coniferous and mixedwood forests as a means of protecting natural regeneration while minimizing soil disturbance by machinery. This practice imposes evenly spaced, parallel trails for circulation of harvesting machinery, while most of the understory and soil is left intact in wide protection strips between the trails. The objective of this study was to examine soil physico-chemical and microbial properties, and ericaceous shrub performance (aboveground biomass) following careful logging and with or without subsequent scarification. By sampling 32 cutover forest sites (formerly black spruce-dominated) in the Abitibi-Temiscamingue region of boreal northwestern Quebec, we evaluated how (a) the presence of alternating bands of protection strips and skid trails (on non-scarified sites), and (b) a scarification treatment consisting of mixing the soil organic layer with the surface mineral soil, influenced soil and vegetation properties over time (4–15years after careful logging). On non-scarified sites, careful logging showed a differential compaction pattern consisting of bands of disturbed zones or trails alternating with protection zones. Both soil properties and ericaceous shrub biomass estimates tracked these alternating compacted and non-compacted areas on the cutover. Soil N (Nt), soil percentage microbial C to total C (Cmic/Ct), and Kalmia angustifolia (Kalmia) and Vaccinium spp. (Vaccinium) aboveground biomass differed on strips and trails 8 and 15years after harvest. The observed differences in ericaceous shrub biomass between strips and trails, and correlations between biomass and soil variables, suggest potential shrub interference with soil processes. These observations suggest that ericaceous species may promote differences in soil properties and plant communities that result in a long-term spatial signature perpetuating the trail pattern. Scarification reduced Kalmia and Vaccinium aboveground biomass and had a negative effect on Cmic/Nmic and Cmic/Ct, 15years after harvest. Forest understory plants, such as ericaceous shrubs, may play a key role in driving belowground properties, forest regeneration, and long-term succession on these sites. Understanding the ecology and spatial distribution of these species may thus have important implications for ecosystem structure and function as well as timber production.
The two major disturbance types of boreal black spruce forest in north— central Quebec, Canada — natural disturbance by wildfire and anthropogenic disturbance by harvest -may affect processes of ...recovery differently and leave distinct postdisturbance soil and vegetation spatial patterns. We tested whether 1) spatial patterns of physico-chemical soil organic layer properties, black spruce diameter and density, and understory ericaceous shrub cover, differ between these two principal disturbance types; 2) operations associated with forest harvest result in distinct, regular spatial patterns of these same variables related to presence of machine trails; and 3) ericaceous shrub presence is a potential factor contributing to the legacy of spatial patterns after harvest. We explored these patterns on black spruce-feathermoss forest stands, including fire-origin stands (18 and 98 years) and stands originating from harvest (16 and 62 years) in central Quebec, Canada. We used two spatial analysis methods, spectral analysis and principal component analysis in the frequency domain, to characterize and relate spatial patterns of these soil and vegetation variables, measured along 50-m transects on each site. Spatial patterns of distribution of soil and vegetation variables were different on the burned and the harvested forest sites. Wildfire gave rise to spatial patterns in soil and vegetation variables at multiple scales, reflecting the complexity generated by variable burn intensity. Patterns following forest harvest were mainly related to the regular structure defined by trails created by logging operations. In contrast to burned sites, ericaceous shrub patterns on harvested sites were strongly associated with spatial arrangements of spruce diameter and density, promoting absence of canopy closure and persistence of trails. Moreover, different spatial signatures did not converge in the long-term (62-98 years) between the two disturbance types. The divergence in spatial structure between natural and anthropogenic disturbances has implications for ecosystem structure and function in the longer term.
Aims Natural disturbances leave long-term legacies that vary among landscapes and ecosystem types, and which become integral parts of successional processes at a given location. As humans change land ...use, not only are immediate post-disturbance patterns altered, but the processes of recovery themselves are likely altered by the disturbance. We assessed whether short-term effects on soil and vegetation that distinguish wildfire from forest harvest persist over 60 years after disturbance in boreal black spruce forests, or post-disturbance processes of recovery promote convergence of the two disturbance types. Methods Using semi-variograms and Principal Coordinates of Neighbour Matrices, we formulated precise, a priori spatial hypotheses to discriminate spatial signatures following wildfire and forest harvest both over the short-(16-18 years) and long-term (62-98 years). Results Both over the short- and the long-term, wildfire generated a wide spectrum of responses in soil and vegetation properties at different spatial scales, while logging produced simpler patterns corresponding to the regular linear pattern of harvest trails and to predisturbance ericaceous shrub patches that persist between trails. Conclusions Disturbance by harvest simplified spatial patterns associated with soil and vegetation properties compared to patterns associated with natural disturbance by fire. The observed differences in these patterns between disturbance types persist for over 60 years. Ecological management strategies inspired by natural disturbances should aim to increase the complexity of patterns associated with harvest interventions.
Les pessières noires à mousses de la forêt boréale du Québec représentent près de 27% du territoire total québécois et se sont historiquement renouvelées selon un régime naturel de feux. Plus ...récemment, les coupes forestières totales ont graduellement laissé la place aux coupes avec protection de la régénération et des sols, qui limitent la circulation de la machinerie à des sentiers de débardage régulièrement espacés. Suite à l'ouverture du couvert forestier par la coupe forestière, les éricacées du sous-étage peuvent compromettre la régénération et la croissance de l'épinette noire. Dans le contexte de la recherche de stratégies d'aménagement forestier qui s'inspirent du régime des perturbations naturelles, l'objectif de cette thèse était de comparer les patrons spatiaux et temporels des propriétés physico-chimiques et microbiologiques du sol organique, de la taille, de la densité et de la régénération de l'épinette noire, et du recouvrement et de la biomasse aérienne des éricacées après feu et après coupe, dans la pessière noire à mousses. Nos résultats démontrent que les feux et les coupes ne laissent pas la même empreinte spatiale. Le feu est à l'origine des patrons à plusieurs échelles qui reflètent l'existence de zones brûlées à différentes intensités. La coupe impose une structure répétitive où les propriétés du sol et de la végétation sont différentes selon la zone occupée sur le parterre de coupe (i.e., sentiers de débardage ou zones de protection). En modifiant les processus et les propriétés du sol, ainsi qu'en affectant la distribution spatiale et la croissance de l'épinette noire selon les différentes zones d'occupation, les éricacées contribuent à maintenir les différences existantes (a) entre les sentiers et les zones de protection, et (b) à l'intérieur des zones de protection, entre les agrégats (i.e., patches) que les éricacées occupaient avant la coupe et les zones où le couvert forestier était fermé. Ces différentes signatures spatiales après feu et après coupe ne convergent pas à long-terme (62-98 ans). Cette thèse constitue un travail de recherche multidisciplinaire qui a apporté des connaissances originales concernant l'adéquation des méthodes numériques aux problématiques écologiques, l'écologie spatiale de la régénération des éricacées et la compréhension des régimes des perturbations naturelles et anthropogéniques, qui est une étape fondamentale au développement raisonné de l'aménagement écosystémique.
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