by Claire Morin | 30 January 2019
Published in Forest Ecology and Management 368: 63-70. https://doi.org/10.1016/j.foreco.2016.02.029
Forest fragmentation by management activities has been implicated in the decline of forest biodiversity. Even though boreal ecosystems are generally deemed quite resilient to disturbance effects, high contemporary levels of disturbance might push forest-interior species toward decline or extinction. In this study, we examined beetle communities in forest patches of different sizes, including clearcuts, residual postharvest patches from 0.03 to 50 ha in size, and large mature forest tracts (>1000 ha). Overall, community structure follows a gradient between clearcuts and large mature forest tracts, even if patch size effects were more difficult to detect among patches >2.5 ha. Beetles were most abundant in clearcuts, and species richness was highest in small tree groups (0.03–0.05 ha). The effects of fragmentation were strongly conditioned by beetle feeding habits. Predators and xylophagous beetles were mostly associated with clearcuts or smaller patches (i.e., small tree groups or large tree groups [0.3–0.5 ha]), whereas fungivorous beetles were associated with forest-interior habitats. Although many forest-interior species were still present in relatively small patches 1–5 years after harvesting, negative effects of habitat fragmentation on these species might increase in the long-term.
by Claire Morin | 30 January 2019
Published in Canadian Journal of Forest Research 45(5): 515-528. https://doi.org/10.1139/cjfr-2014-0260
The boreal forest ecosystem is one of the largest frontier forests of the world, providing many ecological services to society. Boreal forests are also economically important, but forest harvesting and management become increasingly difficult when one moves from south to north in boreal environments. An approach was thus developed to assess the suitability of land units for timber production in a sustainable forest management (SFM) context in the northern boreal forest of Quebec (Canada). This area includes all of Quebec’s spruce – feather moss bioclimatic domain (closed forest), as well as the southern portion of the spruce–lichen bioclimatic domain (open woodland). Four criteria specific to the biophysical aspects of SFM were evaluated in 1114 land districts: physical environment, timber production capacity, forest vulnerability to fire (e.g., probability that it reaches maturity), and conservation of biodiversity. Indicators and acceptability cutoff values were determined for each selected criterion, and a sequential analysis was developed to evaluate if a land district has the potential to be sustainably managed. This analytical process led to the classification of land districts into three categories: slightly sensitive (SFM possible); moderately sensitive (SFM possible under certain conditions); and highly sensitive (SFM not possible). The results show that 354 land districts were highly sensitive, 62 due to physical constraints (7.5% of the area), 130 due to insufficient potential productivity (15.4% of the area), 92 due to insufficient potential productivity to account for the fire risk (13.8% of the area), and 70 due to an insufficient proportion of tall and dense forest habitats (7.7% of the area — biodiversity criterion). This work provides scientific background to proposing a northern limit for forest management activities in Quebec. The developed approach could be useful in other jurisdictions to address similar issues.
by Claire Morin | 30 January 2019
Published in Microbial biotechnology 9(3): 316-329. https://doi.org/10.1111/1751-7915.12348
The impact of mechanical site preparation (MSP) on soil biogeochemical structure in young larch plantations was investigated. Soil samples were collected in replicated plots comprising simple trenching, double trenching, mounding and inverting site preparation. Unlogged natural mixed forest areas were used as a reference. Analysis of soil nutrients, abundance of bacteria and gas exchanges unveiled no significant difference among the plots. However, inverting site preparation resulted in higher variations of gas exchanges when compared with trenching, mounding and unlogged natural forest. A combination of the biological and physicochemical variables was used to define a multifunctional classification of the soil samples into four distinct groups categorized as a function of their deviation from baseline ecological conditions. According to this classification model, simple trenching was the approach that represented the lowest ecological risk potential at the microsite level. No relationship was observed between MSP method and soil bacterial community structure as assessed by high-throughput sequencing of bacterial 16S rRNA gene; however, indicator genotypes were identified for each multifunctional soil class. This is the first identification of multifunctional molecular indicators for baseline and disturbed ecological conditions in soil, demonstrating the potential of applied microbial ecology to guide silvicultural practices and ecological risk assessment.
by Claire Morin | 30 January 2019
Published in PeerJ 4: e1767 https:/doi.org/10.7717/peerj.1767
Biological carbon sequestration by forest ecosystems plays an important role in the net balance of greenhouse gases, acting as a carbon sink for anthropogenic CO2 emissions. Nevertheless, relatively little is known about the abiotic environmental factors (including climate) that control carbon storage in temperate and boreal forests and consequently, about their potential response to climate changes. From a set of more than 94,000 forest inventory plots and a large set of spatial data on forest attributes interpreted from aerial photographs, we constructed a fine-resolution map (~375 m) of the current carbon stock in aboveground live biomass in the 435,000 km2 of managed forests in Quebec, Canada. Our analysis resulted in an area-weighted average aboveground carbon stock for productive forestland of 37.6 Mg ha-1, which is lower than commonly reported values for similar environment. Models capable of predicting the influence of mean annual temperature, annual precipitation, and soil physical environment on maximum stand-level aboveground carbon stock (MSAC) were developed. These models were then used to project the future MSAC in response to climate change. Our results indicate that the MSAC was significantly related to both mean annual temperature and precipitation, or to the interaction of these variables, and suggest that Quebec’s managed forests MSAC may increase by 20% by 2041-2070 in response to climate change. Along with changes in climate, the natural disturbance regime and forest management practices will nevertheless largely drive future carbon stock at the landscape scale. Overall, our results allow accurate accounting of carbon stock in aboveground live tree biomass of Quebec’s forests, and provide a better understanding of possible feedbacks between climate change and carbon storage in temperate and boreal forests.
