A Life Cycle Analyses (LCA) assessment was evaluated comparing three harvesting systems on intensively managed Pinus radiata (radiata pine) plantations growing in the Biobío Region, Chile. Evaluated ...systems considered semi-mechanized, mechanized, and tower logging in steep slope forest operations. Our LCA study focused on CO
2
e emissions from six harvesting activities: felling, logging, processing, sorting, loading, and transportation, all under the ISO 14040 and ISO 14044 standards. The average and maximum monthly production scenarios were the highest for the semi-mechanized system with 24 and 25.2 kg CO
2
e m
−3
, followed by the tower logging with 23.2 and 24.5 kg CO
2
e m
−3
and, lastly, the mechanized system with 11 and 12.1 kg CO
2
e m
−3
. Similar to other studies, harvesting phases that contributed the most were logging, loading and transport. Concerning LCA stages, forest equipment operation generated the highest CO
2
e level across the three harvesting systems where fuel consumption was the activity that contributed with 76% of CO
2
e for the mechanized system, and 50% in the case of the tower logging and semi-mechanized systems. The mechanized system had the highest fuel use efficiency and the lowest CO
2
e emissions.
Industrial economic models of natural resource management often incentivize the sequential harvesting of resources based on profitability, disproportionately targeting the higher-value elements of ...the environment. In fisheries, this issue is framed as a problem of "fishing down the food chain" when these elements represent different trophic levels or sequential depletion more generally. Harvesting that focuses on high grading the most profitable, productive, and accessible components of environmental gradients is also thought to occur in the forestry sector. Such a paradigm is inconsistent with a stewardship ethic, entrenched in the forestry literature, that seeks to maintain or enhance forest condition over time. We ask 1) how these conflicting paradigms have influenced patterns of forest harvesting over time and 2) whether more recent conservation-oriented policies influenced these historical harvesting patterns. We use detailed harvest data over a 47-y period and aggregated time series data that span over a century on the central coast of British Columbia, Canada to assess temporal changes in how logging is distributed among various classes of site productivity and terrain accessibility, corresponding to timber value. Most of this record shows a distinct trend of harvesting shifting over time to less productive stands, with some evidence of harvesting occurring in increasingly less accessible forests. However, stewardship-oriented policy changes enacted in the mid-1990s appear to have strongly affected these trends. This illustrates both a profit-maximizing tendency to log down the value chain when choices are unconstrained and the potential of policy choices to impose a greater stewardship ethic on harvesting behavior.
•We examine eight steep slope forested headwater catchments (15–100 ha).•Bedload organic carbon (OC), soil carbon and dissolved OC was measured.•OC in the bedload was found to be significantly ...related to catchment area.•Dissolved OC export in stream water declined with catchment area.•There was no difference in OC export from the harvested and non-harvest catchments.
Qualitative and quantitative understandings of the origin, transport and fate of organic carbon (OC) in forest systems is needed to advance our understanding of biogeochemical cycling as well as catchment management and forest harvesting. Here we present the findings from eight steep slope forested catchments dominated by headwater streams (size range 15–100 ha) in south eastern Australia where bedload, organic carbon in bedload, hillslope soil carbon together with dissolved organic carbon has been measured over multiple years. OC in the bedload was found to be significantly related to catchment area (p < 0.02). Dissolved organic carbon export in stream water declined with catchment area. Combined bedload organic carbon and dissolved organic carbon export was significantly related to catchment area. There was no significant difference between hillslope soil organic carbon and bedload organic carbon concentration. When corrected for area, OC export by bedload was not significantly different to that of dissolved OC export. Using the environmental tracer 137Cs it was found that there was no significant difference in tracer concentration between bedload and hillslope soil. This suggests a direct link between hillslope and channel and delivery of organic carbon to the channel. Of the eight catchments examined here, six had been harvested for timber in previous decades (with area of forest removed ranging from 25 to 60%) while two catchments had minimal disturbance (Control catchments- no harvest). There was no difference in organic carbon export from the harvested and Control catchments. The results demonstrate that although land disturbance had previously occurred the management practices employed in each catchment were effective in the long term.
Soil microbial communities regulate the fate of soil organic matter and allow plants to adjust to external conditions, tolerate stresses and modulate their nutrition in forest ecosystems. Yet, the ...long-lasting effects of different forest harvesting intensities on soil microbial communities remain poorly understood. We assessed even-aged (clear-cuts) and uneven-aged (partial harvests; 30% by single-tree selection) management effects on bacterial and fungal abundance and fungal community composition in the forest floor 5, 15 and 30 years after harvesting, relative to unmanaged old-growth controls, in a shade-tolerant hardwood forest in southern Quebec, Canada. Bacteria abundance in even-aged managed forests was significantly higher than in unmanaged forests over both the short- and long-term. Five years after harvesting, fungal species richness in even-aged (331 OTU) and uneven-aged (323 OTU) managed forests was significantly lower than in unmanaged forests (380 OTU). At the same time, fungal community dissimilarity and the proportion of fungal pathogens and parasites in even-aged managed forests were significantly higher than in unmanaged forests. The significant differences in fungal community composition between unmanaged forests and managed forests observed in the short-term (5 years after harvesting) become negligible in the long-term (30 years after harvesting). No significant effect of forest harvesting treatments on the proportion of saprotrophic fungi or fungal phylogenetic diversity was observed. Uneven-aged managed forests and unmanaged forests were associated with higher concentrations of P and C in the forest floor, higher forest density and diversity, and higher proportions of symbiotic fungi.
•Forest harvesting altered soil fungal communities, especially over the shorter-term.•Forest harvesting altered more importantly bacteria than fungi in the forest floor.•Long-undisturbed forests were associated with higher proportions of symbiotic fungi.
Forests provide a series of ecosystem services that are crucial to our society. In the European Union (EU), forests account for approximately 38% of the total land surface
. These forests are ...important carbon sinks, and their conservation efforts are vital for the EU's vision of achieving climate neutrality by 2050
. However, the increasing demand for forest services and products, driven by the bioeconomy, poses challenges for sustainable forest management. Here we use fine-scale satellite data to observe an increase in the harvested forest area (49 per cent) and an increase in biomass loss (69 per cent) over Europe for the period of 2016-2018 relative to 2011-2015, with large losses occurring on the Iberian Peninsula and in the Nordic and Baltic countries. Satellite imagery further reveals that the average patch size of harvested area increased by 34 per cent across Europe, with potential effects on biodiversity, soil erosion and water regulation. The increase in the rate of forest harvest is the result of the recent expansion of wood markets, as suggested by econometric indicators on forestry, wood-based bioenergy and international trade. If such a high rate of forest harvest continues, the post-2020 EU vision of forest-based climate mitigation may be hampered, and the additional carbon losses from forests would require extra emission reductions in other sectors in order to reach climate neutrality by 2050
.
•Industrial forest harvesting changes forest structure and composition.•Studied diet of moose across range of logging intensity.•Forest harvesting can affect diet of moose.
Human-caused landscape ...disturbance is one of the major threats to large herbivores, globally. Across central British Columbia (BC), Canada, industrial forest harvesting has resulted in rapid change to forest structure and composition. Concurrent with the increase in forest harvesting, moose (Alces alces) populations across central BC have declined, some dramatically. We studied moose diet across three seasons in two regional study areas that represented a range of logging intensity and rate of apparent starvation of moose. We used microhistological analysis of pellets to identify the proportional consumption of major plant groups that were known forage for moose across the study areas, as well as the diversity of the diet of moose. We used regression models to test whether the composition and diversity of moose diet in two study areas were consistent with the Niche Expansion Hypothesis or the Niche Shrinkage Hypothesis. In areas of increased density and size of clearcuts, moose consumed fewer shrubs and fir trees and their diet was more diverse. Where application of herbicides was common, moose consumed fewer forbs and their diet was more diverse. Both responses were consistent with the Niche Expansion Hypothesis. In areas of increased disturbance by wildfire, moose consumed less fir and more shrubs. Our results suggest that landscape disturbance in the form of extensive and rapid forest harvesting can influence the composition and diversity of the diet of moose.
•Streamflow was 50% lower in a 40–43-yr-old plantation relative to 110-yr-old forest.•Summer low flow deficits persisted over six or more months of each year.•Contemporary forestry practices produced ...persistent, large summer low flow deficits.
We examined long-term changes in daily streamflow associated with forestry practices over a 60-year period (1959–2017) in the Alsea Watershed Study, Oregon Coast Range, Pacific Northwest, USA. We quantified the response of daily streamflow to (1) harvest of mature/old forest in 1966, (2) 43- to 53-yr and 48- to 58-yr-old industrial plantation forests in 2006–2009, and (3) logging of the plantations using contemporary forest practices, including retention of a riparian buffer, in 2010 and 2014. Daily streamflow from a 40- to 53-yr-old Douglas-fir plantation was 25% lower on average, and 50% lower during the summer (June 15 to Sept 15 of 2006 to 2009), relative to the reference watershed containing mature/old forest. Low flow deficits persisted over six or more months of each year. Surprisingly, contemporary forest practices (i.e., clearcutting of the plantation with riparian buffers in 2009 and 2014) had only a minor effect on streamflow deficits. Two years after logging in 2014, summer streamflow deficits were similar to those observed prior to harvest (under 40- to 53-yr-old plantations). High evapotranspiration from rapidly regenerating vegetation, including planted Douglas-fir, and from the residual plantation forest in the riparian buffer appeared to explain the persistence of streamflow deficits after logging of nearly 100% of the forest plantation. Results of this study indicated that 40- to 50-yr rotations of Douglas-fir plantations can produce persistent, large summer low flow deficits. While the clearcutting of these plantations, with retention of riparian buffers, increased daily streamflow slightly, flows did not return to pre-first entry conditions. Further work is needed to examine how intensively managed plantation forests along with expected warmer, drier conditions in the future may influence summer low streamflow and aquatic ecosystems.
•The literature related to forest harvesting on drained peatlands was reviewed.•Focus on identifying the best practices for mitigation of water quality deterioration.•So far no practices to ...effectively mitigate all harmful consequences concurrently.•So far no practices to mitigate DOC and dissolved organic nutrient exports.•Future studies should focus on assessing the impacts of partial harvestings.
We reviewed the studies on the impacts of forest harvesting on nutrient, sediment, and dissolved organic carbon (DOC) exports from drained peatlands with the aim to identify the best practices for mitigation of detrimental water quality impacts. We concluded that so far there are no such practices that would effectively mitigate all harmful consequences of forest harvestings concurrently. Controlling water levels by executing drainage operations immediately after harvesting may decrease the exports of easily soluble and redox-sensitive elements, but the very intensive drainage necessary to lower water levels in highly decomposed peats, as those that typify peats at the clear-felling phase, would result in large exports of sediments and mineral nitrogen. Establishing a wetland buffer area between a forest harvested peatland and the receiving water course may decrease sediment and inorganic nutrient exports, but restored wetland buffers, in particular, may act as a source of DOC and dissolved organic nutrients to receiving water courses. Whole-tree harvesting might decrease nutrient exports in blanket peat areas, but its practical application is hindered by nutritional and forest harvest technology related aspects. We propose that future studies should focus on assessing the impacts of partial harvestings, which so far have received very limited attention.
PDF