|Year||Title (Author, Description)||File Download|
Soil Carbon Sequestration and Land-Use Change: Processes and Potential
W. M. Post, and K. C. Kwon
When agricultural land is no longer used for cultivation and allowed to revert to natural vegetation or replanted to perennial vegetation, soil organic carbon can accumulate by processes that essentially reverse some of the effects responsible for soil organic carbon losses from when the land was converted from perennial vegetation.We discuss the essential elements of what is known about soil organic matter dynamics that may result in enhanced soil carbon sequestration with changes in land-use and soil management.We review literature that reports changes in soil organic carbon after changes in land-use that favor carbon accumulation. This data summary provides a guide to approximate rates of SOC sequestration that are possible with management, and indicates the relative importance of some factors that influence the rates of organic carbon sequestration in soil. There is a large amount of variation in rates and the length of time that carbon may accumulate in soil that are related to the productivity of the recovering vegetation, physical and biological conditions in the soil, and the past history of soil organic carbon inputs and physical disturbance. Maximum rates of C accumulation during the early aggrading stage of perennial vegetation growth, while substantial, are usually much less than 100 g C m y . Average rates of accumulation are similar for forest or grassland establishment: 33.8 g C m y and 33.2 g C m y respectively. These observed rates of soil organic C accumulation, when combined with the small amount of land area involved, are insufficient to account for a significant fraction of the missing C in the global carbon cycle as accumulating in the soils of formerly agricultural land.
|Contact ALCES for W. M. Post, and K. C. Kwon, 1999|
Social-Ecological Thresholds in a Changing Boreal Landscape: Insights from Cree Knowledge of the Lesser Slave Lake Region of Alberta, Canada
Parlee, B. L., K. Geertsema, and Lesser Slave Lake Indian Regional Council
Drawing on the traditional ecological knowledge (TEK) of the Lesser Slave Lake Cree, this paper shares understanding of how resource development has affected water, fish, forests, and wildlife as well as the well-being of Cree communities in the Lesser Slave Lake region of Alberta, Canada. In addition to descriptive observations of change, the narratives point to social-ecological thresholds or tipping points in the relationship of Cree harvesters to local lands and resources. Specifically, the study speaks to the echoing effects of ecological loss and degradation on traditional livelihood practices over the last 100 years highlighting the complexity of cumulative effects as well as the challenges of balancing resource development in the region with alternative land uses including those valued by Alberta’s Aboriginal peoples.
|Contact ALCES for Parlee, B. L., K. Geertsema, and Lesser Slave Lake Indian Regional Council, 2012|
Shell Jackpine Mine Expansion Project
Oil Sands Environmental Coalition
The Panel’s responsibilities to determine if the Project is in the public interest and determine if it will create significant adverse effects, is onerous. We believe it would assist the Panel in discharging its responsibility to protect the public interest and make its assessment of the residual impacts, if it ensured that mitigation will, in fact, be implemented and knew the status of its previous recommendations, and commitments made by the proponent on which the Panel and ERCB relied upon – particularly as it relates to Shell’s projects and the projects in the Muskeg River basin.
|Contact ALCES for Oil Sands Environmental Coalition, 2012|
Sediment Production from Forest Roads with Wheel Ruts
Randy b. Foltz and Edward R. Burroughs, Jr.
Artificial rainfall was applied to two sets of paired plots 30.5 m long by 1.52 m wide, each set on a different soil type. One plot in each set contained a wheel rut while the other did not. Measurements of water and sediment yield on rutted plots showed sediment production declined with cumulative runoff while unrutted plots did not show a significant sediment depletion. This difference was a result of concentrated flow versus sheet flow.
|Contact ALCES for Randy b. Foltz and Edward R. Burroughs, Jr., 1990|
Sediment Production and Delivery from Forest Roads and Off-Highway Vehicle Trails in the Upper South Platte River Watershed, Colorado
Matthew J. Welsh
Sediment is a principal cause of impairment to surface water quality. Erosion is a particularly important environmental issue in the Upper South Platte River (USPR) watershed of Colorado because it is the primary source of drinking water for Denver, has a high-value fishery, and several stream reaches are impaired by high levels of sediment. Unpaved roads are often considered a dominant source of sediment in forested watersheds, and off-highway vehicle (OHV) trails are another potentially important but largely unquantified sediment source. The objectives of this study were to: (1) quantify sediment production and delivery from forest road and OHV trail segments in the USPR watershed; (2) test the accuracy of WEPP:Road, SEDMODL2, and two empirical models for predicting sediment production from roads and OHV trails; and (3) compare sediment production, sediment delivery, and sediment yields from forest roads and OHV trails. Rainfall, site characteristics, and sediment production were measured on 14-22 native surface road segments from 2001 to 2006, and these data were used to test the accuracy of WEPP:Road and SEDMODL2. Empirical models for predicting storm-based and annual sediment production were developed from the first four years of data; the last two years of data were used for model testing. Similar measurements on 5-10 OHV trail segments from 2005 to 2006 were used to test WEPP:Road and SEDMODL2. Sediment delivery was assessed by detailed surveys along 17 km of roads and 10 km of OHV trails. In 2006 mean sediment production from the 10 OHV trail segments was 18.5 kg m-2 yr-1, or six times the mean value from the 21 road segments. The percentage of OHV trails connected to streams was 24%, or 70% higher than for roads, largely because more OHV trails were in the valley bottoms. None of the models accurately predicted sediment production from roads or OHV trails, but the performance of SEDMODL2 was greatly improved by calibrating the geology and traffic factors to the study area. SEDMODL2 also could be improved by adjusting the slope factor, better accounting for rill density on native surface roads, and making the rainfall factor dependent on rainfall erosivity rather than rainfall depth. WEPP:Road could be improved by making sediment production decrease rather than increase with higher soil rock content, and increasing the effect of a categorical change from no traffic to low traffic. Road density in the study area is 0.6 km km-2, or three times the density of OHV trails. Multiplying unit area sediment production normalized by summer erosivity times the density, mean active width, and percent connectivity indicates that roads and OHV trails are respectively delivering approximately 1.1 Mg km-2 and 0.8 Mg km-2 of sediment to the stream network per year. Sediment delivery to streams can be reduced by locating roads and OHV trails out of valley bottoms and off steep hillslopes, decreasing segment lengths, and reducing segment slopes.
|Contact ALCES for Matthew J. Welsh, 2008|
Science for a Changing Far North. The Report of the Far North Science Advisory Panel
The Far North Science Advisory Panel
This report describes the vast and largely intact ecological systems of the Far North, and recommends a conservation-matrix approach for land use planning. It recommends landscape-level planning, with benchmark areas and specific features of interest set aside from development, while other areas are designated for active management, and the landscape overall is planned for continuity and resilience of ecological function. Adaptive management provides a means of evaluating management strategies as climate change and economic development proceed. It will require sustained commitment to the collection and sharing of information about the Far North, including scientific and aboriginal traditional knowledge.
|Contact ALCES for The Far North Science Advisory Panel, 2010|
Scenario Planning: a Tool for Conservation in an Uncertain World
Garry Peterson, Graeme Cumming, and Stephen Carpenter
Conservation decisions about how, when, and where to act are typically based on our expectations for the future. When the world is highly unpredictable and we are working from a limited range of expectations, however, our expectations will frequently be proved wrong. Scenario planning offers a framework for developing more resilient conservation policies when faced with uncontrollable, irreducible uncertainty. A scenario in this context is an account of a plausible future. Scenario planning consists of using a few contrasting scenarios to explore the uncertainty surrounding the future consequences of a decision. Ideally, scenarios should be constructed by a diverse group of people for a single, stated purpose. Scenario planning can incorporate a variety of quantitative and qualitative information in the decision-making process. Often, consideration of this diverse information in a systemic way leads to better decisions. Furthermore, the participation of a diverse group of people in a systemic process of collecting, discussing, and analyzing scenarios builds shared understanding. The robustness provided by the consideration of multiple possible futures has served several groups well; we present examples from business, government, and conservation planning that illustrate the value of scenario planning. For conservation, major benefits of using scenario planning are (1) increased understanding of key uncertainties, (2) incorporation of alternative perspectives into conservation planning, and (3) greater resilience of decisions to surprise.
|Contact ALCES for Garry Peterson, Graeme Cumming, and Stephen Carpenter, 2003|
Scenario Analysis to Identify Viable Conservation Strategies in Paraguay’s Imperiled Atlantic Forest
Carlson, M. J., R. Mitchell, and L. Rodriguez
A common challenge facing land use planning is assessment of the future performance of land use options. The challenge can be acute in developing regions where land use is expanding rapidly and funding and data needed for planning are scarce. To inform land use planning for a biosphere reserve located in Paraguay’s Atlantic forest region, a scenario analysis explored the relative merits of conventional and conservation agricultural practices, sustained yield forestry, and protection. Simulations compared the long-term impacts on land cover, biotic carbon, and income of the area’s residents. Ecological and economic decline were projected under conventional practices. Protection and forestry scenarios achieved only small relative improvements to ecological indicators at the cost of reduced economic performance. By addressing the underlying issue of land degradation, conservation agriculture including no-tillage was the most successful land use strategy both ecologically and economically. Identification of conservation agriculture as the most promising land use strategy prioritizes issues that must be addressed to achieve sustainability, most importantly the provision of education and funding to smallholder farmers. We conclude that scenario analysis offers a flexible strategy to integrate available data for the purpose of informing land use planning in data-limited regions such as Paraguay’s Atlantic forest.
|Contact ALCES for Carlson, M. J., R. Mitchell, and L. Rodriguez, 2011|
Scenario analysis in environmental impact assessment: Improving explorations of the future
Peter Duinker and Lorne Greig
Scenarios and scenario analysis have become popular approaches in organizational planning and participatory exercises in pursuit of sustainable development. However, they are little used, at least in any formal way, in environmental impact assessment (EIA). This is puzzling because EIA is a process specifically dedicated to exploring options for more-sustainable (i.e., less environmentally damaging) futures. In this paper, we review the state of the art associated with scenarios and scenario analysis, and describe two areas where scenario analysis could be particularly helpful in EIA: (a) in defining future developments for cumulative effects assessment; and (b) in considering the influence of contextual change, e.g. climate change, on impact forecasts for specific projects. We conclude by encouraging EIA practitioners to learn about the promise of scenario-based analysis and implement scenario-based methods so that EIA can become more effective in fostering sustainable development. Environmental Impact Assessment Review 27 (2007)
|Contact ALCES for Peter Duinker and Lorne Greig, 2007|
Road Sediment Production and Delivery: Processes and Management
Lee MacDonald and Drew B.R. Coe
Unpaved roads are often considered to be the predominant sediment source in forested catchments. In steep, wet climates roads can cause a 10- to 300-fold increase in the landslide erosion rate, and this increase is due to the effects of roads on hillslope flow paths and the structural integrity of hillslopes. The proportion of sediment that is delivered to the stream will generally be very high for road-induced failures in hollows and inner gorge landforms, and much lower for planar hillslope failures. The pulsed input of sediment from roadinduced landsliding can greatly alter stream channel habitat and morphology. Unpaved roads can increase sediment production rates by more than an order of magnitude as a result of road surface erosion. The high surface erosion rate stems from the generation of surface runoff from the highly compacted road travelway, the lack of surface cover, and the availability of fine sediment due to traffic and road maintenance procedures such as grading. Sediment delivery to streams occurs primarily at road-stream crossings and secondarily by road-induced gullies. The proportion of the road network that is connected to the stream network is primarily a function of mean annual precipitation (R2=0.9), and is increased by about 40% in the absence of any engineered drainage structures. The chronic input of the fine sediment from roads can have adverse effects on freshwater aquatic ecosystems as well as coral reefs. Our present understanding of road surface erosion processes is good, but our models to predict road surface erosion and landsliding are much better for relative than absolute predictions. Climate change can greatly increase road-induced landslides and road surface erosion by increasing the magnitude of large storm events and increasing the amount of rain relative to snow. Extensive field surveys also show that relatively few road segments typically generate most of the road-related increases in sediment yields. Road surface erosion, the risk of road-induced landslides, and road sediment delivery can be greatly decreased by improved road designs and maintenance practices. Hence the greatest needs are to develop and provide land managers with the tools for identifying high-risk segments, and then to make the necessary investments in road reconstruction and restoration.
|Contact ALCES for Lee MacDonald and Drew B.R. Coe, 2007|