Mood, B.J., Bonsal, B., Howat, B., Laroque, C.P., 2021. Multi-year white spruce drought legacies in southern Saskatchewan. Forest Ecology and Management, Volume 491: https://doi.org/10.1016/j.foreco.2021.119144
In many regions across western Canada’s boreal forest, drought impacts on long-term white spruce (Picea glauca (Moench) Voss) radial growth are poorly understood. This is also the case for white spruce shelterbelt trees south of their natural range in agricultural regions of the Canadian Prairies. Understanding how white spruce has responded to drought in the past will be vital for management purposes for those who rely on shelterbelts and will help develop a better understanding of how white spruce in the Canadian Boreal Forest will be impacted by climate change. Using tree-rings, we tested how radial growth responds to different drought magnitudes, time-steps, and timing in southern Saskatchewan during and after droughts. White spruce radial growth is statistically associated to 3-month June-August and July-September Standardized Precipitation-Evapotranspiration Index (SPEI) values. Drought severity has a greater impact on radial growth compared to timing and time-step during the drought year and the five years after. Three-month, extreme droughts from July-September appear to have the greatest overall negative impact on white spruce growth in southern Saskatchewan. Our results indicate that white spruce has a complex multi-year response to varying drought conditions in southern Saskatchewan although the physiological mechanisms behind radial growth changes are yet unknown. This research augments our current understanding of white spruce’s drought-growth relationship and provides new information useful for understanding how the shelterbelts in southern Saskatchewan and the Canadian Boreal Forest may respond to different characteristics of moisture deficit conditions in the future where longer and more pronounced droughts are projected to occur.
Kröbel, R., Moore, J., Ni, Y., Mcpherson, A., Poppy, L. Soolanayakanahally, R., Amichev, B., Ward, T., Laroque, C.P., K. Van Rees and F. Akhter. 2020. Demonstration and Testing of the Improved Shelterbelt Component in the Holos Model. Frontiers in Environmental Science. 8. 10.3389/fenvs.2020.00149.
The shelterbelt component of Canada’s whole-farm model Holos was upgraded from an age-determined to a circumference-determined (at breast height) calculation using a multi-stem averaging approach. The model interface was developed around the idea that a shelterbelt could have multiple rows, and a variable species composition within each row. With this, the model calculates the accumulated aboveground carbon in the standing biomass and a lookup table of modeled tree growth is used to add estimates of the belowground carbon. Going from an initial interface that asks for the current state, the model also incorporates an option of past and future shelterbelt plantings. In order to test the model’s suitability, we measured diverse shelterbelts (evergreen, deciduous, shrub type) in southern Saskatchewan, Canada representing commonly planted woody species. By making use of Caragana, Green Ash, Colorado Spruce, Siberian Elm, and a mixed Caragana/Green Ash tree row, we tested how many tree circumference measurements would be required to yield a representative average. Later, these results were incorporated in the Holos model to estimate the accumulated above-and below-ground carbon in each shelterbelt type.
Amichev, B.Y., C.P. Laroque, and K.C.J. Van Rees. 2020. Shelterbelt removals in Saskatchewan, Canada: implications for long-term carbon sequestration. Agroforestry Systems. doi: 10.1007/s10457-020-00484-8
Abstract: Shelterbelt agroforestry systems represent an actively managed historical agricultural resource for which farmers are the driving force, and their decisions have long-term consequences. For decades, detailed records were maintained of millions of trees and shrubs planted in shelterbelts on agricultural fields and farmyards across the Canadian Prairies. However, no records were collected regarding shelterbelt removals. This study quantified the length and carbon (C) stocks of all removed shelterbelts in Saskatchewan for the 2008–2016 period, and identified shelterbelt removal trends across five soil zones. Removals were detected using a recently developed integrated GIS and remote sensing approach, and were land-use features that were mapped as shelterbelts in an inventory map in 2008 but were missing in the classified map in 2016. A total of 2491.2 km of shelterbelts were removed, containing 190.7 GgC (1 Gg = 1000 Mg = 1000 tonnes). The majority of C stock removals were in shrub shelterbelts (107.2 GgC; 1676.6 km), followed by deciduous (78.1 GgC; 719.1 km) and coniferous shelterbelts (5.4 GgC; 95.5 km). Medium (2–3 rows) and wide (> 3 rows) shelterbelts had higher likelihood of being completely removed, while narrow (1 row) shelterbelts were only shortened. Removals in the < 50 m length designs were one- to three-orders of magnitude higher than any other shelterbelt length design. Future shelterbelt removal studies could serve to sustain the carbon sequestration effectiveness of the existing and extensive shelterbelt network on the Canadian Prairies in the long term, and to protect an important agricultural resource that took a very long time to establish.
Amichev, B.Y., C.P. Laroque, K.W. Belcher, M.J. Bentham, and K.C.J. Van Rees. 2020. Shelterbelt systems establishment in Saskatchewan, Canada: a multi-criteria fuzzy logic approach to land suitability mapping. New Forests. doi: 10.1007/s11056-019-09766-1
Abstract: There is lack of guidelines helping land managers to locate suitable areas for planting new shelterbelt agroforestry systems on their landbases. The goal of this study was to create land suitability maps for deciduous, coniferous, and shrub shelterbelt agroforestry systems establishment across a wide range of climatic and soil zones of Saskatchewan, Canada. Spatial shelterbelt data and a suite of 50 predictor variables were analyzed using multivariate principal component analysis (PCA), principal component regression (PCR), fuzzy logic analysis, and GIS mapping techniques. Fifty spatial datasets were used as shelterbelt establishment predictor variables (4 groups): 21 climate (1980–2010 normals), 13 land management, 14 soils, and 2 topographic criteria. A shelterbelt carbon inventory spatial layer was used as the shelterbelt establishment indicator dataset. Using PCA and PCR analyses, the overall importance (cumulative loading: positive or negative) of all predictor variables was determined and used to create shelterbelt suitability maps by means of weighted-sum overlays in GIS. Statistically significant positive correlations between mapped shelterbelt suitability levels and observed mean shelterbelt carbon stocks were used to evaluate the resulting deciduous (4.86 million hectares (Mha) study area; p = 0.0033, R2 = 0.79), coniferous (1.96 Mha; p = 0.0008, R2 = 0.77), and shrub suitability maps (2.06 Mha; p = 0.0002, R2 = 0.83). Additional 8.76, 7.90, and 9.77 Mha were identified as suitable for planting future deciduous, coniferous, and shrub shelterbelt systems, respectively, mapped as above-average or high suitability land. Shelterbelt suitability mapping is a means to delineating and ranking the land across large landscapes. The approach employed in this study can benefit other afforestation and agroforestry adoption studies across Canada and the world.
Mayrinck, R.C., C.P. Laroque, B.Y. Amichev, and K. Van Rees. 2019. Above- and Below-Ground Carbon Sequestration in Shelterbelt Trees in Canada: A Review. Forests 10(10): 922. doi: 10.3390/f10100922.
Abstract: Shelterbelts have been planted around the world for many reasons. Recently, due to increasing awareness of climate change risks, shelterbelt agroforestry systems have received special attention because of the environmental services they provide, including their greenhouse gas (GHG) mitigation potential. This paper aims to discuss shelterbelt history in Canada, and the environmental benefits they provide, focusing on carbon sequestration potential, above- and below-ground. Shelterbelt establishment in Canada dates back to more than a century ago, when their main use was protecting the soil, farm infrastructure and livestock from the elements. As minimal-and no-till systems have become more prevalent among agricultural producers, soil has been less exposed and less vulnerable to wind erosion, so the practice of planting and maintaining shelterbelts has declined in recent decades. In addition, as farm equipment has grown in size to meet the demands of larger landowners, shelterbelts are being removed to increase efficiency and machine maneuverability in the field. This trend of shelterbelt removal prevents shelterbelt’s climate change mitigation potential to be fully achieved. For example, in the last century, shelterbelts have sequestered 4.85 Tg C in Saskatchewan. To increase our understanding of carbon sequestration by shelterbelts, in 2013, the Government of Canada launched the Agricultural Greenhouse Gases Program (AGGP). In five years, 27 million dollars were spent supporting technologies and practices to mitigate GHG release on agricultural land, including understanding shelterbelt carbon sequestration and to encourage planting on farms. All these topics are further explained in this paper as an attempt to inform and promote shelterbelts as a climate change mitigation tool on agricultural lands.
Ha, T.V., B.Y. Amichev, K.W. Belcher, M.J. Bentham, S.N. Kulshreshtha, C.P. Laroque, and K.C.J. Van Rees. 2019. Shelterbelt Agroforestry Systems Inventory and Removal Analyzed by Object-based Classification of Satellite Data in Saskatchewan, Canada. Canadian Journal of Remote Sensing. doi: 10.1080/07038992.2018.154029
Abstract: Shelterbelt agroforestry systems inventory is challenging given their narrow linear feature and extensive distribution. The objective of this study was to evaluate the capability of Sentinel-2A Multispectral Instrument (MSI) and Sentinel-2B Synthetic Aperture Radar (SAR) imagery in (1) delineating shelterbelt tree rows on managed agricultural land in Saskatchewan, Canada, and (2) detecting shelterbelt removal during the period 2008–2016. Contrast split segmentation for the Normalized Difference Vegetation Index (NDVI) and Gaussian filter (line filter) datasets from SAR were executed to delineate feature borders. Seven feature variables from the spectral bands of MSI were used as inputs for an object-based classification using the Random Forest classifier. A resulting land cover map, including the linear features of existing shelterbelts, was created with an overall accuracy of 80% and kappa value of 0.69. Shelterbelt change detection analysis using the land cover map (2016) and a legacy shelterbelt inventory map (2008) showed that 354 km of shelterbelts were removed within the study area (1,400 km2), accounting for 29.8% of the total shelterbelt length present in 2008. Our results demonstrated that the use of Sentinel imagery can provide sufficient information for mapping future shelterbelt planting, as well as allow the detection of shelterbelt removal. Keywords: Tree and shrub shelterbelts; land-cover mapping; tree planting and removal; NDVI; Sentinel imagery
Amadi, C.C, R.E. Farrell, and K.C.J. Van Rees. 2017. Greenhouse gas emissions along a shelterbelt-cropped field transect. Agriculture, Ecosystems and Environment 241: 110-120
Abstract: The influence of shelterbelts on soil properties and crop yield at various distances from the shelterbelt have been studied; however, there are no available data detailing the spatial effects from shelterbelts into adjacent cropped fields on soil-derived greenhouse gas (GHG) emissions. The objective of this study was to quantify, for the first time, changes in soil CO2, CH4 and N2O fluxes along replicate (n = 5) transects extending from the center of the shelterbelt to the center of the adjacent agricultural field. The shelterbelt was a 31-year-old, two-row hybrid poplar-caragana shelterbelt located in the parkland region of Saskatchewan Canada. Soil-derived GHG fluxes were measured using non-steady-state vented chambers placed along parallel transects situated within the shelterbelt strip (0H), at the shelterbelt edge (0.2H), at the edge of the adjacent cropped field (0.5H), and in the cropped field at distances of 40 m (1.5H) and 125 m (5H) from the shelterbelt. Summed over the entire study period, cumulative CO2 emissions were greatest at 0H (8032 ± 502 kg CO2-C ha−1) and lowest at 5H (3348 ± 329 kg CO2-C ha−1); however, the decrease in CO2 emissions at increasing distances away from the shelterbelt was irregular, with soil temperature and organic carbon distribution being the dominant controls. Soil CH4 oxidation was greatest at 0H (−1447 ± 216 g CH4-C ha−1), but decreased as distance from the shelterbelt increased. Conversely, soil N2O emissions were lowest at 0H (345 ± 15 g N2O-N ha−1) but increased with increasing distance from the shelterbelt. Patterns of soil CH4 uptake and N2O emissions were strongly correlated with root biomass, and soil temperature and moisture in the upper 30 cm of the soil profile. Tree root distribution may be a key factor in determining the spatial range of shelterbelt effect on GHG emissions in adjacent fields. Keywords: Shelterbelts; Carbon dioxide; Methane; Nitrous oxide; Greenhouse gases; Hybrid poplar; Caragana; Cropped fields; Agroforestry
Amichev, B.Y., M.J. Bentham, S. Kulshreshtha, C.P. Laroque, J.M. Piwowar, and K.C.J. Van Rees. 2017. Carbon sequestration and growth of six common tree and shrub shelterbelts in Saskatchewan, Canada. Canadian Journal of Soil Science 97(3): 368-381
Abstract: Shelterbelts sequester and store atmospheric carbon as a direct result of the growth of trees and thus present an opportunity for climate change mitigation. The objectives of this paper were to quantify the growth characteristics and to estimate the carbon stocks of six common shelterbelt species in Saskatchewan: hybrid poplar, Manitoba maple, Scots pine, white spruce, green ash, and caragana. Growth curves (3PG) and carbon dynamics (CBM-CFS3) modelling approaches were used to simulate shelterbelt growth and to estimate the carbon stocks in 50 439 km shelterbelts containing the six species. Shelterbelt width ranged from 6.3 to 14.0 m, age ranged from 5 to 100 yr, and tree density ranged from 356 to 791 trees ha−1. The r2 of the growth curve equations ranged from 28% to 97%, with <50% root-mean-square error and <30% bias. The total ecosystem carbon stocks of all shelterbelts of the six species in Saskatchewan were 10.8 Tg C (1 Tg C = 1 million Mg C), of which 3.77 Tg C was sequestered in the soil and shelterbelt biomass since 1990. The climate mitigation potential of the six shelterbelt species, ranging from 1.78 to 6.54 Mg C km−1 yr−1, emphasized the important role that trees can have on the agricultural landscape to mitigate greenhouse gases (GHGs). Planting shelterbelt trees and shrubs on agricultural landscapes is an important strategy for mitigating GHGs. Keywords: 3PG, agroforestry, carbon, CBM-CFS3, greenhouse gases, shelterbelts
Dhillon, G.S. , A. Gillespie, D. Peak and K. Van Rees. 2017. Spectroscopic investigation of soil organic matter composition for shelterbelt agroforestry systems. Geoderma 298: 1-13
Abstract: While the role of agroforestry systems in increasing soil organic matter (SOM) storage has been studied, insufficient information is available on their effect on the chemical composition of SOM. The objective of this study was to determine the carbon (C) functional group chemistry of SOM for shelterbelts and compare it to the adjacent agricultural fields by using attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Carbon K-edge X-ray absorption near edge structure (XANES) spectroscopies. ATR-FTIR spectral analysis indicated larger proportions of conjugated carboxylic and aromatic C groups for hybrid poplar, white spruce and caragana shelterbelts, phenolic C for hybrid poplar and Manitoba maple shelterbelts and aliphatic and aromatic C for Manitoba maple shelterbelts compared to the adjacent agricultural fields. Polysaccharide, ether and alcoholic C functional groups were generally lower for shelterbelts compared to agricultural fields, with the exception of hybrid poplar species. Analysis by C K-edge XANES spectroscopy on a subset of soils showed the accumulation of aromatic C, ketones and carbohydrates in the surface soil layer (0–5 cm) for the shelterbelts compared to agricultural fields. Pearson correlation analysis indicated that the majority of SOM added under the shelterbelts was in the form of plant-derived aromatic, phenolic and carboxylic C groups. The results of this study suggested that the initial composition of litter and its decomposition rate had a strong influence on the composition of SOM under the shelterbelts. The higher proportion of processed forms of SOM, such as ketones, indicated that the SOM for shelterbelts was at a more advanced stage of decomposition compared to agricultural fields; likely due to the surface deposition of litter under shelterbelts.
Dhillon, G.S. and K. Van Rees. 2017. Distribution of soil organic carbon in the light and heavy fractions for six shelterbelt species and their adjacent agricultural fields in Saskatchewan. Canadian Journal of Soil Science 97(4): 732-744
Abstract: Agroforestry systems play an important role in the sequestration of carbon (C) to reduce atmospheric carbon dioxide (CO2) levels. However, the extent of long-term C sequestration will depend on physical stabilization of the sequestered C. This study determined the influence of six major shelterbelt species on soil organic carbon (SOC) distribution in the light- and heavy-density fractions of bulk soil compared with adjacent agricultural fields. Soil samples were collected from the shelterbelts and adjacent agricultural fields and were separated into light and heavy fractions using sodium iodide solution (NaI, density = 1.6 g cm−3) and analyzed for their organic C stocks. Both the light and heavy fractions to a 50 cm soil depth contained higher SOC stocks for the shelterbelts (21 and 91 Mg C ha−1, respectively) compared with the adjacent agricultural fields (14 and 81 Mg C ha−1, respectively). Most SOC added at the 0–10 cm soil depth was in the form of labile light fraction (92%), whereas heavy fraction contributed to 70% of the increase in the SOC stocks at the 10–30 cm soil depth. Increase in light-fraction SOC stocks was higher for coniferous species compared with hardwood species, and accounted for 48%–50% and 28%–31% of the increase in SOC stocks for coniferous and hardwood shelterbelts, respectively. This trend was attributed to the differences in the amount and quality of litter between coniferous and hardwood species. Keywords: soil organic carbon, carbon sequestration, shelterbelts, light fraction, heavy fraction, agroforestry
Dhillon, G.S. and K. Van Rees. 2017. Soil organic carbon sequestration by shelterbelt agroforestry systems in Saskatchewan. Canadian Journal of Soil Science 97(3): 394-409
Abstract: Carbon (C) sequestration through the implementation of agroforestry practices is identified as one of the major strategies in the reduction of carbon dioxide (CO2) emissions from the agricultural sector. The objective of this study was to examine the soil organic carbon (SOC) sequestration potential of major shelterbelt species, including green ash (Fraxinus pennsylvanica), hybrid poplar (Populus spp.), Manitoba maple (Acer negundo), white spruce (Picea glauca), Scots pine (Pinus sylvestris), and caragana (Caragana arborescens), ranging in age from 5 to 63 yr. Soil samples (0–50 cm) were collected for six major shelterbelt species and adjacent agricultural fields, and SOC concentration was determined. Shelterbelts had a significantly higher amount of SOC compared with adjacent agricultural fields, with an average difference of 18.6 Mg C ha−1 in the top 50 cm soil. An additional 3–8 Mg C ha−1 was contained in the tree litter layer. Younger shelterbelts (age less than 20 yr) tended to lose SOC in the early years of shelterbelt establishment. However, the SOC accrual was positively related to shelterbelt stand age. Besides stand age, other shelterbelt stand characteristics, including tree height and diameter, crown width, and amount of surface litter, were also positively correlated with the increase in SOC concentration. The findings of this study support the hypothesis that shelterbelts can lead to a significant amount of SOC sequestration in agroecosystems. Keywords: soil carbon sequestration, soil organic carbon, shelterbelts, agroforestry
Maillet, J. , C. Laroque and B. Bonsal. 2017. A dendroclimatological assessment of shelterbelt trees in a moisture limited environment.Agricultural and Forest Meteorology 237–238: 30–38
Abstract: The goal of this paper is to apply dendroclimatological methods to the analysis of two commonly planted shelterbelt tree species, Fraxinus pennsylvanica (green ash), and Picea glauca (white spruce), to assess their current relationship with climate and determine how their growth may be affected by climate change in the moisture limited region of southeastern Saskatchewan. Spring precipitation and more importantly spring drought, as represented by the standardized precipitation evapotranspiration index (SPEI), were found to be the most important factors controlling the growth of green ash and white spruce in southeastern Saskatchewan. Furthermore, a breakdown in the radial growth-climate relationship was observed in individuals planted far from their typical native ranges, a potential indication of climate induced stress. Considering these findings, and projections of future climate, it is suggested that conditions beyond the northern limit of the artificial green ash range, and into the boreal forest, may become more suitable for green ash growth, while the southern limit of the artificial white spruce range is expected to recede northward. This information can help guide the management of shelterbelt systems in the Canadian Prairies to ensure they provide maximum practical and ecological benefits for now and into the future. Keywords: Dendroclimatology; Agroforestry; Drought; Green ash (Fraxinus pennsylvanica); White spruce (Picea glauca); Shelterbelt
Piwowar, J.M., B.Y. Amichev and K.C.J. Van Rees. 2017. The Saskatchewan Shelterbelt Inventory. Canadian Journal of Soil Science 97(3): 433-438
Abstract: Shelterbelts represent a significant carbon reserve on the agricultural prairie landscape, and knowledge of their extent can be of importance to atmospheric carbon mitigation strategies. We describe the creation of a detailed inventory of the shelterbelts across the agricultural region of Saskatchewan. A total of 262 000 shelterbelts covering over 51 000 km were identified by species composition, row width, stand condition, and type. This inventory is an important baseline for monitoring changes in prairie agroforestry systems arising from climate change and land use conversion. Keywords: FlySask aerial photographs, farm and field shelterbelts, on-screen digitizing, GIS shapefile
Rempel, J.C. , S.N. Kulshreshtha, B.Y. Amichev and K.C.J. Van Rees. 2017. Costs and benefits of shelterbelts: A review of producers’ perceptions and mind map analyses for Saskatchewan, Canada. Canadian Journal of Soil Science 97(3): 341-352
Abstract: The role of shelterbelts within prairie agriculture is changing. In the past, shelterbelts have been promoted and adopted to reduce soil erosion and to protect farmsteads and livestock from harsh prairie climates. Production techniques used today have been changed from when shelterbelts were first introduced as a management practice to reduce erosion. Advances in production technology accompanied with increase in farm size and changes to policy have all contributed to a shift in how shelterbelts are considered within management plans. The objective of this research is to identify the private costs and benefits from adoption and retention of shelterbelts. In the summer of 2013, a survey was conducted of producers and land owners chiefly from Saskatchewan, Canada. It was found that many of the benefits of shelterbelts can be classified as noneconomic and, therefore, are more difficult for producers and land owners to recognize or include within their operations management decisions. Conversely, the costs to producers were easily identified and heavily influenced management decisions. As greenhouse gas management and policy become more of a focus, shelterbelts have the potential to play a major role in climate change mitigation by sequestering significant amounts of atmospheric carbon dioxide (CO2) into the soil and as biomass carbon in above- and belowground parts of planted shelterbelt trees or shrubs. However, most producers do not recognize such benefits within their management decisions, as they are not currently compensated for the benefits that they provide to society. Keywords: shelterbelts, Saskatchewan, costs, benefits, perception
Amadi, C.C., K.C.J. Van Rees and R.E. Farrell. 2016. Soil–atmosphere exchange of carbon dioxide, methane and nitrous oxide in shelterbelts compared with adjacent cropped fields. Agriculture, Ecosystems and Environment 223:123–134
Abstract: Farm shelterbelts are used as a management tool to reduce erosion, conserve moisture, protect crops and buildings, and sequester carbon. Although carbon storage in shelterbelts has been well researched, there have been no measurements of soil trace gas exchange in shelterbelts relative to cropped fields. Our objective was to quantify, for the first time, soil CO2, CH4 and N2O fluxes from shelterbelts and compare them to emissions from adjacent cropped fields to assess their potential for greenhouse gas (GHG) mitigation. During 2013 and 2014, non-steady state vented chambers were used to monitor soil GHG fluxes from nine shelterbelts and their associated cropped fields at three locations within the Boreal plains and Prairies Eco-zones of Saskatchewan Canada. Mean cumulative CO2 emissions from shelterbelt soils were significantly (P < 0.0001) greater than those from cropped fields (i.e., 4.1 and 2.1 Mg CO2-C ha−1 yr−1, respectively). However, soil organic carbon (SOC) storage (0–30 cm) was 27% greater – representing an increase of 28 Mg ha−1 – in the shelterbelts than in the cropped fields. Soil CH4 oxidation was greater (P < 0.0001) in shelterbelts than in adjacent cropped fields (i.e., −0.66 and −0.19 kg CH4-C ha−1 yr−1, respectively) and cropped soils emitted significantly (P < 0.0001) greater quantities of N2O than the shelterbelts (i.e., 2.5 and 0.65 kg N2O-N ha−1 yr−1, respectively). Total seasonal exchange of non-CO2 GHGs was reduced by 0.55 Mg CO2e ha−1 yr−1 in shelterbelts as compared with cropped fields, 98% of which was soil-derived N2O. Patterns of soil temperature, moisture and organic matter distribution beneath shelterbelts suggest a modification in soil micro-environment due to shelterbelt establishment and root activity that, in turn, may be responsible for the observed increase in soil CO2 emissions and CH4 oxidation. Our data demonstrate that shelterbelts have substantial potential to mitigate GHGs by enhancing C storage and reducing N2O emissions, while maintaining a strong CH4 sink. Keywords: Shelterbelts; Carbon dioxide; Methane; Nitrous oxide; Greenhouse gases; Carbon sequestration; Cropped fields; Agroforestry
Amadi, C.C. , K.C.J. Van Rees and R.E. Farrell. 2016. Greenhouse gas mitigation potential of shelterbelts: Estimating farm-scale emission reductions using the Holos model. Canadian Journal of Soil Science 97(3): 353-367
Abstract: Shelterbelts provide an opportunity for carbon (C) sequestration and have the potential to mitigate agricultural greenhouse gas (GHG) emissions. However, the influence of shelterbelts on GHG emissions at the farm scale is poorly understood. We estimated the potential of three shelterbelt tree species: hybrid poplar, white spruce, and caragana at five planting densities, to reduce GHG emissions in a model farm (cereal–pulse rotation). The Holos model, a Canadian farm-level GHG calculator developed by Agriculture and Agri-Food Canada, was used to estimate shelterbelt effects on farm GHG emissions over a 60 yr time frame. The planting densities of the shelterbelts represented 0%, 0.5%, 1.0%, 3.0%, and 5.0% of the total area of an average (688 ha) Saskatchewan farm. The greatest reduction in farm GHG emissions was estimated for hybrid poplar (23.0%) followed by white spruce (17.5%) and caragana (8.2%) — all at the highest planting density. The GHG mitigation by the shelterbelts was attributable primarily (90%–95% of GHG reduction) to C sequestration in tree biomass and in soil organic carbon (SOC) pools, with the remainder due to lower N2O, CH4 emissions, and a reduction in farm energy use. The GHG estimates from Holos agree with field measurements and suggests that species selection will be important for maximizing C sequestration and GHG mitigation potential of shelterbelt systems; conversely, shelterbelt removal from the agricultural landscape suggests an increase of on-farm GHG emissions. Keywords: shelterbelts, greenhouse gas, carbon, model farm, Holos model
Amichev, B.Y., M.J. Bentham, S. Kulshreshtha, W.A. Kurz, C.P. Laroque, J.M. Piwowar, and K.C.J. Van Rees. 2016. Carbon sequestration by white spruce shelterbelts in Saskatchewan: 3PG and CBM-CFS3 model simulations. Ecological Modelling 325:35-46
Abstract: For more than a century, planted shelterbelts in Saskatchewan, Canada have protected farmyards from the elements, decreased soil erosion, sequestered atmospheric carbon, as well as provided many other ecological functions. It is estimated that there are >60,000 km of planted shelterbelts throughout the province, and considerably more in all of the Canadian Prairies. This paper details the overall process of quantifying and mapping the carbon stocks in white spruce (Picea glauca) shelterbelts planted in Saskatchewan. Shelterbelt data collected from field sampling sites, which were identified by a unique site selection approach, were used to parameterize two models for use in shelterbelt systems; an independent data set was used to validate model predictions. Shelterbelt tree growth was modeled with the Physiological Principles in Predicting Growth (3PG) model, and carbon flux and stocks in shelterbelts were modeled with the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3). Annual total ecosystem carbon (TEC) flux in white spruce shelterbelts increased one order of magnitude, from −0.33 to 4.4 Mg C km−1 yr−1, for age 1–25 years, and reached a peak of 5.5 Mg C km−1 yr−1 (age 39 years). An initial soil carbon loss from the shelterbelt, caused by the land-use change, was offset in full by tree growth by age 17, 18, and 21 years for trees planted at 2.0, 3.5, and 5.0 m spacing within a row, respectively. Increase in carbon stocks, after 60 years of growth, was predicted in the litter layer (21.8 Mg C km−1), belowground biomass (26.1 Mg C km−1), and aboveground biomass (117.6 Mg C km−1). Across all the different provincial soils, carbon additions were 106–195 Mg C km−1 in 60-yr-old white spruce shelterbelts. Cumulatively, accounting for eight decades of white spruce shelterbelt planting and tree growth, carbon additions totaled 50,440 Mg C province-wide in 991 km of white spruce shelterbelts. The C additions represented 38% of the province-wide TEC stocks, which totaled 131,750 Mg C. The cumulative carbon storage in all components of planted white spruce shelterbelts far exceeded the initial carbon levels present at the time of shelterbelt planting. Keywords: Carbon stocks maps; 3PG process-based tree growth model; CBM-CFS3 stand-level C simulation model; Planted windbreaks and shelterbelts; Farmland afforestation
Amichev, B.Y., M.J. Bentham, D. Cerkowniak, J. Kort, S. Kulshreshtha, C.P. Laroque, J.M. Piwowar and K.C.J. Van Rees. 2015. Mapping and quantification of planted tree and shrub shelterbelts in Saskatchewan, Canada. Agroforestry Systems 89(1):49-65
Abstract: The Government of Canada’s farm assistance programs have affected >80 % of Canada’s agricultural land base. One important program in the Prairie Provinces was the prairie shelterbelt program (PSP). A significant aspect of the PSP was shelterbelt tree planting to protect farmyard infrastructure and reduce soil erosion. The main goal of this paper was to map historical shelterbelt establishment, total expected shelterbelt length, and total expected number of six common planted shelterbelt species: caragana (Caragana arborescens), green ash (Fraxinus pennsylvanica), Manitoba maple (Acer negundo), Scots pine (Pinus sylvestris), white spruce (Picea glauca Monch), and hybrid poplar (Populus spp.). A clustering approach was designed to group all agricultural ecodistricts (106 total) into clusters (31 total) based on their similarity in 42 variables within five soil zones of Saskatchewan. Correlations between trees ordered through the PSP and observed shelterbelt length (across 2.1 Mha cumulative study area) were used for shelterbelt probability mapping. Mapping accuracy of planted shelterbelts was 48–86 %. Total shelterbelt length (of any species) ranged from 322 to 45,231 km for (in descending order) dark brown > brown > black > dark gray > gray soil zones. Novel decadal time-lapse maps and species-specific shelterbelt maps were produced to capture the progression of shelterbelt establishment for the first time at a province-wide scale which gave a new perspective, in map format, of the expansive impact of the living legacy of the PSP. Shelterbelt data gaps and high priority clusters of agricultural land in Saskatchewan were identified for future shelterbelt research. Keywords: Prairie farm rehabilitation administration (PFRA); Shelterbelt distribution; Ecodistricts; Decadal shelterbelt maps; Soil zones; Species-specific shelterbelt length
Dhillon, G.S., B.Y. Amichev, R. de Freitas and K. Van Rees. 2015. Accurate and Precise Measurement of Organic Carbon Content in Carbonate-Rich Soils. Communications in Soil Science and Plant Analysis 46(21):2707-2720
Abstract: Accurate measurement of soil organic carbon (SOC) is dependent on precise and fast methods for the separation of organic and inorganic carbon. The widely used methods involving thermal decomposition of soil samples at a specific temperature in an automated carbon (C) analyzer are susceptible to interference by carbonates and overestimation of organic C, and thus removal of carbonates by acid pretreatment of samples is recommended. Two carbonate-removal pretreatments including hydrochloric (HCl) acid addition and HCl fumigation are compared using the calcium carbonate (CaCO3) standard and soil samples of varying SOC contents. Both pretreatment methods provided similar measurements of organic C, indicating that both methods are efficient in removal of carbonates present in the soil. However, the HCl fumigation method exhibited greater accuracy and precision compared to the HCl addition method. Hence, SOC measurement procedure involving HCl fumigation as a pretreatment for the removal of carbonates is recommended for carbonate-rich soils. Keywords: Carbon (C) analysis methods comparison; HCl-acid fumigation of carbonaceous soils; soil organic carbon (SOC); soil inorganic carbon (SIC); soil grinding effects on SOC measurement precision
(Book chapter) Kulshreshtha, S.N. and J. Rempel. 2014. Shelterbelts on Saskatchewan farms: An asset or a nuisance. In: (Chapter 3, pp. 37-54) Climate change and forest ecosystems, Eds. S. Lac and M.P. McHenry, Nova Science Publishers
Book Description: This book focuses on climate change and forest ecosystems (impacts, mitigation, vulnerability and adaptation), and includes work from various international institutions that consider forests as part of the solution to address climate change. The book aims to increase the understanding of forest ecosystems dynamics in response to a changing climate; to address deforestation and maximize carbon sequestration in forests and forest products. Community and political issues involved at various project and ecosystem scales are discussed in detail. By advancing and exchanging knowledge that is complimentary to the UNFCCC-IPCC framework, our team of editors and authors hope to add a valuable contribution to address global climate change in relation to forestry and forest ecosystems in vulnerable locations. It includes work from various institutions and international contributors. Book chapters include a wide variety of topics on climate change impacts, mitigation, vulnerability and adaptation of forests. Our team of editors, reviewers, and authors are honored to be part of this project; truly an example of international cooperation and articulation within the climate change community. The chapters and authors of this book were carefully selected through a rigorous peer review process considering publication records, relevant and high quality contributions to this topic, and priming international cooperation. The intended audience includes the international climate change community including: contributors to the UNFCCC-IPCC process, policymakers, consultants, project developers, researchers and their institutions. Climate Change and Forest Ecosystems aims to be a valuable addition to multidisciplinary and international cooperation efforts (programs, cap-and-trade, carbon trade, CDM, REDD, REDD+), to standards developments (e.g., VCS, FSC), governmental and nongovernmental agencies worldwide, and the general public. The editors believe this book is an effective tool to help the international community progress in understanding and management of forest ecosystems under climatic change, and is part of a series to address climate change through international collaboration and cooperation.
Davis, E.L., C.P. Laroque and K. Van Rees. 2013. Evaluating the suitability of nine shelterbelt species for dendrochronological purposes in the Canadian Prairies. Agroforestry Systems 87:713-727
Abstract: Shelterbelts have played an important role in prairie agriculture since the late 1800s; however, little is known about how these shelterbelts may be affected by climate change. The objective of this study was to determine if shelterbelt species, which are heavily influenced by human activity, express a common radial-growth signal within and between trees. The study focused on the annual tree-ring growth of the nine most common shelterbelt species of the Canadian Prairies: Salix acutifolia (Acute willow), Caragana arborescens (caragana, or Siberian pea shrub), Picea pungens (Colorado spruce), Fraxinus pennsylvanica (green ash), Populus sp. (hybrid poplar), Acer negundo (Manitoba maple), Pinus sylvestris (Scots pine), Ulmus pumila (Siberian elm) and Picea glauca (white spruce). Tree core samples were collected near Saskatoon, Saskatchewan using traditional dendrochronological methods. The standardized growth of each species was compared with historical homogenized climate data in order to determine the key monthly climate variables impacting each species. Prior to this analysis, little was known about the suitability of six of these nine species for dendrochronological purposes. It was found that all species crossdate at a significant level, and that the three most significantly correlated climate factors are able to account for up to 37 % of the annual variation in tree-ring growth. The findings of this study suggest that all nine species are suitable, to varying degrees, for future dendrochronological research in the Canadian Prairies as well as having implications for shelterbelt systems elsewhere in the world. The top four species based on four ranking criteria (interseries correlation, mean sensitivity, climate explanatory power, and commonality) were white spruce, acute willow, caragana, and Manitoba maple, and initial results suggest that all species have the potential to be investigated in greater depth. Keywords: Shelterbelts; Agroforestry; Carbon sequestration; Dendroclimatology; Dendrochronology