Role of Riparian Buffer Systems and its Potential Contribution to Climate Change

Transcription

1 Role of Riparian Buffer Systems and its Potential Contribution to Climate Change Image by:-national Agroforestry Center By: Sowthini Vijayakumar M.Sc. Student School of Environmental Sciences University of Guelph February 12, 2019

2 Introduction Global warming Image: Greenhouse Gas emissions (e.g. - CO 2, CH 4, N 2 O etc.. ) 2

3 Anthropogenic effects Canada s Emission Projections in 2020 and 2030 (Mt CO 2 eq) Figure: Environment and Climate Change Canada 3

4 Global C Cycle: Pg = Mg x 10 9 blue pools Pg ; red fluxes Pg/yr per 1000 initiative Build Soil C to mitigate increased atmospheric CO 2 ( 4

5 Carbon Sequestration Convert atmospheric CO 2 into the reservoirs Image: 5

6 Riparian Buffer Systems Form of agroforestry Water quality C sequestration and mitigating climate change 6

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8 System level C Sequestration (SCS) SCS = ABC + BBC + SOC Total Biomass Carbon Above ground biomass C sequestration (ABC) Below ground biomass C sequestration (BBC) Soil organic carbon sequestration (SOC) 8

9 Objectives I. Quantification of system level carbon as influenced by soil textures (clay, loam), vegetation types (coniferous, deciduous) and age classes [young (<15 years), mature ( 15 years)] II. To compare land use influence on SOC sequestration potential within RBS and in adjacent agricultural lands. 9

10 Adjacent Agricultural land as control Land was entirely agriculture land previously Impact of non-point source contamination to streams Grand River Conservation Authority (GRCA) Planting trees along the streams Under the Rural Water Quality Program Any differences in SOC can be attributed to the influence of buffer plantations 10

11 Site Selection Vegetation Age Soil Texture Vegetation Type Treatment Combination Site Mature Young Clay Loam Clay Loam Deciduous Mature x Clay x Deciduous 2 Coniferous Mature x Clay x Coniferous 5 Deciduous Mature x Loam x Deciduous 8 Coniferous Mature x Loam x Coniferous 7 Deciduous Young x Clay x Deciduous 13a Coniferous Young x Clay x Coniferous 13b Deciduous Young x Loam x Deciduous 11a Coniferous Young x Loam x Coniferous 11b 8 sites were selected 4 sites in each mature and young sites 11

12 Site description Figure 1: Aerial view of the selected locations within the Grand River watershed (GRW), Ontario, Canada. Green spots Mature vegetation sites [02- Mature deciduous loam (MDL), 05- Mature coniferous loam (MCL), 07- Mature coniferous clay (MCC) and 08- Mature deciduous clay (MDC)] and Yellow spots- Young vegetation sites [11- Young deciduous loam (11a - YDL), Young coniferous loam (11b - YCL) and 13- Young deciduous clay (13a - YDC), Young coniferous clay (13b YCC)]. 12

13 Sampled location Site No Riparian Buffer Adjacent Agriculture Site 02 Mature Deciduous Loam (MDL) Soy bean Site 05 Mature Coniferous Loam (MCL) Soy bean Site 08 Mature Deciduous Clay (MDC) Wheat Site 07 Mature Coniferous Clay (MCC) Wheat Site 11a Young Deciduous Loam (YDL) Wheat Site 11b Young Coniferous Loam (YCL) Wheat Site 13b Young Deciduous Clay (YDC) Clover cover crop Site 13b Young Coniferous Loam (YCL) Clover cover crop 13

14 Sampled sites Young deciduous site Young coniferous site Mature deciduous site Mature coniferous site 14

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16 Objective 1 : System level C a) Biomass carbon sequestration in RBS Riparian Buffer Buffer Age Total biomass Annual biomass C carbon [Mg C (3m sequestration [Mg C yr -1 width x 1000m (3m width x 1000m linear linear length)] length)] CO 2 equivalent [Mg C yr -1 (3m width x 1000m linear length)] MDL MCL MDC MCC YDL YCL YDC YCC This study was conducted in the Grand River Watershed, Waterloo Region, Ontario in (MDL- Mature deciduous loam, MCL- Mature coniferous loam, MDC- Mature deciduous clay, MCC- Mature coniferous clay, YDL- Young deciduous loam, YCL- Young coniferous loam, YDC- Young deciduous clay and YCC- Young coniferous clay). 16

17 Mean Soil Organic Carbon Content (Mg C ha -1 ) Mean Soil Organic Carbon Content (Mg C ha -1 ) b) Soil carbon sequestration in RBS MDC MCC YDC YCC MDL MCL YDL YCL Sites 0 MDC MCC YDC YCC MDL MCL YDL YCL Sites a) 0-30 cm depth b) cm depth Figure 2: Mean soil organic carbon content (Mg C ha -1 ) in the sites of riparian buffer systems sampled at 0-30 cm (a) and cm (b) soil depth in Grand river watershed, waterloo region, Ontario in Error bars indicate the standard error of the mean (n=5). 17

18 System level C sequestration Mg C / (3m x 1000m linear length) c) System level C sequestration (Buffer =3m width x 1000m linear length) Biomass C SOC_30 SOC_ MDC MCC YDC YCC MDL MCL YDL YCL RBS Figure 3: System level C sequestration in the sites of riparian buffer systems sampled in Grand river watershed, waterloo region, Ontario in MDC> MDL > MCC >MCL> YDC> YDL> YCC> YCL 18

19 Mean SOC content (Mg C ha -1 ) Objective 2: Effect of land use (RBS Vs. Adjacent Agricultural field) on mean SOC content Riparian buffer a b a b a b a b a a a a a Adjacent Agriculture a a a DC CC DL CL DC CC DL CL Mature Young Figure 4: Comparison of mean SOC content (Mg C ha -1 ) between riparian buffer systems (RBS) and respective adjacent agricultural fields in each site sampled at 0 30 cm depth in Grand river watershed, waterloo region, Ontario in [DC deciduous clay, CC- Coniferous clay, DL- Deciduous loam, CL- Coniferous loam]. With in a site, means followed by the same letter are not significantly different according to a Tukey s multiple range test (P 0.05). Error bars indicate the standard error of the mean (n=5). 19

20 Impact and Significance Research outcome Data set on C sequestration potential in RBS with respect to all considered factors GRCA digitized 11,000 km of liner length of degraded agricultural streams within the 7,000 km 2 of their watershed Recommend tree types based on soil texture For an example: SCS in RBS with deciduous trees (45 years) = 160 Mg C / km linear buffer Grand River Watershed = 11,000 km linear length x 2 sides = 22,000 km SCS = 160 Mg C / km x 22,000 km = 3.52 x 10 6 Mg C (up to 0-60 cm depth) 20

21 Conclusion SOC Sequestration High MDC among mature YDC among young Buffer > Agriculture Annual Biomass Carbon Sequestration Deciduous > Coniferous (Clay and loam) Mature > young System level C Sequestration RBS with Deciduous trees sequestered more irrespective of soil type and vegetation age than Coniferous trees 21

22 Acknowledgement Advisors: Dr. Naresh Thevathsan Dr. Paul Voroney 22

23 Thank you 23