1
|
Imtiazy MN, Paterson AM, Higgins SN, Yao H, Couture S, Hudson JJ. Dissolved organic carbon in eastern Canadian lakes: Novel patterns and relationships with regional and global factors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 726:138400. [PMID: 32315845 DOI: 10.1016/j.scitotenv.2020.138400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 03/02/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
Long-term patterns in dissolved organic carbon (DOC) concentrations in 49 eastern Canadian lakes from four sites were re-examined with a ~ 35-year (~1980-2015) dataset. The study sites were Dorset (number of lakes, n = 8), Experimental Lakes Area (ELA, n = 4), Kejimkujik (n = 26) and Yarmouth (n = 11). Lake DOC patterns were synchronous within each site. However, comparisons of DOC patterns across sites showed that they were synchronous only between the Kejimkujik and Yarmouth locations. Hence, these two sites were pooled into a single Nova Scotia site (NS). Increases in DOC concentration were evident in Dorset, Ontario from 1988 (r2 = 0.78, p < 0.001) and NS from 2000 (r2 = 0.43, p = 0.006). DOC at the ELA in northwestern Ontario had a different pattern compared to the other sites, i.e., DOC had increased earlier (1983-2000), and then, unlike Dorset and NS, neither an increase nor decrease was detected between 2001 and 2015 (p = 0.78). Precipitation and sulfur deposition explained the greatest variance in DOC patterns at the Dorset and NS sites (i.e., precipitation: 21-49% and sulfur deposition: 24-54%). Precipitation was the most important driver of DOC at the ELA. Our results indicate that all the sites have gone through a process of increasing DOC, but at different times. The stabilizing pattern at the ELA since 2001 may suggest that DOC concentrations in ELA lakes have reached, or are approaching a new equilibrium, a phenomenon that was not observed at the other sites. Also, the increase in DOC was not always associated with declining sulfur deposition (e.g., ELA). Therefore, we conclude that there was considerable variation in DOC patterns across this large geographic region of Canada and potential drivers of these patterns were not consistent across these diverse sites.
Collapse
Affiliation(s)
- Md Noim Imtiazy
- Department of Biology, University of Saskatchewan, Collaborative Science Research Building, 112 Science Place, Saskatoon, SK S7N 5E2, Canada.
| | - Andrew M Paterson
- Ontario Ministry of the Environment, Conservation and Parks, Dorset Environmental Science Centre, 1026 Bellwood Acres Road, Dorset, ON P0A 1E0, Canada.
| | - Scott N Higgins
- IISD - Experimental Lakes Area Inc., 111 Lombard Ave. Suite 325, Winnipeg, MB R3B 0T4, Canada.
| | - Huaxia Yao
- Ontario Ministry of the Environment, Conservation and Parks, Dorset Environmental Science Centre, 1026 Bellwood Acres Road, Dorset, ON P0A 1E0, Canada.
| | - Suzanne Couture
- Environment and Climate Change Canada, Water Science and Technology, 105 McGill Street, Montreal, QC H2Y 2E7, Canada.
| | - Jeff J Hudson
- Department of Biology, University of Saskatchewan, Collaborative Science Research Building, 112 Science Place, Saskatoon, SK S7N 5E2, Canada.
| |
Collapse
|
2
|
Meyer-Jacob C, Michelutti N, Paterson AM, Cumming BF, Keller WB, Smol JP. The browning and re-browning of lakes: Divergent lake-water organic carbon trends linked to acid deposition and climate change. Sci Rep 2019; 9:16676. [PMID: 31723150 PMCID: PMC6853936 DOI: 10.1038/s41598-019-52912-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 10/24/2019] [Indexed: 11/15/2022] Open
Abstract
Dissolved organic carbon (DOC) concentrations and water colour are increasing in many inland waters across northern Europe and northeastern North America. This inland-water “browning” has profound physical, chemical and biological repercussions for aquatic ecosystems affecting water quality, biological community structures and aquatic productivity. Potential drivers of this “browning” trend are complex and include reductions in atmospheric acid deposition, changes in land use/cover, increased nitrogen deposition and climate change. However, because of the overlapping impacts of these stressors, their relative contributions to DOC dynamics remain unclear, and without appropriate long-term monitoring data, it has not been possible to determine whether the ongoing “browning” is unprecedented or simply a “re-browning” to pre-industrial DOC levels. Here, we demonstrate the long-term impacts of acid deposition and climate change on lake-water DOC concentrations in low and high acid-deposition areas using infrared spectroscopic techniques on ~200-year-long lake-sediment records from central Canada. We show that acid deposition suppressed naturally higher DOC concentrations during the 20th century, but that a “re-browning” of lakes is now occurring with emissions reductions in formerly high deposition areas. In contrast, in low deposition areas, climate change is forcing lakes towards new ecological states, as lake-water DOC concentrations now often exceed pre-industrial levels.
Collapse
Affiliation(s)
- Carsten Meyer-Jacob
- Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen's University, Kingston, ON, K7L 3J9, Canada. .,Department of Ecology and Environmental Science, Umeå University, 90187, Umeå, Sweden.
| | - Neal Michelutti
- Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen's University, Kingston, ON, K7L 3J9, Canada
| | - Andrew M Paterson
- Dorset Environmental Science Centre, Ontario Ministry of the Environment, Conservation and Parks, Dorset, ON, P0A 1E0, Canada
| | - Brian F Cumming
- Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen's University, Kingston, ON, K7L 3J9, Canada
| | - Wendel Bill Keller
- Cooperative Freshwater Ecology Unit, Vale Living with Lakes Centre, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - John P Smol
- Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen's University, Kingston, ON, K7L 3J9, Canada
| |
Collapse
|
3
|
Emmerton CA, Beaty KG, Casson NJ, Graydon JA, Hesslein RH, Higgins SN, Osman H, Paterson MJ, Park A, Tardif JC. Long-Term Responses of Nutrient Budgets to Concurrent Climate-Related Stressors in a Boreal Watershed. Ecosystems 2018. [DOI: 10.1007/s10021-018-0276-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
4
|
Wu L, Liu X, Fang Y, Hou S, Xu L, Wang X, Fu P. Nitrogen cycling in the soil-plant system along a series of coral islands affected by seabirds in the South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 627:166-175. [PMID: 29426138 DOI: 10.1016/j.scitotenv.2018.01.213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/11/2018] [Accepted: 01/21/2018] [Indexed: 06/08/2023]
Abstract
The nitrogen (N) utilization strategy of plants has become a topic of interest within the field of phytoecology. However, few studies have considered N cycling on coral island ecosystems from the perspective of their evolution. The aim of this study was to test the impacts of biological transport by seabirds, on the sources and uses of N by plants, and pathways of N cycling in soil-plant ecosystems on coral islands. A series of eight coral islands were investigated, five of which were affected to a varying extent by seabirds. The total phosphorus (TP) concentration from avian sources and the δ15N values of total nitrogen (TN) and inorganic nitrogen (IN: NH4+-N, and NO3--N), δ18O of NO3--O, in soils were determined, as well as proxies in plant leaves of two dominant plant species, including TN, the carbon/nitrogen ratio (C/N), and δ13C and δ15N values. The results show that, with an increase of TP, the TN and IN content, and δ15N values in soils all increased. Plant C/N and δ15N values decreased and increased, respectively, as the soil N content increased. When the TN content of the soil was low, the δ15N value in plant leaves was similar to that in soil NO3-, but was much lower than that in soil NH4+. When the soil TN content was high, the δ15N values were similar. Both plants and soil were probably N-limited prior to seabird colonization, with the N source on the barren coral islands originating primarily from atmospheric deposition. With seabird guano input and subsequent pedogenesis, the source of N switched to guano. Under these conditions, most of the N utilized by plants originated from NH4+, while nitrate is dominant for non-seabirds islands. Seabird activities have played a key role in the N dynamics of soil-plant ecosystems at coral islands.
Collapse
Affiliation(s)
- Libin Wu
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, PR China; Anhui Province Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, Anhui 230026, PR China
| | - Xiaodong Liu
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, PR China; Anhui Province Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
| | - Yunting Fang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China
| | - Shengjie Hou
- LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, PR China
| | - Liqiang Xu
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China
| | - Xueying Wang
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, PR China; Anhui Province Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, Anhui 230026, PR China
| | - Pingqing Fu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, PR China
| |
Collapse
|