Controls of Organic Carbon and Nutrient Export from Unmanaged and Managed Boreal Forested Catchments

Understanding the anthropogenic and natural factors that affect runoff water quality is essential for proper planning of water protection and forest management, particularly in the changing climate. We measured water quality and runoff from 10 unmanaged and 20 managed forested headwater catchments (7–12,149 ha) located in Finland. We used linear mixed effect models to test whether the differences in total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) export and concentrations observed can be explained by catchment characteristics, land use, forest management, soil fertility, tree volume and hydrometeorological variables. Results show that much of variation in TOC, TN and TP concentrations and export was explained by drainage, temperature sum, peatland percentage and the proportion of arable area in the catchment. These models explained 45–63% of variation in concentrations and exports. Mean annual TOC export in unmanaged catchments was 56.4 ± 9.6 kg ha−1 a−1, while in managed it was 79.3 ± 3.3 kg ha−1 a−1. Same values for TN export were 1.43 ± 0.2 kg ha−1 a−1 and 2.31 ± 0.2 kg ha−1 a−1, while TP export was 0.053 ± 0.009 kg ha−1 a−1 and 0.095 ± 0.008 kg ha−1 a−1 for unmanaged and managed, respectively. Corresponding values for concentrations were: TOC 17.7 ± 2.1 mg L−1 and 28.7 ± 1.6 mg L−1, for TN 420 ± 45 µg L−1 and 825 ± 51 µg L−1 and TP 15.3 ± 2.3 µg L−1 and 35.6 ± 3.3 µg L−1. Overall concentrations and exports were significantly higher in managed than in unmanaged catchments. Long term temperature sum had an increasing effect on all concentrations and exports, indicating that climate warming may set new challenges to controlling nutrient loads from catchment areas.

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Runoff Water Quality during Drought in a Zero-Order Georgia Piedmont Pasture: Nitrogen and Total Organic Carbon

Journal of Environmental Quality ◽

10.2134/jeq2010.0411 ◽

2011 ◽

Vol 40 (3) ◽

pp. 969-979 ◽

Cited By ~ 8

Author(s):

Dinku M. Endale ◽

Dwight S. Fisher ◽

Lloyd B. Owens ◽

Michael B. Jenkins ◽

Harry H. Schomberg ◽

...

Keyword(s):

Water Quality ◽

Organic Carbon ◽

Total Organic Carbon ◽

Zero Order ◽

Runoff Water ◽

Georgia Piedmont

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Water Quality of Surface Runoff from Grazed Fescue Grassland Watersheds in Alberta

Water Quality Research Journal ◽

10.2166/wqrj.2002.036 ◽

2002 ◽

Vol 37 (3) ◽

pp. 543-562 ◽

Cited By ~ 9

Author(s):

Emmanuel Mapfumo ◽

Walter D. Willms ◽

David S. Chanasyk

Keyword(s):

Water Quality ◽

Electrical Conductivity ◽

Organic Carbon ◽

Surface Runoff ◽

Total Dissolved Solids ◽

Total Carbon ◽

Runoff Water ◽

Dissolved Solids ◽

Heavy Grazing

Abstract A study was conducted at Stavely Research Station, Alberta, to determine the quantity and quality of surface runoff from small grassland watersheds under three grazing intensities, viz. ungrazed, heavy grazing (2.4 animal unit months per hectare, AUM ha-1) and very heavy grazing (4.8 AUM ha-1). The volume of surface runoff varied each year (1998, 1999 and 2000) and also differed across watersheds, with lower runoff in the ungrazed compared with the heavy and very heavy grazed watersheds. Total dissolved solids in surface runoff water ranged between 34 to 360 mg L-1, and that for runoff from the very heavy grazed watershed was greater than that from other watersheds. Electrical conductivity increased with increased grazing intensity on the watershed. In two of three years the very heavy grazed watershed had greater nitrate concentrations than the other two watersheds. In all three years the levels of nitrate were lower than the maximum acceptable level for drinking water (10 mg L-1 as nitrogen). Levels of orthophosphate (PO43-) in surface runoff from all three watersheds and the three years of study were less than 1 mg L-1, and mostly within the range considered typical for rivers and streams. Total carbon (up to 500 mg L-1) was greater than the amounts considered typical for streams and rivers, and most of it was organic carbon. Nuisance organisms such as algae, nematodes, Giardia spp., Cryptosporidium spp. and rotifers were detected in some surface runoff samples. However, no crustaceans were detected. The results of a canonical correlation analysis indicated that the dominant external forcing factors (meteorological and management) in influencing water quality were year of study, water temperature and grazing. Surface runoff discharge did not influence water quality measurements. The dominant water quality parameters were found to be total carbon, organic carbon, total dissolved solids and electrical conductivity. Overall, this study indicated that during the three years, the surface runoff volumes from the watersheds were small and grazing of these watersheds posed little risk of nutrient (e.g., nitrate, ammonia and orthophosphate) contamination of adjacent streams, but organic carbon loading and dissolved solids may be of concern. The presence of parasites was detected in two or less runoff water samples each year, and thus pose little risk of contamination of adjacent streams. However, it may be necessary to monitor parasites especially in areas under cow-calf operations.

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Quantitative and Qualitative Perspectives of Forest-Water Interactions at Catchment Scales

Asian Journal of Research in Agriculture and Forestry ◽

10.9734/ajraf/2019/v3i230036 ◽

2019 ◽

pp. 1-19

Author(s):

Murari Lal Gaur ◽

Shreya M. Gaur

Keyword(s):

Water Quality ◽

Land Use ◽

Forest Management ◽

Water Availability ◽

Water Dynamics ◽

Tree Cover ◽

Hydraulic Redistribution ◽

Knowledge Gaps ◽

Forested Catchments ◽

Ground Water Recharge

Sustaining a resilient and reliable water cycle is a global challenge, which inevitably needs proper understanding and action at many levels. One quarter of the world’s population depends on water from forested catchments, where behavior of atmospheric water nonetheless governs the forest-water interactions and thus the ultimate water availability. As per a coarse estimation the water vapors comprise one quarter of 1% of atmospheric mass being equivalent to just 2.5 centimeters of liquid water over the entire Earth. Such water availability raises more tangible concerns for most people than do temperature and carbon. Ever escalating populations and living standards are badly impacting the earth’s surface in variety of ways, as 1.5 million Km2 of dense tree cover were reported to be lost between 2000-2012, leading to highly impeded access to fresh water. Majority of studies of how forest land use and its change influences climate and hydrology rely on models (mostly imperfect owing to pitiable/incomplete process understandings and poor parameterization). It is projected that land cover changes have caused a 5 to 6 % reduction in global atmospheric wetness. A plethora of alike estimations/inferences are included herein to offer relevant R&D insights on core theme of this paper, by encircling reviews of few global observations and findings towards forest influences on quality and quantity of water. With increasing demand for agricultural and urban land (owing to population/affluent life-styles) majority of forests are put under pressure. At this juncture tropical regions like India remains more crucial, as their water and land use policies are often influenced to big extent by many perceived effects from hydrological functioning of forested catchments. This paper offers certain food for thought by summarizing relevant scientific consensus of key aspects of forest-water relationships and couple of wider aspects towards ‘forest-water interactions’ and ‘water quality and pollution facets. Apprehensions and knowledge gaps about hydrological impacts of forest management and also the emerging futuristic R&D issues are elaborated with specified line of sights on effects of forests and forest management on various stream flow parameters, soil erosion, stream sedimentation, water quality, landslides and water uses. Owing to their inherent capabilities and capacities, the forests govern available moisture for tree growth, evapotranspiration (ET), soil infiltration, ground water recharge, and runoff; hence could be projected as futuristic ‘water towers’. Hydraulic redistribution of water in soil remains other important activities by the forest, where tree root structures plays a vital role to facilitate both upward and downward water dynamics. Even under low to intermediate tree cover each tree remains capable to improve soil hydraulic properties even up to 25 m from its canopy edge, with higher hydrologic gains in comparison to associated additional losses (transpiration and interception). Among most profound and alarming insights offered by this write up are; critical knowledge gaps on understanding importance of forests to water, trends of findings from a few catchments based hydrological experiments on water yield, roles forest may play in regulating water fluxes and rainfall patterns. Other key messages offered for water and forest policy makers includes issues like water use by forests, flood flows, water quality, erosion, climate change, energy forest, and forest water productivities.

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Carbon, Nutrients and Methylmercury in Water from Small Catchments Affected by Various Forest Management Operations

Forests ◽

10.3390/f12091278 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1278

Author(s):

Zane Kļaviņa ◽

Arta Bārdule ◽

Karin Eklöf ◽

Krišs Bitenieks ◽

Ivars Kļaviņš ◽

...

Keyword(s):

Forest Management ◽

Dam Removal ◽

Organic Soils ◽

Forested Catchments ◽

Runoff Water ◽

Beaver Dam ◽

The Impact ◽

Ditch Cleaning ◽

Small Catchments ◽

Management Effects

Forest management activities in boreal and hemiboreal environments have been found to increase the concentration of carbon, nutrients, and methylmercury (MeHg) in runoff water, thus contributing to environmental quality issues. We evaluated carbon, nutrient, and MeHg concentrations in water at eight small, forested catchments on organic soils in Latvia, subject to ditch cleaning and beaver dam removal. These management-induced disturbances were classified into a major, minor, or no disturbance classes. The concentrations of dissolved organic carbon and total nitrogen were elevated in disturbed catchments (both major and minor) compared to the catchments with no disturbance. The concentrations of MeHg in the water displayed a clear seasonal variation with higher concentrations in spring and summer, but there were no significant differences in MeHg concentrations between catchments with major, minor, and no disturbances. However, the higher concentrations of SO42− in the disturbed catchments compared to those undisturbed may promote MeHg formation if the conditions become more reduced further downstream. While most former studies of forest management effects on water quality have focused on forest harvest, our research contributes to the currently rather scarce pool of data on the impact of less-studied management operations, such as ditch cleaning and beaver dam removal, on carbon, nutrient, and MeHg concentrations in runoff water.

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