Author: William Kevin PiersonPublisher:
ISBN:
Category : Carbon
Languages : en
Pages : 132
Book Description
Dissolved and Particulate Organic Matter Dynamics in Stream Ecosystems of the Ouachita Mountains
Author: William Kevin PiersonPublisher:
ISBN:
Category : Carbon
Languages : en
Pages : 132
Book Description
Investigating Fine Particulate Organic Matter Dynamics in a Nutrient Limited Arctic Stream
Author: Genevieve Louise KyselyPublisher:
ISBN:
Category : Periphyton
Languages : en
Pages : 80
Book Description
Ouachita and Ozark Mountains Symposium
Author: Publisher:
ISBN:
Category : Ecosystem management
Languages : en
Pages : 334
Book Description
This volume presents 5-year results of silvicultural treatments associated with ecosystem management research in the Ouachita Mountains of Arkansas. Results from stand-level treatments include regeneration dynamics of pine and hardwood species, effects of treatment on birds and small mammals, mast production, visual quality, oak decline, and organic matter. Pretreatment landscape findings include measurements of woody vegetation; birds, mammals, and herpetofauna; fish communities and trophic structure; hydrology; and evaluation of susceptibility to gypsy moth outbreaks.
Hydrologic Dynamics Control Dissolved Organic Matter Export from Watersheds
Author: Rebecca Anne BellmorePublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Dissolved organic matter (DOM) is an important component of nutrient cycling and energy transfer within and between ecosystems. Understanding controls over the magnitude and quality of DOM that is transferred from soils to surface water is needed to better characterize the terrestrial-aquatic carbon flux and effects of terrestrial DOM on downstream ecosystems. A meta-analysis of the response of in-stream dissolved organic nitrogen concentration (DON) to high flow events indicates that DON typically increases with flow across a wide range of ecosystem types, likely as novel DOM sources in the landscape are mobilized and transported to streams and rivers. Mechanisms controlling DOM export, including dissolved organic carbon (DOC) and DON concentrations and the quality of DOM, were examined in a small agricultural catchment in eastern Washington State. In the soil column, DOC concentration declined and source of DOM shifted from humic-like and plant-derived to microbially-derived with depth through the profile. Across seasons and years, DOM exported via drain discharge during low flows resembled that found deep in the soil profile, and DOM exported during high flows suggests topsoil and litter sources contribute to export. A simple mixing model suggests that litter leachate can contribute over 50% of DOM during peak flow. Based on modeled contributions of litter, topsoil and subsoil DOM during storm events, DOC concentration is over-predicted, except for peak flows, suggesting removal via sorption and/or microbial decomposition in the soil column control DOC export on the timescale of events. Although the character of exported DOM shifts with flow conditions, laboratory incubations suggest bioavailability to the stream sediment microbial community is consistently low, with a maximum of 7% loss over 6 days, indicating exported DOM is likely transported beyond the immediate stream reach. An analysis of anticipated effects of climate change on the flow regime in the catchment projects the wettest years to become more variable, with non-linear effects on the magnitude of DOC export. Finally I explore how climate change assessments can be incorporated into nonpoint source nutrient management plans, despite current uncertainty about the magnitude and timeframe of climate effects on nutrient loading.
Global Change Impacts on Organic Matter Dynamics in Stream Ecosystems
Author: Marian C. PyeSources, Transportation, and Utilization of Dissolved Organic Matter in Groundwater and Streams
Author: P. M. WallisPublisher: Canada. Inland Waters Directorate, Water Quality Branch
ISBN:
Category : Groundwater
Languages : en
Pages : 68
Book Description
"It has long been recognized that streams in their natural state support a great deal more biomass than can be justified by primary production. This is believed to be the result of energy inputs to streams from terrestrial plants and animals which take the form of either Dissolved Organic Matter (DOM.45μ spherical diameter), or Particulate Organic Matter (POM.45μ)"--Introduction, page 1.
The Impact of Terrestrial Dissolved Organic Carbon on Stream Ecosystems Through an Investigation of Hydrologic Sources
Author: Christine McLaughlinPublisher:
ISBN:
Category :
Languages : en
Pages : 202
Book Description
Impact of Dense Water Formations on the Particulate Organic Matter Dynamics
Author: Marion StabholzDissolved Organic Carbon Dynamics in Tallgrass Prairie Streams
Author: Sophie Alexandra HiggsPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Contrary to the previous notion that a stream acts primarily as the transporter of materials from land to oceans, research has shown that in-stream processing of organic matter and nutrients is significant and relevant at a global scale. Dissolved organic carbon (DOC) is the most abundant form of organic carbon in streams and has been demonstrated as an important source of energy supporting stream food webs. Understanding the dynamics of DOC in streams is, therefore, important in determining the contribution of flowing waters to global carbon storage and release. However, DOC exists as many different compounds, varying in source, composition, and quality. The composition of DOC that ends up in streams is partly controlled by the surrounding watershed, and landscape effects on DOC quality and quantity in streams have been observed. In the North American Tallgrass prairie, woody encroachment has led to changes in riparian vegetation, potentially altering the DOC received by the stream, and making it important to understand rates of DOC transformation as landscape alterations continue. The heterogeneity of the DOC pool makes it difficult to fully describe its components and to measure transformation rates. DOC uptake, or biological use, has been estimated through several methods including in-stream additions of various DOC sources and bottle incubations of stream water and sediments. One problem with addition methods for calculating uptake is that the DOC pool is difficult to replicate and additions of simple compounds or organic leachates do not represent total dissolved organic carbon (TDOC) dynamics. Another potential issue is that additions of a labile compound could potentially alter microbial activity through a priming effect and therefore distort ambient DOC uptake estimates. Finally, uptake parameters are mostly calculated assuming benthic uptake while recent studies have shown that planktonic uptake of DOC can also be significant. We conducted this study with these three considerations in mind. In the first chapter, we describe our use of in situ additions of glucose and bur oak leaf leachate in prairie stream reaches and concentrations of specific components to determine uptake dynamics of various specific DOC components, from a simple sugar to more complex plant compounds. We calculated uptake parameters of glucose and two different oak leaf components. We found that using glucose concentrations rather than TDOC concentrations, as has been done in previous studies, to measure uptake parameters resulted in higher uptake rates, indicating the importance of measuring the specific component added. Through leaf leachate additions, we found that an amino acid like component was consistently taken up faster than a humic-like component. The second chapter addresses the questions of uptake location and priming through a series of recirculating chamber incubations. We found that benthic uptake of leaf leachate was more important than that in the water column. Finally, elevated uptake of one leaf leachate component in the presence of glucose indicated a priming effect on microbial DOC uptake.
Author: Sara Trojahn