scholarly journals Integrating Aquatic Metabolism and Net Ecosystem CO2 Balance in Short- and Long-Hydroperiod Subtropical Freshwater Wetlands

Ecosystems ◽  
2021 ◽  
Author(s):  
Sparkle L. Malone ◽  
Junbin Zhao ◽  
John S. Kominoski ◽  
Gregory Starr ◽  
Christina L. Staudhammer ◽  
...  
Keyword(s):  
Water Level ◽  
Primary Productivity ◽  
National Park ◽  
Significant Contribution ◽  
Ecosystem Respiration ◽  
Freshwater Wetlands ◽  
Aquatic Respiration ◽  
C Dynamics ◽  
Co2 Balance ◽  
Marl Prairie

AbstractHow aquatic primary productivity influences the carbon (C) sequestering capacity of wetlands is uncertain. We evaluated the magnitude and variability in aquatic C dynamics and compared them to net ecosystem CO2 exchange (NEE) and ecosystem respiration (Reco) rates within calcareous freshwater wetlands in Everglades National Park. We continuously recorded 30-min measurements of dissolved oxygen (DO), water level, water temperature (Twater), and photosynthetically active radiation (PAR). These measurements were coupled with ecosystem CO2 fluxes over 5 years (2012–2016) in a long-hydroperiod peat-rich, freshwater marsh and a short-hydroperiod, freshwater marl prairie. Daily net aquatic primary productivity (NAPP) rates indicated both wetlands were generally net heterotrophic. Gross aquatic primary productivity (GAPP) ranged from 0 to − 6.3 g C m−2 day−1 and aquatic respiration (RAq) from 0 to 6.13 g C m−2 day−1. Nonlinear interactions between water level, Twater, and GAPP and RAq resulted in high variability in NAPP that contributed to NEE. Net aquatic primary productivity accounted for 4–5% of the deviance explained in NEE rates. With respect to the flux magnitude, daily NAPP was a greater proportion of daily NEE at the long-hydroperiod site (mean = 95%) compared to the short-hydroperiod site (mean = 64%). Although we have confirmed the significant contribution of NAPP to NEE in both long- and short-hydroperiod freshwater wetlands, the decoupling of the aquatic and ecosystem fluxes could largely depend on emergent vegetation, the carbonate cycle, and the lateral C flux.

scholarly journals Net Primary Productivity of Subalpine Meadows in Yosemite National Park in Relation to Climate Variability

2013 ◽  
Vol 73 (4) ◽  
pp. 409-418 ◽  
Author(s):  
Peggy E. Moore ◽  
Jan W. van Wagtendonk ◽  
Julie L. Yee ◽  
Mitchel P. McClaran ◽  
David N. Cole ◽  
...  
Keyword(s):  
Climate Variability ◽  
Primary Productivity ◽  
National Park ◽  
Net Primary Productivity ◽  
Yosemite National Park ◽  
Subalpine Meadows

scholarly journals Assessment of model estimates of land-atmosphere CO<sub>2</sub> exchange across Northern Eurasia

2015 ◽  
Vol 12 (14) ◽  
pp. 4385-4405 ◽  
Author(s):  
M. A. Rawlins ◽  
A. D. McGuire ◽  
J. S. Kimball ◽  
P. Dass ◽  
D. Lawrence ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Soil Carbon ◽  
Residence Time ◽  
Primary Productivity ◽  
Ecosystem Respiration ◽  
Regional Scale ◽  
Northern Eurasia ◽  
Sink Strength ◽  
Vegetation Productivity ◽  
Co2 Sink

Abstract. A warming climate is altering land-atmosphere exchanges of carbon, with a potential for increased vegetation productivity as well as the mobilization of permafrost soil carbon stores. Here we investigate land-atmosphere carbon dioxide (CO2) cycling through analysis of net ecosystem productivity (NEP) and its component fluxes of gross primary productivity (GPP) and ecosystem respiration (ER) and soil carbon residence time, simulated by a set of land surface models (LSMs) over a region spanning the drainage basin of Northern Eurasia. The retrospective simulations cover the period 1960–2009 at 0.5° resolution, which is a scale common among many global carbon and climate model simulations. Model performance benchmarks were drawn from comparisons against both observed CO2 fluxes derived from site-based eddy covariance measurements as well as regional-scale GPP estimates based on satellite remote-sensing data. The site-based comparisons depict a tendency for overestimates in GPP and ER for several of the models, particularly at the two sites to the south. For several models the spatial pattern in GPP explains less than half the variance in the MODIS MOD17 GPP product. Across the models NEP increases by as little as 0.01 to as much as 0.79 g C m−2 yr−2, equivalent to 3 to 340 % of the respective model means, over the analysis period. For the multimodel average the increase is 135 % of the mean from the first to last 10 years of record (1960–1969 vs. 2000–2009), with a weakening CO2 sink over the latter decades. Vegetation net primary productivity increased by 8 to 30 % from the first to last 10 years, contributing to soil carbon storage gains. The range in regional mean NEP among the group is twice the multimodel mean, indicative of the uncertainty in CO2 sink strength. The models simulate that inputs to the soil carbon pool exceeded losses, resulting in a net soil carbon gain amid a decrease in residence time. Our analysis points to improvements in model elements controlling vegetation productivity and soil respiration as being needed for reducing uncertainty in land-atmosphere CO2 exchange. These advances will require collection of new field data on vegetation and soil dynamics, the development of benchmarking data sets from measurements and remote-sensing observations, and investments in future model development and intercomparison studies.

scholarly journals Technical note: Dynamic INtegrated Gap-filling and partitioning for OzFlux (DINGO)

2017 ◽  
Vol 14 (6) ◽  
pp. 1457-1460 ◽  
Author(s):  
Jason Beringer ◽  
Ian McHugh ◽  
Lindsay B. Hutley ◽  
Peter Isaac ◽  
Natascha Kljun
Keyword(s):  
Primary Productivity ◽  
Active Sites ◽  
Ecosystem Respiration ◽  
Technical Note ◽  
Gross Primary Productivity ◽  
Quality Data ◽  
Gap Filling ◽  
Continental Scale ◽  
Flux Data ◽  
Processing Pathways

Abstract. Standardised, quality-controlled and robust data from flux networks underpin the understanding of ecosystem processes and tools necessary to support the management of natural resources, including water, carbon and nutrients for environmental and production benefits. The Australian regional flux network (OzFlux) currently has 23 active sites and aims to provide a continental-scale national research facility to monitor and assess Australia's terrestrial biosphere and climate for improved predictions. Given the need for standardised and effective data processing of flux data, we have developed a software suite, called the Dynamic INtegrated Gap-filling and partitioning for OzFlux (DINGO), that enables gap-filling and partitioning of the primary fluxes into ecosystem respiration (Fre) and gross primary productivity (GPP) and subsequently provides diagnostics and results. We outline the processing pathways and methodologies that are applied in DINGO (v13) to OzFlux data, including (1) gap-filling of meteorological and other drivers; (2) gap-filling of fluxes using artificial neural networks; (3) the u* threshold determination; (4) partitioning into ecosystem respiration and gross primary productivity; (5) random, model and u* uncertainties; and (6) diagnostic, footprint calculation, summary and results outputs. DINGO was developed for Australian data, but the framework is applicable to any flux data or regional network. Quality data from robust systems like DINGO ensure the utility and uptake of the flux data and facilitates synergies between flux, remote sensing and modelling.

scholarly journals Carbon dioxide fluxes over an ancient broadleaved deciduous woodland in southern England

2011 ◽  
Vol 8 (6) ◽  
pp. 1595-1613 ◽  
Author(s):  
M. V. Thomas ◽  
Y. Malhi ◽  
K. M. Fenn ◽  
J. B. Fisher ◽  
M. D. Morecroft ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Primary Productivity ◽  
Management Practices ◽  
Net Primary Productivity ◽  
Deciduous Forest ◽  
Carbon Sink ◽  
Ecosystem Respiration ◽  
Flux Chamber ◽  
Southern England ◽  
Temperate Deciduous

Abstract. We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled net ecosystem exchange (NEE) data were partitioned into gross primary productivity (GPP) and ecosystem respiration (Re) and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated to be 21.1 Mg C ha−1 yr−1 and Re to be 19.8 Mg C ha−1 yr−1; net ecosystem productivity (NEP) was 1.2 Mg C ha−1 yr−1. These estimates were compared with independent bottom-up estimates derived from net primary productivity (NPP) and flux chamber measurements recorded at a plot within the flux footprint in 2008 (GPP = 26.5 ± 6.8 Mg C ha−1 yr−1, Re = 24.8 ± 6.8 Mg C ha−1 yr−1, biomass increment = ~1.7 Mg C ha−1 yr−1). Over the two years the difference in seasonal NEP was predominantly caused by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daily values of CO2 fluxes (R2 = 0.53 for the summer months for a linear regression), variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods supports the protection and management of temperate deciduous woodlands (including those managed for conservation rather than silvicultural objectives) as a strategy to mitigate atmospheric carbon dioxide increases.

scholarly journals Optimum Carrying Capacity for Bison in Theodore Roosevelt National Park

1983 ◽  
Vol 7 ◽  
pp. 89-92
Author(s):  
Clayton Marlow ◽  
Lynn Irby ◽  
Jack Norland
Keyword(s):  
Primary Productivity ◽  
Carrying Capacity ◽  
Food Habits ◽  
National Park ◽  
Net Primary Productivity ◽  
Theodore Roosevelt ◽  
Secondary Use ◽  
Theodore Roosevelt National Park ◽  
Management Priorities ◽  
Capacity Estimates

This project was designed to determine the optimum population size for bison in the Theodore Roosevelt National Park (TRNP) by fulfilling the following objectives: 1. Delineate primary and secondary areas of bison use. 2. Determine net primary productivity for major range sites within primary and secondary use areas. 3. Determine the general seasonal food habits of bison in TRNP. 4. Determine range trends under present population density of bison and the maximum carrying capacity of primary use areas. 5. Integrate range trend and carrying capacity estimates with management priorities for bison on the TRNP.

scholarly journals Partitioning of canopy and soil CO<sub>2</sub> fluxes in a pine forest at the dry timberline across a 13-year observation period

2020 ◽  
Vol 17 (3) ◽  
pp. 699-714
Author(s):  
Rafat Qubaja ◽  
Fyodor Tatarinov ◽  
Eyal Rotenberg ◽  
Dan Yakir
Keyword(s):  
Soil Respiration ◽  
Primary Productivity ◽  
Pinus Halepensis ◽  
Ecosystem Respiration ◽  
Carbon Accumulation ◽  
Dry Forest ◽  
Mean Annual Precipitation ◽  
Co2 Uptake ◽  
Belowground Carbon Allocation ◽  
Observation Period

Abstract. Partitioning carbon fluxes is key to understanding the process underlying ecosystem response to change. This study used soil and canopy fluxes with stable isotopes (13C) and radiocarbon (14C) measurements in an 18 km2, 50-year-old, dry (287 mm mean annual precipitation; nonirrigated) Pinus halepensis forest plantation in Israel to partition the net ecosystem's CO2 flux into gross primary productivity (GPP) and ecosystem respiration (Re) and (with the aid of isotopic measurements) soil respiration flux (Rs) into autotrophic (Rsa), heterotrophic (Rh), and inorganic (Ri) components. On an annual scale, GPP and Re were 655 and 488 g C m−2, respectively, with a net primary productivity (NPP) of 282 g C m−2 and carbon-use efficiency (CUE = NPP ∕ GPP) of 0.43. Rs made up 60 % of the Re and comprised 24±4 %Rsa, 23±4 %Rh, and 13±1 %Ri. The contribution of root and microbial respiration to Re increased during high productivity periods, and inorganic sources were more significant components when the soil water content was low. Comparing the ratio of the respiration components to Re of our mean 2016 values to those of 2003 (mean for 2001–2006) at the same site indicated a decrease in the autotrophic components (roots, foliage, and wood) by about −13 % and an increase in the heterotrophic component (Rh∕Re) by about +18 %, with similar trends for soil respiration (Rsa∕Rs decreasing by −19 % and Rh∕Rs increasing by +8 %, respectively). The soil respiration sensitivity to temperature (Q10) decreased across the same observation period by 36 % and 9 % in the wet and dry periods, respectively. Low rates of soil carbon loss combined with relatively high belowground carbon allocation (i.e., 38 % of canopy CO2 uptake) and low sensitivity to temperature help explain the high soil organic carbon accumulation and the relatively high ecosystem CUE of the dry forest.

scholarly journals Greenhouse gas emissions from rewetted bog peat extraction sites and a <i>Sphagnum</i> cultivation site in Northwest Germany

2014 ◽  
Vol 11 (3) ◽  
pp. 4493-4530 ◽  
Author(s):  
C. Beyer ◽  
H. Höper
Keyword(s):  
Water Level ◽  
Ecosystem Respiration ◽  
Net Ecosystem Exchange ◽  
Climate Impact ◽  
High Time Resolution ◽  
Climate Data ◽  
Climatic Effects ◽  
Northwest Germany ◽  
Below Ground ◽  
Cultivation Site

Abstract. During the last three decades, an increasing area of drained peatlands was rewetted. This was done with the objective to convert these sites from sources back to sinks or, at least, to much smaller sources of greenhouse gases (GHG). However, available data is still scarce, especially on the long-term climatic effects of rewetting of temperate bogs. Moreover, first field trials are established for Sphagnum cultivating (paludiculture) on wet bog sites and an assessment of the climate impact of such measures has not been studied yet. We conducted a field study on the exchange of carbon dioxide, methane and nitrous oxide at three rewetted sites with a gradient from dry to wet conditions and at a Sphagnum cultivation site in NW Germany over more than two years. Gas fluxes were measured using transparent and opaque closed chambers. The ecosystem respiration (CO2) and the net ecosystem exchange (CO2) were modelled in high time resolution using automatically monitored climate data. Measured and modelled values fit very well together (R2 between 0.88 and 0.98). Annually cumulated gas flux rates, net ecosystem carbon balances (NECB) and global warming potential (GWP) balances were determined. The annual net ecosystem exchange (CO2) varied strongly at the rewetted sites (from –201.7 ± 126.8 to 29.7 ± 112.7 g CO2-C m–2 a–1) due to different weather conditions, water level and vegetation. The Sphagnum cultivation site was a sink of CO2 (–118.8 ± 48.1 and −78.6 ± 39.8 g CO2-C m–2 a–1). The yearly CH4 balances ranged between 16.2 ± 2.2 and 24.2 ± 5.0 g CH4-C m–2 a–1 at two inundated sites, while one rewetted site with a comparatively low water level and the Sphagnum farming site show CH4 fluxes close to zero. The net N2O fluxes were low and not significantly different between the four sites. The annual NECB at the rewetted sites was between –183.8 ± 126.9 and 51.6 ± 112.8 g CO2-C m–2 a–1 and at the Sphagnum cultivating site –114.1 ± 48.1 and –75.3 ± 39.8 g CO2-C m–2 a–1. The yearly GWP100 balances ranged from –280.5 ± 465.2 to 644.5 ± 413.6 g CO2-eq. m–2 a–1 at the rewetted sites. In contrast, the Sphagnum farming site had a cooling impact on the climate in both years (–356.8 ± 176.5 and –234.9 ± 145.9 g CO2-C m–2 a–1). If the exported carbon through the harvest of the Sphagnum biomass and the additional CO2 emission from the decay of the organic material is considered, the NECB and GWP100 balances are near neutral. Peat mining sites are likely to become net carbon sinks and a peat accumulating ("growing") peatland within 30 years after rewetting, but the GWP100 balance may still be positive. A recommended measure for rewetting is to achieve a water level of a few centimetres below ground surface. Sphagnum farming is a climate friendly alternative to conventional commercial use of bogs. A year round constant water level of a few centimetres below ground level should be maintained.

scholarly journals Driving factors of temporary and permanent shallow lakes in and around Hwange National Park, Zimbabwe

Water SA ◽  
2018 ◽  
Vol 44 (2 April) ◽  
Author(s):  
Stembile Msiteli-Shumba ◽  
Shakki Kativu ◽  
Beaven Utete ◽  
Edwin Makuwe ◽  
Florence D Hulot
Keyword(s):  
Land Use ◽  
Water Level ◽  
Aquatic Ecosystems ◽  
National Park ◽  
Water Hardness ◽  
Dry Season ◽  
Driving Factors ◽  
Water Level Fluctuations ◽  
Arid Environments ◽  
Hwange National Park

Small aquatic ecosystems in semi-arid environments are characterised by strong seasonal water level fluctuations. In addition, land use as well as artificial pumping of groundwater to maintain water resources throughout the dry season may affect the functioning of aquatic ecosystems. In this study, we investigated pans situated in and around Hwange National Park, Zimbabwe, where certain waterholes are artificially maintained during the dry season for conservation purposes. We monitored 30 temporary and permanent waterholes for 7 months across the wet and dry seasons in 2013, and analysed them for standard parameters to investigate seasonal variations, assess the effects of land use and pumping on lake functioning, and determine the driving factors of these aquatic systems. Results show an increase in conductivity, hardness, and turbidity when temporary pans dry up and permanent ones are filled with groundwater. Prominent parameters explaining the diversity of aquatic ecosystems are water hardness, conductivity, turbidity, and the presence of vegetation. Seasonality differences in certain parameters suggest the influence of water level fluctuations associated with rainfall, evaporation, and pumping activities. Further, the distinction between turbid pans and those with clear water and vegetation suggests the alternative functioning of pans. Land use had no significant effects, while the effects of pumping are discussed. In times of water scarcity, animals gather around artificially maintained waterholes and foul water with faeces and urine, thus inducing water eutrophication.

Conservation status of Ramsar sites of Nepal Tarai: an overview

2010 ◽  
Vol 6 ◽  
pp. 76-84 ◽  
Author(s):  
Mohan Siwakoti ◽  
Jhamak B Karki
Keyword(s):  
Protected Areas ◽  
National Park ◽  
Management Practices ◽  
Hot Springs ◽  
Conservation Status ◽  
Buffer Zone ◽  
Freshwater Wetlands ◽  
Lake Area ◽  
The Status ◽  
Wildlife Reserve

Nepal houses only inland freshwater wetlands, ranging from floodplains of snow-melt-fed cold Himalayan rivers, warm rivers originating in the mid hills, high altitudinal glacial lakes to hot springs, ponds, ox-bow lakes, marshes and swamps. These wetlands support several endemic and globally threatened species of flora and fauna. Besides, wetland sites have significant recreational, religio-cultural and spiritual values. There are over 240 wetland sites in Nepal, of which 163 are in the Terai (plain lowland). Wetlands found in Tarai are comparatively more inventoried than the wetlands of mountains and the Himalayan regions of the country. The Terai region (below 300 m) covers about 14% of the country's total area, where half of Nepal's total populations exist. About 11% population of the country is wetland dependent; majority of them are living in the Terai region. The country has nine Ramsar sites, of which, four are in the Tarai region. Among them, two sites (Koshi Tappu wetland, and Beeshazar and associated lakes) lie inside the protected areas and two sites (Ghodaghodi Lake area and Jagadishpur Reservoir) are distributed outside the protected areas. The Koshi Tappu wetland lies along the floodplains of the Sapta Koshi River in the eastern Tarai within the Koshi Tappu Wildlife Reserve. It is the first Ramsar site in Nepal. Beeshazar and associated lakes lies in the buffer zone of the Chitwan National Park along the inner Tarai of Central Nepal. The Ghodaghodi Lake Area (2500 ha) lies in the far western Nepal, and comprises about 14 large and small ox-bow lakes/ponds with associated marshes, swamps, river/streams, springs, seasonal marshy grasslands and human made wetlands, out of them, Ghodaghodi Lake (138 ha) is the largest natural lake in the Nepal's Tarai. The lake system falls between the Bardia National Park and the Suklaphanta Wildlife Reserve of the country and  the surrounding forest functions as an important corridor for the movement of wildlife between these as well as the Tarai and the northern Siwalik hills. Similarly, the Jagadishpur Reservoir (225 ha) which lies in Central Nepal's Tarai is the largest man-made wetland in Nepal for irrigation purpose. It is an important site for migratory and resident birds. In this paper we highlight the status, threats, conservation issues and management practices of these Ramsar sites lying in Nepal Tarai. Key-words: Ghodaghodi Lake; Jagdishpur Reservoir; Nepal Tarai; outside protected area; wetlands.DOI: 10.3126/botor.v6i0.2914 Botanica Orientalis - Journal of Plant Science (2009) 6: 76-84

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