The sensitivity of the carbon sink by coupled carbonate weathering to climate and land-use changes: Sediment records of the biological carbon pump effect in Fuxian Lake, Yunnan, China, during the past century

2020 ◽  
Vol 720 ◽  
pp. 137539 ◽  
Author(s):  
Haibo He ◽  
Zaihua Liu ◽  
Chongying Chen ◽  
Yu Wei ◽  
Qian Bao ◽  
...  
2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Madleina Gerecke ◽  
Oskar Hagen ◽  
Janine Bolliger ◽  
Anna M. Hersperger ◽  
Felix Kienast ◽  
...  

Abstract Landscapes have been changing at an increasing pace over the past century, with countless consequences for humans and their surrounding environments. Information on past and future land use change and the resulting alteration of landscape service provisioning are valuable inputs for policy making and planning. Land use transitions in Switzerland (2009–2081) were simulated using statistical models informed by past land use changes as well as environmental and socio-economic data (1979–2009). By combining land use types with additional contextual landscape information, eight landscape services, based on both (semi-)natural and artificial landscapes, were quantified and investigated on how they would evolve under projected land use changes. Investigation of land use transitions showed region-dependent trends of urban expansion, loss of agricultural area, and forest regrowth. Landscapes cannot accommodate all services simultaneously, and this study sheds light on some competing landscape services, in particular (i) housing at the expense of agriculture and (ii) vanishing recreation opportunities around cities as city limits, and thus housing and job provisioning, expand. Model projections made it possible to pinpoint potential trade-offs between landscape services in a spatially explicit manner, thereby providing information on service provision losses and supporting planning. While future changes are presented as extrapolations of the patterns quantified in the past, policy changes might cause deviation from the projections presented here. A major challenge is to produce socio-economic and policy scenarios to inform projections that will differ from current landscape management. Given that urban sprawl is affecting many land surfaces globally, the approach used here could be generalized to other countries in similar situations.


2005 ◽  
Vol 30 (4-5) ◽  
pp. 267-276 ◽  
Author(s):  
Min Tu ◽  
Michael J. Hall ◽  
Pieter J.M. de Laat ◽  
Marcel J.M. de Wit

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sibo Zeng ◽  
Zaihua Liu ◽  
Georg Kaufmann

AbstractThe response of carbonate weathering carbon-sink flux (CCSF) to its environmental drivers is still not well understood on the global scale. This hinders understanding of the terrestrial carbon cycle. Here, we show that there is likely to be a widespread and consistent increase in the global CCSF (ranging from + 9.8% (RCP4.5) to + 17.1% (RCP8.5)) over the period 1950–2100. In the coming years the increasing temperature might be expected to have a negative impact on carbonate weathering. However, the increasing rainfall and anticipated land-use changes will counteract this, leading to a greater CCSF. This finding has been obtained by using long-term historical (1950–2005) and modeled future (2006–2100) data for two scenarios (RCP4.5 and RCP8.5) for climate and land-use change in our CCSF equilibrium model. This study stresses the potential role that carbonate weathering may play in the evolution of the global carbon cycle over this century.


2018 ◽  
Vol 10 (10) ◽  
pp. 3421 ◽  
Author(s):  
Rahel Hamad ◽  
Heiko Balzter ◽  
Kamal Kolo

Multi-temporal Landsat images from Landsat 5 Thematic Mapper (TM) acquired in 1993, 1998, 2003 and 2008 and Landsat 8 Operational Land Imager (OLI) from 2017, are used for analysing and predicting the spatio-temporal distributions of land use/land cover (LULC) categories in the Halgurd-Sakran Core Zone (HSCZ) of the National Park in the Kurdistan region of Iraq. The aim of this article was to explore the LULC dynamics in the HSCZ to assess where LULC changes are expected to occur under two different business-as-usual (BAU) assumptions. Two scenarios have been assumed in the present study. The first scenario, addresses the BAU assumption to show what would happen if the past trend in 1993–1998–2003 has continued until 2023 under continuing the United Nations (UN) sanctions against Iraq and particularly Kurdistan region, which extended from 1990 to 2003. Whereas, the second scenario represents the BAU assumption to show what would happen if the past trend in 2003–2008–2017 has to continue until 2023, viz. after the end of UN sanctions. Future land use changes are simulated to the year 2023 using a Cellular Automata (CA)-Markov chain model under two different scenarios (Iraq under siege and Iraq after siege). Four LULC classes were classified from Landsat using Random Forest (RF). Their accuracy was evaluated using κ and overall accuracy. The CA-Markov chain method in TerrSet is applied based on the past trends of the land use changes from 1993 to 1998 for the first scenario and from 2003 to 2008 for the second scenario. Based on this model, predicted land use maps for the 2023 are generated. Changes between two BAU scenarios under two different conditions have been quantitatively as well as spatially analysed. Overall, the results suggest a trend towards stable and homogeneous areas in the next 6 years as shown in the second scenario. This situation will have positive implication on the park.


2020 ◽  
Vol 49 (1) ◽  
pp. 7-22
Author(s):  
LeRoy T. Hansen

Much of the research on ecosystem service values (ESVs) has limited applicability to USDA program benefit analyses, largely because the models/data/results (1) lack spatial breadth and hence cannot be applied in national analyses of USDA programs, and (2) do not link land use changes to the changes in ESs. This article provides an overview of a set of 15 ESVs related to agriculture's impacts on erosion in order to identify (1) weaknesses in methods, data, and assumptions that limit the quality of the ESVs and means of avoiding such weaknesses in future ESV development, and (2) approaches that might improve the reliability and spatial resolution of future ESV estimates.


2011 ◽  
Vol 7 ◽  
pp. 125-138 ◽  
Author(s):  
Beata Woziwoda ◽  
Dorota Michalska-Hejduk

The paper presents the changes of vascular plant flora in the Małków–Bartochów peatland area (the Warta River valley) which took place over a 40-year period. Vanishing, permanent and new components of the flora are presented with a special focus on valuable (protected by the law, threatened and locally rare) species. Changes in the share of ecological groups are estimated and discussed. Anthropogenic and natural factors, directly or indirectly influencing (in the past and at present) flora composition, are noted and analyzed.


In the Surface Water Acidification Project (SWAP) sediment profiles from five Scandinavian sites were analysed for 210 Pb by using refined isotope dilution alpha spectrometry. The 210 Pb parameters of these lakes were very similar to those obtained for protected forest lakes with no land-use activities. These data demonstrated almost exclusive atmospheric inputs and an internal deposition regulated by the organic fractionation and the grain-size distribution in the sediments. Preliminary speciation experiments showed minor losses of 210 (≤ 5%) through enhanced dissolution of fulvic compounds at acid conditions (pH ≥ 4). The sediment accumulation rates (constant rate of unsupported 210 Pb supply (CRS) model) of the lakes gradually increased, by at least a factor of three, over the past century although 210 Pb parameters did not show any strong signs of enhanced land-use activities. This is perhaps caused by more efficient preservation of the sediments through humic precipitation under more acid conditions.


2014 ◽  
Vol 14 (19) ◽  
pp. 26297-26348
Author(s):  
S. D. D'Andrea ◽  
J. C. Acosta Navarro ◽  
S. C. Farina ◽  
C. E. Scott ◽  
A. Rap ◽  
...  

Abstract. Emissions of biogenic volatile organic compounds (BVOC) have changed in the past millennium due to changes in land use, temperature and CO2 concentrations. Recent model reconstructions of BVOC emissions over the past millennium predicted changes in dominant secondary organic aerosol (SOA) producing BVOC classes (isoprene, monoterpenes and sesquiterpenes). The reconstructions predicted that global isoprene emissions have decreased (land-use changes to crop/grazing land dominate the reduction), while monoterpene and sesquiterpene emissions have increased (temperature increases dominate the increases); however, all three show regional variability due to competition between the various influencing factors. These BVOC changes have largely been anthropogenic in nature, and land-use change was shown to have the most dramatic effect by decreasing isoprene emissions. In this work, we use two modeled estimates of BVOC emissions from the years 1000 to 2000 to test the effect of anthropogenic changes to BVOC emissions on SOA formation, global aerosol size distributions, and radiative effects using the GEOS-Chem-TOMAS global aerosol microphysics model. With anthropogenic emissions (e.g. SO2, NOx, primary aerosols) held at present day values and BVOC emissions changed from year 1000 to year 2000 values, decreases in the number concentration of particles of size Dp > 80 nm (N80) of >25% in year 2000 relative to year 1000 were predicted in regions with extensive land-use changes since year 1000 which led to regional increases in direct plus indirect aerosol radiative effect of >0.5 W m−2 in these regions. We test the sensitivity of our results to BVOC emissions inventory, SOA yields and the presence of anthropogenic emissions; however, the qualitative response of the model to historic BVOC changes remains the same in all cases. Accounting for these uncertainties, we estimate millennial changes in BVOC emissions cause a global mean direct effect of between +0.022 and +0.163 W m−2 and the global mean cloud-albedo aerosol indirect effect of between −0.008 and −0.056 W m−2. This change in aerosols, and the associated radiative forcing, could be a~largely overlooked and important anthropogenic aerosol effect on regional climates.


2013 ◽  
Vol 4 (1) ◽  
pp. 507-539 ◽  
Author(s):  
Q. Zhang ◽  
A. J. Pitman ◽  
Y. P. Wang ◽  
Y. Dai ◽  
P. J. Lawrence

Abstract. We examine the impact of land use and land cover change (LULCC) over the period from 1850 to 2005 using an Earth System Model that incorporates nitrogen and phosphorous limitation on the terrestrial carbon cycle. We compare the estimated CO2 emissions and warming from land use change in a carbon only version of the model with those from simulations including nitrogen and phosphorous limitation. If we omit nutrients, our results suggest LULCC cools on the global average by about 0.1 °C. Including nutrients reduces this cooling to ~ 0.05 °C. Our results also suggest LULCC has a major impact on total land carbon over the period 1850–2005. In carbon only simulations, the inclusion of LULCC decreases the total additional land carbon stored in 2005 from around 210 Pg C to 85 Pg C. Including nitrogen and phosphorous limitation also decreases the scale of the terrestrial carbon sink to 80 Pg C. In particular, adding LULCC on top of the nutrient limited simulations changes the sign of the terrestrial carbon flux from a sink to a source (12 Pg C). The CO2 emission from LULCC from 1850 to 2005 is estimated to be 130 Pg C for carbon only simulation, or 97 Pg C if nutrient limitation is accounted for in our model. The difference between these two estimates of CO2 emissions from LULCC largely results from the weaker response of photosynthesis to increased CO2 and smaller carbon pool sizes, and therefore lower carbon loss from plant and wood product carbon pools under nutrient limitation. We suggest that nutrient limitation should be accounted in simulating the effects of LULCC on the past climate and on the past and future carbon budget.


2017 ◽  
Vol 18 (4) ◽  
pp. 211
Author(s):  
Rani Yudarwati ◽  
Santun R.P Sitorus ◽  
Khursatul Munibah

Controlling the rate of land use change is necessary due to maintaining environment sustainability.  One of the efforts is studying the changes that occur in the past few years. These changes can be studied by Markov - Cellular Automata model.Cianjur is one of the regency that has a high risk of landslide hazard, so it is necessary to control land use change in order to realize environmental sustainability in accordance with the spatial plan of Cianjur regency (RTRW). The purpose of this study was to see land use changes that occurred and evaluated with the spatial plan (RTRW) and also to conduct controlling scenarios of land use changes. The analysis showed that Cianjur regency has drastically decreased in forest area up to 10,3% and landuse inconsistencyof 10,4%. The prediction results showed that landuse change without intervention would dramatically increase inconsistency up to 20,5%. Land use scenario of restoring forest could reduce inconsistency up to 16,6%.


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