scholarly journals Holocene land-cover reconstructions for studies on land cover-climate feedbacks

2010 ◽  
Vol 6 (4) ◽  
pp. 483-499 ◽  
Author(s):  
M.-J. Gaillard ◽  
S. Sugita ◽  
F. Mazier ◽  
A.-K. Trondman ◽  
A. Broström ◽  
...  
Keyword(s):  
Land Cover ◽  
Agricultural Land ◽  
Time Windows ◽  
Regional Climate ◽  
Traditional Use ◽  
The Holocene ◽  
Human Land Use ◽  
The Impact ◽  
Reveals Model

Abstract. The major objectives of this paper are: (1) to review the pros and cons of the scenarios of past anthropogenic land cover change (ALCC) developed during the last ten years, (2) to discuss issues related to pollen-based reconstruction of the past land-cover and introduce a new method, REVEALS (Regional Estimates of VEgetation Abundance from Large Sites), to infer long-term records of past land-cover from pollen data, (3) to present a new project (LANDCLIM: LAND cover – CLIMate interactions in NW Europe during the Holocene) currently underway, and show preliminary results of REVEALS reconstructions of the regional land-cover in the Czech Republic for five selected time windows of the Holocene, and (4) to discuss the implications and future directions in climate and vegetation/land-cover modeling, and in the assessment of the effects of human-induced changes in land-cover on the regional climate through altered feedbacks. The existing ALCC scenarios show large discrepancies between them, and few cover time periods older than AD 800. When these scenarios are used to assess the impact of human land-use on climate, contrasting results are obtained. It emphasizes the need for methods such as the REVEALS model-based land-cover reconstructions. They might help to fine-tune descriptions of past land-cover and lead to a better understanding of how long-term changes in ALCC might have influenced climate. The REVEALS model is demonstrated to provide better estimates of the regional vegetation/land-cover changes than the traditional use of pollen percentages. This will achieve a robust assessment of land cover at regional- to continental-spatial scale throughout the Holocene. We present maps of REVEALS estimates for the percentage cover of 10 plant functional types (PFTs) at 200 BP and 6000 BP, and of the two open-land PFTs "grassland" and "agricultural land" at five time-windows from 6000 BP to recent time. The LANDCLIM results are expected to provide crucial data to reassess ALCC estimates for a better understanding of the land suface-atmosphere interactions.

scholarly journals Holocene land-cover reconstructions for studies on land cover-climate feedbacks

2010 ◽  
Vol 6 (2) ◽  
pp. 307-346 ◽  
Author(s):  
M.-J. Gaillard ◽  
S. Sugita ◽  
F. Mazier ◽  
J. O. Kaplan ◽  
A.-K. Trondman ◽  
...  
Keyword(s):  
Land Cover ◽  
Agricultural Land ◽  
Time Windows ◽  
Regional Climate ◽  
Traditional Use ◽  
The Holocene ◽  
Human Land Use ◽  
The Impact ◽  
Reveals Model

Abstract. The major objectives of this paper are: (1) to review the pros and cons of the scenarios of past anthropogenic land cover change (ALCC) developed during the last ten years, (2) to discuss issues related to pollen-based reconstruction of the past land-cover and introduce a new method, REVEALS (Regional Estimates of VEgetation Abundance from Large Sites), to infer long-term records of past land-cover from pollen data, (3) to present a new project (LANDCLIM: LAND cover – CLIMate interactions in NW Europe during the Holocene) currently underway, and show preliminary results of REVEALS reconstructions of the regional land-cover in the Czech Republic for five selected time windows of the Holocene, and (4) to discuss the implications and future directions in climate and vegetation/land-cover modeling, and in the assessment of the effects of human-induced changes in land-cover on the regional climate through altered feedbacks. The existing ALCC scenarios show large discrepancies between them, and few cover time periods older than AD 800. When these scenarios are used to assess the impact of human land-use on climate, contrasting results are obtained. It emphasizes the need of REVEALS model-based land-cover reconstructions. They might help to fine-tune descriptions of past land-cover and lead to a better understanding of how long-term changes in ALCC might have influenced climate. The REVEALS model is proved to provide better estimates of the regional vegetation/land-cover changes than the traditional use of pollen percentages. Thus, the application of REVEALS opens up the possibility of achieving a more robust assessment of land cover at regional- to continental-spatial scale throughout the Holocene. We present maps of REVEALS estimates for the percentage cover of 10 plant functional types (PFTs) at 200 BP and 6000 BP, and of the two open-land PFTs "grassland" and "agricultural land" at five time-windows from 6000 BP to recent time. The LANDCLIM results are expected to provide crucial data to reassess ALCC estimates for a better understanding of the land suface-atmosphere interactions.

scholarly journals Spatiotemporal changes to low flow and catchment storage following a step change rainfall decline in Southwest Western Australia

2020 ◽  
Author(s):  
Keith Smettem ◽  
Ning Liu ◽  
Richard Harper ◽  
John Ruprecht
Keyword(s):  
Land Cover ◽  
Western Australia ◽  
Agricultural Land ◽  
Low Flow ◽  
Deep Soil ◽  
Low Flows ◽  
Eucalyptus Forest ◽  
Flow Duration Curves ◽  
The Impact

<p>Understanding how summer low flows in a Mediterranean climate are influenced by climate and land use is critical for managing both water resources and in-stream ecohydrological health. The Eucalyptus forest ecosystems of southwestern Australia are experiencing a drying and warming climate, with a regional step decline in rainfall in the mid-1970s.  Reductions in catchment water storage may be exacerbated by the deep rooting habit of key overstorey species (>30 m has been reported), which can buffer against drought during dry years. Root exploitation of deep soil moisture reserves and/or groundwater can accelerate the long term decline in summer low flows, with a trend towards more ephemeral flow regimes. In contrast, conversion of forests to agricultural land in some catchments can lead to counter-trends of increased low flows due to a rise in groundwater pressure.  These are invariably associated with an increase in stream salinity as regolith stores of salt are mobilized. There has also been extennsive reforestation of farmland in some catchments. </p><p>In this study we perform a detailed analysis of changes to annual summer seven day low flow trends in perennial catchments and flow duration curves in ephemeral catchments across 39 catchments in south-western Australia that have long term records of runoff, rainfall and land cover.  Results showed that 15% of catchments exhibited increased low flows and 85% decreased flows or decreased flow days since the 1970s.  Significant downward step changes in low flows were observed in 17 catchments (44%). The earliest downward step changes occurred in three catchments between 1981-82 (a lag of one decade after the rainfall decline), with the most recent step changes for five catchments occurring in 2001-2004 (three decades after rainfall decline).  Eleven catchments were already ephemeral in the 1970s, but exhibited continued declines in the number of annual flow days over subsequent decades.  Step changes occur when groundwater becomes disconnected or reconnected to the stream invert, with disconnection associated with rainfall decline and vegetative water use.  </p><p>The statistical methods we used in this study can be applied to any catchment in order to aid land and water managers assess the impact of climate change and land cover manipulation on low flow response.</p>

Modelling long-term soil organic carbon dynamics under the impact of land cover change and soil redistribution

CATENA ◽  
2017 ◽  
Vol 151 ◽  
pp. 63-73 ◽  
Author(s):  
Samuel Bouchoms ◽  
Zhengang Wang ◽  
Veerle Vanacker ◽  
Sebastian Doetterl ◽  
Kristof Van Oost
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Land Cover ◽  
Land Cover Change ◽  
Carbon Dynamics ◽  
Soil Redistribution ◽  
The Impact ◽  
Soil Organic Carbon Dynamics

scholarly journals Climate Change Controls Phosphorus Transport from the Watershed into Lake Kinneret (Israel)

2021 ◽  
Author(s):  
Moshe Gophen
Keyword(s):  
Climate Change ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Lake Kinneret ◽  
Phosphorus Transport ◽  
Efficient Management ◽  
Hula Valley ◽  
Reclamation Project ◽  
The Impact

AbstractPart of the Kinneret watershed, the Hula Valley, was modified from wetlands – shallow lake for agricultural cultivation. Enhancement of nutrient fluxes into Lake Kinneret was predicted. Therefore, a reclamation project was implemented and eco-tourism partly replaced agriculture. Since the mid-1980s, regional climate change has been documented. Statistical evaluation of long-term records of TP (Total Phosphorus) concentrations in headwaters and potential resources in the Hula Valley was carried out to identify efficient management design targets. Significant correlation between major headwater river discharge and TP concentration was indicated, whilst the impact of external fertilizer loads and 50,000 winter migratory cranes was probably negligible. Nevertheless, confirmed severe bdamage to agricultural crops carried out by cranes led to their maximal deportation and optimization of their feeding policy. Consequently, the continuation of the present management is recommended.

Generating long-term high-resolution land-use change datasets for regional climate modeling in CORDEX domains

2021 ◽  
Author(s):  
Peter Hoffmann ◽  
Diana Rechid ◽  
Vanessa Reinhart ◽  
Christina Asmus ◽  
Edouard L. Davin ◽  
...  
Keyword(s):  
Land Use ◽  
High Resolution ◽  
Land Use Change ◽  
Land Cover ◽  
Climate Modeling ◽  
Regional Climate ◽  
Regional Climate Modeling ◽  
Local Scale ◽  
Modeling Studies

<p>Land-use and land cover (LULC) are continuously changing due to environmental changes and anthropogenic activities. Many observational and modeling studies show that LULC changes are important drivers altering land surface feedbacks and land-atmosphere exchange processes that have substantial impact on climate on the regional and local scale. Yet, most long-term regional climate modeling studies do not account for these changes. Therefore, within the WCRP CORDEX Flagship Pilot Study LUCAS (Land Use Change Across Scales) a new workflow was developed to generate high-resolution annual land cover change time series based on past reconstructions and future projections. First, the high-resolution global land cover dataset ESA-CCI LC (~300 m resolution) is aggregated and converted to a 0.1° resolution, fractional plant functional type (PFT) dataset. Second, the land use change information from the land-use harmonized dataset (LUH2), provided at 0.25° resolution as input for CMIP6 experiments, is translated into PFT changes employing a newly developed land use translator (LUT). The new LUT was first applied to the EURO-CORDEX domain. The resulting LULC maps for past and future - the LUCAS LUC dataset - can be applied as land use forcing to the next generation RCM simulations for downscaling CMIP6 by the EURO-CORDEX community and in the framework of FPS LUCAS. The dataset includes land cover and land management practices changes important for the regional and local scale such as urbanization and irrigation. The LUCAS LUC workflow is applied to further CORDEX domains, such as Australasia and North America. The resulting past and future land cover changes will be presented, and challenges regarding the application of the new workflow to different regions will be addressed. In addition, issues related to the implementation of the dataset into different RCMs will be discussed.</p>

Short-term Land Acquisition, Long-term Impacts: The Case of Houbara Bustard Hunting in South Punjab, Pakistan

2019 ◽  
Vol 54 (3) ◽  
pp. 390-408
Author(s):  
Salman Ata ◽  
Babar Shahbaz ◽  
Muhammad Arif Watto ◽  
Muhammad Tahir Siddiqui
Keyword(s):  
Evaluation System ◽  
Agricultural Land ◽  
Local Population ◽  
Land Acquisition ◽  
Limited Area ◽  
Sustainable Livelihood ◽  
Hunting Season ◽  
Houbara Bustard ◽  
The Impact

Pakistan provides seasonal hunting permits to the rulers of Gulf countries for hunting of Asian Houbara bustard ( Chlamydotis macqueenii) in different parts of the country. This research deals with (transnational) seasonal land acquisition of different rangelands/deserts of the Punjab province of Pakistan. So far, no comprehensive research has been conducted in Pakistan on this issue. This research attempts to address the impact of seasonal land grabbing by the foreigners on livelihood assets of local stakeholders in South Punjab, Pakistan. Based on the idea of ‘control grabbing’, this research uses ‘sustainable livelihood framework’ as an analytical framework. Quantitative and qualitative data were acquired from three (out of a total nine) randomly selected hunting sanctuaries in the districts of Rajanpur and Dera Ghazi Khan. The results revealed that natural assets of local population (agricultural land and rangeland) are adversely affected during the entire hunting season. Limited access to natural assets (especially livestock fodder) has long-term negative impacts on livelihood diversification of the locals as the number of livestock – one of the most important assets of respondents – is continuously decreasing in the case study area. We recommend that land enclosure should be restricted to a limited area for a limited time, and that the Government should develop an effective monitoring and evaluation system.

Habitat mapping and change assessment of coastal wetlands by using Sentinel-2 time series and ecological expert knowledge

2020 ◽  
Author(s):  
Maria Adamo ◽  
Valeria Tomaselli ◽  
Francesca Mantino ◽  
Cristina Tarantino ◽  
Palma Blonda
Keyword(s):  
Time Series ◽  
Land Cover ◽  
Coastal Wetlands ◽  
Expert Knowledge ◽  
Land Reclamation ◽  
Habitat Mapping ◽  
The Mediterranean ◽  
The Impact ◽  
Sentinel 2

<p>Coastal wetlands are one of the most threatened ecosystems worldwide. In the Mediterranean Region, wetlands are undergoing rapid changes due to the increasing of human pressures (e.g. land reclamation, water resources exploitation) and climate changes (e.g. coastal erosion), with a resulting habitat degradation, fragmentation, and biodiversity loss.</p><p>Long-term habitat mapping and change detection are essential for the management of coastal wetlands as well as for evaluating the impact of conservation policies.</p><p>Earth observation (EO) data and techniques are a valuable resource for long-term habitat mapping, thanks to the large amount of available data and their high spatial and temporal resolution. In this study, we propose an approach based on the integration of time series of Sentinel-2 images and ecological expert knowledge for land cover (LC) mapping and automatic translation to habitats in coastal wetlands. In particular, the research relies on the exploitation of ecological rules based on combined information related to plant phenology, water seasonality of aquatic species, pattern zonation, and habitat geometric properties.</p><p>The methodology is applied to two Natura2000 sites, “Zone umide della Capitanata” and “Paludi presso il Golfo di Manfredonia”, located in the northeastern part of the Puglia region. These two areas are the most extensive wetlands of the Italian peninsula and the largest components of the Mediterranean wetland system.</p><p>Land Cover classes are labelled according to the FAO-LCCS taxonomy, which offers a framework to integrate EO data with in situ and ancillary data. Output habitat classes are labelled according to EUNIS habitat classification.</p>

Unmixing the regional climate response to recent historical land cover changes in Europe

2020 ◽  
Author(s):  
Bo Huang ◽  
Xiangping Hu ◽  
Geir-Arne Fuglstad ◽  
Xu Zhou ◽  
Wenwu Zhao ◽  
...  
Keyword(s):  
Land Cover ◽  
Large Scale ◽  
Agricultural Land ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Energy Budget ◽  
Land Cover Changes ◽  
Climate Response ◽  
Statistical Regression ◽  
Cooling Effects

<p>Land cover changes (LCCs) influence the regional climate because they alter biophysical mechanisms like evapotranspiration, albedo, and surface roughness. Previous research mainly assessed the regional climate implications of individual land cover transitions, such as the effects of historical forest clearance or idealized large-scale scenarios of deforestation/afforestation, but the combined effects from the mix of recent historical land cover changes in Europe have not been explored. In this study, we use a combination of high resolution land cover data with a regional climate model (the Weather Research and Forecasting model, WRF, v3.9.1) to quantify the effects on surface temperature of land cover changes between 1992 and 2015. Unlike many previous studies that had to use one unrealistic large-scale simulation for each LCC to single out its climate effects, our analysis simultaneously considers the effects of the mix of historical land cover changes in Europe and introduces a new method to disentangle the individual contributions. This approach, based on a ridge statistical regression, does not require an explicit consideration of the different components of the surface energy budget, and directly shows the temperature changes from each land transition.</p><p>            From 1992 to 2015, around 70 Mha of land transitions occurred in Europe. Approximately 25 Mha of agricultural land was left abandoned, which was only partially compensated by cropland expansion (about 20 Mha). Declines in agricultural land mostly occurred in favor of forests (15 Mha) and urban settlements (8 Mha). Relative to 1992, we find that the land covers of 2015 are associated with an average temperature cooling of -0.12±0.20 °C, with seasonal and spatial variations. At a continental level, the mean cooling is mainly driven by agriculture abandonment (cropland-to-forest transitions). Idealized simulations where cropland transitions to other land classes are excluded result in a mean warming of +0.10±0.19 °C, especially during summer. Conversions to urban land always resulted in warming effects, whereas the local temperature response to forest gains and losses shows opposite signs from the western and central part of the domain (where forests have cooling effects) to the eastern part (where forests are associated to warming). Gradients in soil moisture and local climate conditions are the main drivers of these differences. Our findings are a first attempt to quantify the regional climate response to historical LCC in Europe, and our method allows to unmix the temperature signal of a grid cell to the underlying LCCs (i.e., temperature impact per land transition). Further developing biophysical implications from LCCs for their ultimate consideration in land use planning can improve synergies for climate change adaptation and mitigation.</p><p> </p>

The Impact of Aerosols on the Summer Rainfall Frequency in China

2008 ◽  
Vol 47 (6) ◽  
pp. 1802-1813 ◽  
Author(s):  
Yong-Sang Choi ◽  
Chang-Hoi Ho ◽  
Jinwon Kim ◽  
Dao-Yi Gong ◽  
Rokjin J. Park
Keyword(s):  
Regional Climate ◽  
Cloud Amount ◽  
Summer Rainfall ◽  
Aerosol Concentration ◽  
Short Term ◽  
Cloud Optical Depth ◽  
Cloud Properties ◽  
Rainfall Frequency ◽  
The Impact

Abstract The authors investigate the short-term relationship between aerosol concentrations and summer rainfall frequency in China using the daily surface observations of particulate matters with a diameter of less than 10 μm (PM10) mass concentration, rainfall, and satellite-observed cloud properties. Results in this study reveal that on the time scale of a few days aerosol concentration is positively correlated with the frequency of moderate-rainfall (10–20 mm day−1) days but is negatively correlated with the frequency of light-rainfall (<5 mm day−1) days. Satellite observations of cloud properties show that higher aerosol concentrations are positively correlated with the increase in mixed cloud amount, cloud effective radius, cloud optical depth, and cloud-top heights; this corresponds to the decrease in low-level liquid clouds and the increase in midlevel ice–mixed clouds. Based on this analysis, the authors hypothesize that the increase in aerosol concentration results in the increase in summer rainfall frequency in China via enhanced ice nucleation in the midtroposphere. However, over the past few decades, observations show an increasing long-term trend in aerosol concentration but decreasing trends in summer rainfall frequency and relative humidity (RH) in China. Despite the short-term positive relationship between summer rainfall frequency and aerosol concentration found in this study, the long-term variations in summer rainfall frequency in China are mainly determined by other factors including RH variation possibly caused by global and regional climate changes. A continuous decrease in RH resulting in less summer rainfall frequency may further enhance aerosol concentrations in the future in conjunction with the increase in the anthropogenic emissions.

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