Changes in land use in the last two centuries in the Po lowlands (northern Italy)

2021 ◽  
Author(s):  
Matteo Meli ◽  
Luigi Bruno
Keyword(s):  
Land Use ◽  
Salt Marshes ◽  
Coastal Wetlands ◽  
Land Reclamation ◽  
Urban Expansion ◽  
Critical Role ◽  
Blue Carbon ◽  
Historical Maps ◽  
High Quality ◽  
Seagrass Meadows

<p>Changes in land use represent, after fossil-fuel combustion, the greatest cause of greenhouse-gases emission into the atmosphere. Coastal wetlands, also referred as coastal blue carbon ecosystems (e.g. salt marshes, mangrove forests, seagrass meadows, swamps), represent one of the most powerful C sinks among the Earth’s ecosystems, being capable to sequester organic carbon (OC) at rates ca. 30-50 times higher than terrestrial forests. Historically, land reclamation for agriculture, farming and urban expansion, severely impacted coastal wetlands, causing their loss and degradation. Wetlands drainage lead to the oxidation of organic matter previously stored under anaerobic conditions and the release of CO<sub>2</sub> into the atmosphere. Only recently the critical role of blue carbon ecosystems in climate-change mitigation has been recognised, highlighting the importance of protecting and studying these precious environments.</p><p>In this work, changes in land use in the last two centuries are reconstructed through comparison with historical maps. At the beginning of the 19<sup>th</sup> century Napoleon Bonaparte requested the development of high-quality maps of occupied territories. Among these, the so-called ‘Carta del Ferrarese’ (CdF), completed between 1812 and 1814, is composed of 38 sheets and represents, to a scale of 1:15.000, 240.000 hectares of the Po lowlands, roughly corresponding to the present-day Ferrara district. The CdF, archived at the Kriegsarchiv in Vienna, is an extraordinary example among historical maps for its high quality and accuracy, which constitute a two-centuries-old reliable paleo-landscape picture.</p><p>Within the Historical Land Use Change research project, leaded by the Emilia-Romagna Statistical and GIS Service, the CdF was scanned, accurately georeferenced and orthorectified, showing a surprising generalized match with recent maps. More than 31.000 polygons were digitized in a GIS environment and interpreted on the basis of the European Corine Land Cover codes, properly modified for the land uses at the time.</p><p>Comparison with the recent land use analysis, carried out in 2014, highlights changes in land use, mainly related to land reclamation. Salt marshes and swamps, originally extended for 100.000 hectares, were reduced of about 85%, starting from 1861. Major phases of land reclamation occurred in 1870s and 1960s. Geochemical analyses on shallow samples (depth < 50 cm), depict OC content of artificially drained soils < 5% of the total volume. Soil texture testifies to the almost complete mineralization of OC after reclamation. Only recently drained soils show higher OC content, in the range of 10-15%.</p>

scholarly journals Inorganic and black carbon hotspots constrain blue carbon mitigation services across tropical seagrass and temperate tidal marshes

2021 ◽  
Author(s):  
John Barry Gallagher ◽  
Vishnu Prahalad ◽  
John Aalders
Keyword(s):  
Salt Marsh ◽  
Organic Carbon ◽  
Salt Marshes ◽  
Inorganic Carbon ◽  
Blue Carbon ◽  
Tidal Marshes ◽  
Carbon Mitigation ◽  
Seagrass Meadows ◽  
First Time ◽  
Particulate Inorganic Carbon

Abstract Total organic carbon (TOC) sediment stocks as a CO2 mitigation service require exclusion of allochthonous black (BC) and particulate inorganic carbon corrected for water–atmospheric equilibrium (PICeq). For the first time, we address this bias for a temperate salt marsh and a coastal tropical seagrass in BC hotspots that represent two different blue carbon ecosystems of Malaysia and Australia. Seagrass TOC stocks were similar to the salt marshes with soil depths < 1 m (59.3 ± 11.3 and 74.9 ± 18.9 MgC ha− 1, CI 95% respectively). Both ecosystems showed larger BC constraints than their pristine counterparts did. However, the seagrass meadows’ mitigation services were largely constrained by both higher BC/TOC and PICeq/TOC fractions (38.0% ± 6.6% and 43.4% ± 5.9%, CI 95%) and salt marshes around a third (22% ± 10.2% and 6.0% ± 3.1% CI 95%). The results provide useful data from underrepresented regions, and, reiterates the need to consider both BC and PIC for more reliable blue carbon mitigation assessments.

scholarly journals Unraveling Latent Aspects of Urban Expansion: Desertification Risk Reveals More

2020 ◽  
Vol 17 (11) ◽  
pp. 4001
Author(s):  
Gianluca Egidi ◽  
Ilaria Zambon ◽  
Ilaria Tombolin ◽  
Luca Salvati ◽  
Sirio Cividino ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Quality ◽  
Land Use Planning ◽  
Urban Expansion ◽  
High Sensitivity ◽  
Sustainable Land Use ◽  
Land Use Patterns ◽  
High Quality ◽  
Regulatory Constraints ◽  
Desertification Risk

Urban expansion results in socioeconomic transformations with relevant impacts for peri-urban soils, leading to environmental concerns about land degradation and increased desertification risk in ecologically fragile districts. Spatial planning can help achieve sustainable land-use patterns and identify alternative locations for settlements and infrastructure. However, it is sometimes unable to comprehend and manage complex processes in metropolitan developments, fueling unregulated and mainly dispersed urban expansion on land with less stringent building constraints. Using the Mediterranean cities of Barcelona and Rome as examples of intense urbanization and ecological fragility, the present study investigated whether land use planning in these cities is (directly or indirectly) oriented towards conservation of soil quality and mitigation of desertification risk. Empirical results obtained using composite, geo-referenced indices of soil quality (SQI) and sensitivity to land desertification (SDI), integrated with high-resolution land zoning maps, indicated that land devoted to natural and semi-natural uses has lower soil quality in both contexts. The highest values of SDI, indicating high sensitivity to desertification, were observed in fringe areas with medium-high population density and settlement expansion. These findings reveal processes of land take involving buildable soils, sometimes of high quality, and surrounding landscapes in both cities. Overall, the results in this study can help inform land use planers and policymakers for conservation of high-quality soils, especially under weak (or partial) regulatory constraints.

scholarly journals Topographic Dependence of Cropland Transformation in China during the First Decade of the 21st Century

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yuejiao Li ◽  
Xiaohuan Yang ◽  
Wenli Long
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Land Reclamation ◽  
Southern China ◽  
Critical Role ◽  
Northern China ◽  
Limiting Factor ◽  
Spatial Statistical Analysis ◽  
Level Of Economic Development

Terrain plays a critical role in the selection of cropland. As a physical and geographical element of the landscape, terrain is an important limiting factor in land use change and has a strong influence on human activities. The objectives of this study are to investigate the topographic characteristics of cropland-related transformations in China during the first decade of the 21st century and to explore the implications of land use change as it relates to securing a national food supply. A 2010 satellite-based land use dataset and the DEM data were used to conduct spatial statistical analysis using altitude, slope, and fragmentation data. The results showed the following. (1) As the urbanization and industrialization of China occur, and China attempts to replace this occupied cropland with newly reclaimed cropland, the topography of the most recently reclaimed cropland has been more poorly suited to farming than the topography of the occupied cropland it replaces in most provinces. (2) The area of occupied cropland was much larger than of those reclaimed; the qualities of occupied and reclaimed cropland were significantly different. (3) Land reclamation mainly occurred in northern China, instead of in southern China, which has a higher level of economic development. Our findings imply that the potential area available for cropland production may be limited.

scholarly journals The blue carbon wealth of nations

2021 ◽  
Author(s):  
Christine Bertram ◽  
Martin Quaas ◽  
Thorsten B. H. Reusch ◽  
Athanasios T. Vafeidis ◽  
Claudia Wolff ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Salt Marshes ◽  
Economic Assessment ◽  
Blue Carbon ◽  
Coastal Ecosystem ◽  
Net Benefit ◽  
Seagrass Meadows ◽  
Ecosystem Carbon ◽  
Wealth Of Nations ◽  
And Storage

AbstractCarbon sequestration and storage in mangroves, salt marshes and seagrass meadows is an essential coastal ‘blue carbon’ ecosystem service for climate change mitigation. Here we offer a comprehensive, global and spatially explicit economic assessment of carbon sequestration and storage in three coastal ecosystem types at the global and national levels. We propose a new approach based on the country-specific social cost of carbon that allows us to calculate each country’s contribution to, and redistribution of, global blue carbon wealth. Globally, coastal ecosystems contribute a mean ± s.e.m. of US$190.67 ± 30 bn yr−1 to blue carbon wealth. The three countries generating the largest positive net blue wealth contribution for other countries are Australia, Indonesia and Cuba, with Australia alone generating a positive net benefit of US$22.8 ± 3.8 bn yr−1 for the rest of the world through coastal ecosystem carbon sequestration and storage in its territory.

The Counties District: land use trends and issues

1997 ◽  
pp. 5-8
Author(s):  
Murray Auld
Keyword(s):  
Land Use ◽  
Urban Expansion ◽  
Rural Environment ◽  
Land Resources ◽  
High Quality

The Counties District has traditionally been regarded as the food bowl of Auckland. Its high quality land resources, equitable climate and proximity to markets have and are still playing an important part in producing milk, vegetables and meat all year round. However, as Auckland continues to grow and people continue to want to live and pay to live in a rural environment the character and future of this food producing bowl is under threat. Keywords: Auckland, Counties District, land use, urban expansion

scholarly journals Vascular Plants Are Globally Significant Contributors to Marine Carbon Fluxes and Sinks

2020 ◽  
Vol 12 (1) ◽  
pp. 469-497 ◽  
Author(s):  
Simon M. Cragg ◽  
Daniel A. Friess ◽  
Lucy G. Gillis ◽  
Stacey M. Trevathan-Tackett ◽  
Oliver M. Terrett ◽  
...  
Keyword(s):  
Salt Marshes ◽  
Vascular Plants ◽  
Carbon Sink ◽  
Biomass Productivity ◽  
Carbon Fluxes ◽  
Blue Carbon ◽  
Glycoside Hydrolases ◽  
Polymer Complex ◽  
Mangrove Forests ◽  
Seagrass Meadows

More than two-thirds of global biomass consists of vascular plants. A portion of the detritus they generate is carried into the oceans from land and highly productive blue carbon ecosystems—salt marshes, mangrove forests, and seagrass meadows. This large detrital input receives scant attention in current models of the global carbon cycle, though for blue carbon ecosystems, increasingly well-constrained estimates of biomass, productivity, and carbon fluxes, reviewed in this article, are now available. We show that the fate of this detritus differs markedly from that of strictly marine origin, because the former contains lignocellulose—an energy-rich polymer complex of cellulose, hemicelluloses, and lignin that is resistant to enzymatic breakdown. This complex can be depolymerized for nutritional purposes by specialized marine prokaryotes, fungi, protists, and invertebrates using enzymes such as glycoside hydrolases and lytic polysaccharide monooxygenases to release sugar monomers. The lignin component, however, is less readily depolymerized, and detritus therefore becomes lignin enriched, particularly in anoxic sediments, and forms a major carbon sink in blue carbon ecosystems. Eventual lignin breakdown releases a wide variety of small molecules that may contribute significantly to the oceanic pool of recalcitrant dissolved organic carbon. Marine carbon fluxes and sinks dependent on lignocellulosic detritus are important ecosystem services that are vulnerable to human interventions. These services must be considered when protecting blue carbon ecosystems and planning initiatives aimed at mitigating anthropogenic carbon emissions.

scholarly journals Blue carbon stocks and exchanges along the California coast

2021 ◽  
Vol 18 (16) ◽  
pp. 4717-4732
Author(s):  
Melissa A. Ward ◽  
Tessa M. Hill ◽  
Chelsey Souza ◽  
Tessa Filipczyk ◽  
Aurora M. Ricart ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Carbon Sources ◽  
Carbon Stocks ◽  
Blue Carbon ◽  
California Coast ◽  
Seagrass Meadows ◽  
Terrestrial Habitats ◽  
Isotope Mixing Models ◽  
Sediment Carbon

Abstract. Salt marshes and seagrass meadows can sequester and store high quantities of organic carbon (OC) in their sediments relative to other marine and terrestrial habitats. Assessing carbon stocks, carbon sources, and the transfer of carbon between habitats within coastal seascapes are each integral in identifying the role of blue carbon habitats in coastal carbon cycling. Here, we quantified carbon stocks, sources, and exchanges in seagrass meadows, salt marshes, and unvegetated sediments in six bays along the California coast. In the top 20 cm of sediment, the salt marshes contained approximately twice as much OC as seagrass meadows did, 4.92 ± 0.36 kg OC m−2 compared to 2.20 ± 0.24 kg OC m−2, respectively. Both salt marsh and seagrass sediment carbon stocks were higher than previous estimates from this region but lower than global and US-wide averages, respectively. Seagrass-derived carbon was deposited annually into adjacent marshes during fall seagrass senescence. However, isotope mixing models estimate that negligible amounts of this seagrass material were ultimately buried in underlying sediment. Rather, the vast majority of OC in sediment across sites was likely derived from planktonic/benthic diatoms and/or C3 salt marsh plants.

scholarly journals Inorganic and black carbon hotspots constrain blue carbon mitigation services across tropical seagrass and temperate tidal marshes

2020 ◽  
Author(s):  
John Barry Gallagher ◽  
Vishnu Prahalad ◽  
John Aalders
Keyword(s):  
Salt Marsh ◽  
Organic Carbon ◽  
Salt Marshes ◽  
Inorganic Carbon ◽  
Blue Carbon ◽  
Tidal Marshes ◽  
Carbon Mitigation ◽  
Seagrass Meadows ◽  
First Time ◽  
Particulate Inorganic Carbon

AbstractTotal organic carbon (TOC) sediment stocks as a CO2 mitigation service requires exclusion of allochthonous black (BC) and particulate inorganic carbon corrected for water– atmospheric equilibrium (PICeq). For the first time, we address this bias for a temperate salt marsh and a coastal tropical seagrass in BC hotspots. Seagrass TOC stocks were similar to the salt marshes with soil depths < 1 m (59.3 ± 11.3 and 74.9 ± 18.9 MgC ha-1, CI 95% respectively) and sequestration rates of 1.134 MgC ha-1 yr-1. Both ecosystems showed larger BC constraints than their pristine counterparts. However, the seagrass meadows’ mitigation services were largely constrained by both higher BC/TOC and PICeq/TOC fractions (38.0% ± 6.6% and 43.4% ± 5.9%, CI 95%) and salt marshes around a third (22% ± 10.2% and 6.0% ± 3.1% CI 95%). The results demonstrate a need to account for both BC and PIC within blue carbon mitigation assessments.

scholarly journals Blue Carbon Stocks and Exchanges Along the Pacific West Coast

2021 ◽  
Author(s):  
Melissa A. Ward ◽  
Tessa M. Hill ◽  
Chelsey Souza ◽  
Tessa Filipczyk ◽  
Aurora M. Ricart ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Carbon Sources ◽  
Carbon Stocks ◽  
Blue Carbon ◽  
Seagrass Meadows ◽  
The Pacific ◽  
Terrestrial Habitats ◽  
Isotope Mixing Models ◽  
Sediment Carbon

Abstract. Salt marshes and seagrass meadows can sequester and store high quantities of organic carbon (OC) in their sediments relative to other marine and terrestrial habitats. Assessing carbon stocks, carbon sources, and the transfer of carbon between habitats within coastal seascapes are each integral in identifying the role of blue carbon habitats in coastal carbon cycling. Here, we quantified carbon stocks, sources, and exchanges in seagrass meadows, salt marshes, and unvegetated sediments in six bays along the Pacific coast of California. The salt marshes studied here contained approximately twice as much OC as did seagrass meadows, 23.51 ± 1.77 kg OC m−3 compared to 11.01 ± 1.18 kg OC m−3, respectively. Both seagrass and salt marsh sediment carbon stocks were higher than previous estimates from this region but lower than global and U.S.-wide averages, respectively. Seagrass-derived carbon was deposited annually into adjacent marshes during fall seagrass senescence. However, isotope mixing models estimate that negligible amounts of this seagrass material were ultimately buried in underlying sediment. Rather, the vast majority of OC in sediment across sites was likely derived from planktonic/benthic diatoms and C3 salt marsh plants.

scholarly journals Coastal Wetlands Effectively Sequester “Blue Carbon”

Eos ◽  
2017 ◽  
Author(s):  
Sarah Witman
Keyword(s):  
Carbon Storage ◽  
Salt Marshes ◽  
Coastal Wetlands ◽  
Blue Carbon ◽  
Seagrass Beds ◽  
Mangrove Forests

Mangrove forests, salt marshes, seagrass beds, and the like are carbon storage treasure troves.

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