CO2 and land-use effects on Australian vegetation over the last two centuries

2002 ◽  
Vol 50 (4) ◽  
pp. 511 ◽  
Author(s):  
Sandra L. Berry ◽  
Michael L. Roderick
Keyword(s):  
Land Use ◽  
Vegetation Cover ◽  
Natural Vegetation ◽  
Perennial Grasses ◽  
Continental Scale ◽  
European Settlement ◽  
Two Factors ◽  
Land Use Effects ◽  
Carbon Dioxide Co2 ◽  
Land Use And Management

Coincident with major changes in land use and management in Australia over the past 200 years, there has been a 20% increase in the concentration of carbon dioxide ([CO2]) in the atmosphere. We investigate the way in which these two factors have modified the natural vegetation at the continental scale. We describe landscapes in terms of the abundance of three leaf functional types, 'turgor' (T), 'mesic' (M) and 'sclerophyll' (S). We have previously shown that continental-scale estimates of the TMS composition can be made from climatic and satellite data. In this study, we extend those results by estimating the TMS composition for the 'natural' vegetation (i.e. the present vegetation if there had been no change in land use and management). By comparing those estimates with the existing vegetation, we show that changes in land use have resulted in a large increase in the abundance of T leaves (seasonally green leaves of annual and ephemeral herbaceous plants) and there is a corresponding decline in plants with M and S leaves (evergreen trees, shrubs and perennial grasses). We then use a water use efficiency model to estimate the natural vegetation cover 200 years ago when the [CO2] was about 280 μmol mol–1. According to the model, 200 years ago the seasonally green (T) vegetation cover was similar to that at the present (excluding cultural vegetation cover), but there was lower evergreen cover. The increase in evergreen cover with increasing [CO2] could have been expressed as an increase in trees, shrubs or grasses having M and S leaf forms, depending on soil moisture and nutrient availability. According to our model, while 'woody vegetation thickening' may have been exacerbated by the increase in [CO2], other changes associated with European settlement are also important.

The impact of recent land-use change in the Araucaria araucana forest in northern Patagonia

The Holocene ◽  
2020 ◽  
Vol 30 (8) ◽  
pp. 1101-1114 ◽  
Author(s):  
Ricardo Moreno-Gonzalez ◽  
Thomas Giesecke ◽  
Sonia L Fontana
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Vegetation Cover ◽  
Natural Vegetation ◽  
Northern Patagonia ◽  
Rumex Acetosella ◽  
Araucaria Araucana ◽  
The 1950S ◽  
The Impact ◽  
Nothofagus Dombeyi

Land-use change in the form of extensive Pinus plantations is currently altering the natural vegetation cover at the forest–steppe ecotone in northern Patagonia. Providing recommendations for conservation efforts, with respect to this recent and earlier land-use changes, requires a longer time perspective. Using pollen analysis, we investigated to what degree the colonization of the area by Euro-American settlers changed the forest composition and the vegetation cover, and to explore the spread of the European weed Rumex acetosella. This study is based on short sediment cores from six lakes in the Araucaria araucana forest region, across the vegetation gradient from the forest to the steppe. Results document that although Araucaria araucana has been extensively logged elsewhere, near the investigated sites, populations were rather stable and other elements of the vegetation changed little with the initiation of Euro-American settlements. A reduction of Nothofagus dombeyi-type pollen occurred at some sites presumably due to logging Nothofagus dombeyi trees, while toward the steppe, Nothofagus antarctica shrubs may have been removed for pasture. The appearance of Rumex acetosella pollen is consistent with the initiation of land use by Euro-American settlers in all cores, probably indicating the onset of animal farming. The rise of the Rumex acetosella pollen curve during the 1950s marks more recent land-use change. These observations indicate that the spread and local expansion of the weed requires disturbance. Overall, the study shows that the initial colonization of the area by Euro-American settlers had little effect on the natural vegetation structure, while developments since the 1950s are strongly altering the natural vegetation cover.

scholarly journals Farming expansion and land degradation in Western Bahia, Brazil

2009 ◽  
Vol 9 (3) ◽  
pp. 61-76 ◽  
Author(s):  
Mateus Batistella ◽  
Gustavo Souza Valladares
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Land Degradation ◽  
Land Use Planning ◽  
Water Conservation ◽  
Vegetation Cover ◽  
Temporal Dynamics ◽  
Natural Vegetation ◽  
Northeastern Brazil ◽  
Temporal And Spatial Distribution

Land degradation by soil erosion has called attention in tropical developing countries, particularly when natural vegetation is converted to farmland. Thus, the occupation of Brazilian savannas in Western Bahia is a matter of growing environmental concern. There are approximately 10 million hectares affected by this relatively recent land-use dynamics, but little is known about the temporal and spatial distribution of the process. To better understand such transformations, this paper addresses three related topics: land use/land cover (LULC) in 1985 and 2000; LULC dynamics between 1985 and 2000; and risk of land degradation by soil erosion as a function of farming expansion. The study area is located in Northeastern Brazil, between the coordinates 11º S and 46º 30' W and 14º S and 43º 30' W. All classes of natural vegetation cover decreased their areas during the period of study. Savanna (cerrado) lost 21.0% of its original area. Modern farming and irrigated areas increased 154.4 and 526.0%, respectively. Farming expansion reached 1,675,233 ha. Moderate risk of land degradation by soil erosion increased from 28.0 to 36.8% of the landscape mosaic between 1985 and 2000. The spatial and temporal dynamics observed reproduces development and land degradation examples of other savanna lands in Brazil. The integrity of native vegetation cover and the dissemination of soil and water conservation practices should be considered. This research contributes with an understanding of landscape transformations as a baseline for strategic environmental and land-use planning within the region.

A climate-soil-vegetation-human interaction analysis for SOC change monitoring over 30 years across the National Ecological Observatory Network, USA

2021 ◽  
Author(s):  
Jie Hu ◽  
Jingyi Huang ◽  
Alfred Hartemink ◽  
Ankur Desai
Keyword(s):  
Land Use ◽  
Human Disturbance ◽  
Structural Equation Models ◽  
Interaction Analysis ◽  
Natural Vegetation ◽  
Human Interaction ◽  
Eastern Coast ◽  
Continuous Change ◽  
Continental Scale ◽  
Time Substitution

<p>Previous studies of long-term soil change have been focusing on the impacts of climate and land-use change, while neglecting the impacts of soil taxonomy on soil’s response to vegetational and human disturbance. In this study, a spatial-temporal framework was used to study the change in soil organic carbon (SOC) across National Ecological Observatory Network (NEON), USA over 30 years. We hypothesize that: 1) on the continental scale, the hot-spots and cold-spots of SOC change vary with soil orders across different eco-climatic domains, controlled by all soil forming factors that affect carbon input and output; 2) within the same eco-climatic regime, the effects of disturbance on SOC change are controlled by physical and biogeochemical processes, represented by varying soil properties including clay, bulk density, pH, and CEC. To separate the effects of disturbance under different land-use scenarios on SOC change, space-for-time substitution was used in combination with the Continuous Change Detection and Classification algorithm and structural equation models. Results suggested that 1) under natural vegetation, Ultisols, Spodosols, and Inceptisols showed a large SOC accumulation especially in the eastern coast, while Inceptisols, Andisols, and Aridisols in the western US showed a large SOC loss; 2) compared with the same reference soils under natural vegetation, Mollisols and Alfisols showed a large SOC decrease due to human disturbance (e.g., farming and grazing); 3) Inceptisols (+6.2 g/kg) and Gelisols (+27.5 g/kg) in Alaska presented the largest SOC increase among all the soil orders within the subsoil (B horizon); 4) clay content and pH were the most dominant factors that affected SOC content across the NEON sites. This empirical analysis of the 30-years SOC change across eco-climatic regimes could be used for ecosystem modelers to benchmark the models across biomes and study the physical and biogeochemical controls on SOC change under different land management scenarios.</p>

Land-use Conflicts with Natural Vegetation in the United States

1979 ◽  
Vol 6 (3) ◽  
pp. 191-199 ◽  
Author(s):  
Jeffrey M. Klopatek ◽  
Richard J. Olson ◽  
Craig J. Emerson ◽  
Jan L. Joness
Keyword(s):  
United States ◽  
Land Use ◽  
Plant Communities ◽  
Vegetation Cover ◽  
The United States ◽  
Natural Vegetation ◽  
Computer Algorithm ◽  
Potential Natural Vegetation ◽  
Land Use Conflicts

There exists no current inventory of how much of the United States is occupied by natural vegetation, nor how much area is covered by particular plant communities. In this study, the potential existing vegetation-cover of the United States was determined by using a computer algorithm that was developed to subtract extant landuse data from the potential natural vegetation. This was done on a county-by-county basis for the 48 conterminous States.

Transportation Economic and Land Use System

1998 ◽  
Vol 1617 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Louis J. Pignataro ◽  
Joseph Wen ◽  
Robert Burchell ◽  
Michael L. Lahr ◽  
Ann Strauss-Wieder
Keyword(s):  
Land Use ◽  
Information System ◽  
Management Tool ◽  
Improvement Program ◽  
Transportation Projects ◽  
Accessible Information ◽  
Surface Transportation ◽  
Land Use System ◽  
Land Use Effects ◽  
Computer Based

The purpose of the Transportation Economic and Land Use System (TELUS) is to convert the transportation improvement program (TIP) into a management tool. Accordingly, the system provides detailed and easily accessible information on transportation projects in the region, as well as their interrelationships and impacts. By doing so, TELUS enables public-sector agencies to meet organizational, Intermodal Surface Transportation Efficiency Act, state, and other mandates more effectively. The objectives are accomplished by providing the computer-based capability to analyze, sort, combine, and track transportation projects in or under consideration for a TIP; assessing the interrelationships among significant transportation projects; estimating the regional economic and land use effects of transportation projects; and presenting project information in an easily understood format, including geographic information system formats.

scholarly journals Food security among dryland pastoralists and agropastoralists: The climate, land-use change, and population dynamics nexus

2021 ◽  
pp. 205301962110075
Author(s):  
Ilan Stavi ◽  
Joana Roque de Pinho ◽  
Anastasia K Paschalidou ◽  
Susana B Adamo ◽  
Kathleen Galvin ◽  
...  
Keyword(s):  
Land Use ◽  
Food Security ◽  
Management Practices ◽  
Relevant Literature ◽  
Global Changes ◽  
Food Utilization ◽  
Special Importance ◽  
Food Security Status ◽  
Global Action ◽  
Land Use And Management

During the last decades, pastoralist, and agropastoralist populations of the world’s drylands have become exceedingly vulnerable to regional and global changes. Specifically, exacerbated stressors imposed on these populations have adversely affected their food security status, causing humanitarian emergencies and catastrophes. Of these stressors, climate variability and change, land-use and management practices, and dynamics of human demography are of a special importance. These factors affect all four pillars of food security, namely, food availability, access to food, food utilization, and food stability. The objective of this study was to critically review relevant literature to assess the complex web of interrelations and feedbacks that affect these factors. The increasing pressures on the world’s drylands necessitate a comprehensive analysis to advise policy makers regarding the complexity and linkages among factors, and to improve global action. The acquired insights may be the basis for alleviating food insecurity of vulnerable dryland populations.

scholarly journals Exploring the variability of soil nutrient outflows as influenced by land use and management practices in contrasting agro-ecological environments

2021 ◽  
pp. 147450
Author(s):  
Temesgen Mulualem ◽  
Enyew Adgo ◽  
Derege Tsegaye Meshesha ◽  
Atsushi Tsunekawa ◽  
Nigussie Haregeweyn ◽  
...  
Keyword(s):  
Land Use ◽  
Management Practices ◽  
Soil Nutrient ◽  
Land Use And Management
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