Historical land use change and associated carbon emissions in Brazil from 1940 to 1995

Abstract. Several modeling studies reported elevated carbon emissions from historical land use change (LUC) by including bi-directional transitions at the sub-grid scale (termed gross land use change). This has implication on the estimation of so-called residual land CO2 sink over undisturbed lands. However, in most dynamic global vegetation models (DGVM), forests and/or other land use types are represented with a single sub-grid tile, without accounting for secondary lands that are often involved in shifting cultivation or wood harvest. As a result, land use change emissions (ELUC) are likely overestimated, because it is high-biomass mature forests instead of low-biomass secondary forests that are cleared. Here we investigated the effects of including sub-grid forest age dynamics in a DGVM on historical ELUC over 1501–2005. We run two simulations, one with no forest age (Sageless) and the other with sub-grid secondary forests of different age classes whose demography is driven by historical land use change (Sage). Estimated global ELUC for 1501–2005 are 179 Pg C in Sage compared to 199 Pg C in Sageless. The lower emissions in Sage arise mainly from shifting cultivation in the tropics, being of 27 Pg C in Sage against 46 Pg C in Sageless. Estimated cumulative ELUC from wood harvest in the Sage simulation (31 Pg C) are however slightly higher than Sageless (27 Pg C), because secondary forests simulated in Sage are insufficient to meet the prescribed harvest area, leading to the harvest of old forests. This result depends on pre-defined forest clearing priority rules given a simulated portfolio of differently aged forests in the model. Our results highlight that although gross land use change as a former missing emission component is included by a growing number of DGVMs, its contribution to overall ELUC tends to be overestimated, unless low-biomass secondary forests are properly represented.

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Smaller global and regional carbon emissions from gross land use change when considering sub-grid secondary land cohorts in a global dynamic vegetation model

Biogeosciences ◽

10.5194/bg-15-1185-2018 ◽

2018 ◽

Vol 15 (4) ◽

pp. 1185-1201 ◽

Cited By ~ 3

Author(s):

Chao Yue ◽

Philippe Ciais ◽

Wei Li

Keyword(s):

Land Use ◽

Land Use Change ◽

Carbon Emissions ◽

Shifting Cultivation ◽

Secondary Forest ◽

Secondary Forests ◽

Forest Age ◽

Rotation Length ◽

Historical Land Use ◽

Wood Harvest

Abstract. Several modelling studies reported elevated carbon emissions from historical land use change (ELUC) by including bidirectional transitions on the sub-grid scale (termed gross land use change), dominated by shifting cultivation and other land turnover processes. However, most dynamic global vegetation models (DGVMs) that have implemented gross land use change either do not account for sub-grid secondary lands, or often have only one single secondary land tile over a model grid cell and thus cannot account for various rotation lengths in shifting cultivation and associated secondary forest age dynamics. Therefore, it remains uncertain how realistic the past ELUC estimations are and how estimated ELUC will differ between the two modelling approaches with and without multiple sub-grid secondary land cohorts – in particular secondary forest cohorts. Here we investigated historical ELUC over 1501–2005 by including sub-grid forest age dynamics in a DGVM. We run two simulations, one with no secondary forests (Sageless) and the other with sub-grid secondary forests of six age classes whose demography is driven by historical land use change (Sage). Estimated global ELUC for 1501–2005 is 176 Pg C in Sage compared to 197 Pg C in Sageless. The lower ELUC values in Sage arise mainly from shifting cultivation in the tropics under an assumed constant rotation length of 15 years, being 27 Pg C in Sage in contrast to 46 Pg C in Sageless. Estimated cumulative ELUC values from wood harvest in the Sage simulation (31 Pg C) are however slightly higher than Sageless (27 Pg C) when the model is forced by reconstructed harvested areas because secondary forests targeted in Sage for harvest priority are insufficient to meet the prescribed harvest area, leading to wood harvest being dominated by old primary forests. An alternative approach to quantify wood harvest ELUC, i.e. always harvesting the close-to-mature forests in both Sageless and Sage, yields similar values of 33 Pg C by both simulations. The lower ELUC from shifting cultivation in Sage simulations depends on the predefined forest clearing priority rules in the model and the assumed rotation length. A set of sensitivity model runs over Africa reveal that a longer rotation length over the historical period likely results in higher emissions. Our results highlight that although gross land use change as a former missing emission component is included by a growing number of DGVMs, its contribution to overall ELUC remains uncertain and tends to be overestimated when models ignore sub-grid secondary forests.

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Carbon emissions from land-use change: an analysis of causal factors in Chiapas, Mexico

Mitigation and Adaptation Strategies for Global Change ◽

10.1007/s11027-006-9060-7 ◽

2006 ◽

Vol 12 (6) ◽

pp. 1213-1235 ◽

Cited By ~ 10

Author(s):

M. A. Castillo-Santiago ◽

A. Hellier ◽

R. Tipper ◽

B. H. J. de Jong

Keyword(s):

Land Use ◽

Land Use Change ◽

Carbon Emissions ◽

Causal Factors

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Regulating carbon emissions from indirect land use change (ILUC): U.S. and California case studies

Environmental Science & Policy ◽

10.1016/j.envsci.2017.07.016 ◽

2017 ◽

Vol 77 ◽

pp. 25-31 ◽

Cited By ~ 6

Author(s):

Hanna L. Breetz

Keyword(s):

Land Use ◽

Land Use Change ◽

Case Studies ◽

Carbon Emissions ◽

Indirect Land Use Change

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Estimating historical land use patterns in Amazonia for hydrological studies

Revista Ibero-Americana de Ciências Ambientais ◽

10.6008/spc2179-6858.2017.004.0016 ◽

2017 ◽

Vol 8 (4) ◽

pp. 189-197

Author(s):

Christiane Cavalcante Leite ◽

Marcos Heil Costa ◽

Ranieri Carlos Ferreira de Amorim

Keyword(s):

Land Use ◽

Water Resources ◽

Land Use Change ◽

Census Data ◽

Land Use Patterns ◽

Use Patterns ◽

The Past ◽

The World ◽

Historical Land Use ◽

Past Land Use

The evaluation of the impacts of land-use change on the water resources has been, many times, limited by the knowledge of past land use conditions. Most publications on this field present only a vague description of the past land use, which is usually insufficient for more comprehensive studies. This study presents the first reconstruction of the historical land use patterns in Amazonia, that includes both croplands and pasturelands, for the period 1940-1995. During this period, Amazonia experienced the fastest rates of land use change in the world, growing 4-fold from 193,269 km2 in 1940 to 724,899 km2 in 1995. This reconstruction is based on a merging of satellite imagery and census data, and provides a 5'x5' yearly dataset of land use in three different categories (cropland, natural pastureland and planted pastureland) for Amazonia. This dataset will be an important step towards understanding the impacts of changes in land use on the water resources in Amazonia.

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Carbon Emissions from Land-Use Change: Model Estimates Using Three Different Data Sets

Land Use and the Carbon Cycle ◽

10.1017/cbo9780511894824.013 ◽

2013 ◽

pp. 241-258 ◽

Cited By ~ 1

Author(s):

Atul K. Jain ◽

Prasanth Meiyappan ◽

Tosha Richardson

Keyword(s):

Land Use ◽

Land Use Change ◽

Carbon Emissions ◽

Data Sets ◽

Change Model ◽

Land Use Change Model

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The Net Carbon Emissions from Historic Land Use and Land Use Change

Journal of Forest Economics ◽

10.1561/112.00000505 ◽

2019 ◽

Vol 34 (3-4) ◽

pp. 263-283

Author(s):

Robert Mendelsohn ◽

Brent Sohngen

Keyword(s):

Land Use ◽

Land Use Change ◽

Carbon Emissions ◽

Historic Land Use

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Patterns of Historical and Future Urban Expansion in Nepal

Remote Sensing ◽

10.3390/rs12040628 ◽

2020 ◽

Vol 12 (4) ◽

pp. 628 ◽

Cited By ~ 3

Author(s):

Bhagawat Rimal ◽

Sean Sloan ◽

Hamidreza Keshtkar ◽

Roshan Sharma ◽

Sushila Rijal ◽

...

Keyword(s):

Land Use ◽

Land Use Change ◽

Land Use Planning ◽

Environmental Sustainability ◽

Urban Areas ◽

Urban Expansion ◽

Spatial Models ◽

Agricultural Conversion ◽

Historical Land Use ◽

Landsat Satellite

Globally, urbanization is increasing at an unprecedented rate at the cost of agricultural and forested lands in peri-urban areas fringing larger cities. Such land-cover change generally entails negative implications for societal and environmental sustainability, particularly in South Asia, where high demographic growth and poor land-use planning combine. Analyzing historical land-use change and predicting the future trends concerning urban expansion may support more effective land-use planning and sustainable outcomes. For Nepal’s Tarai region—a populous area experiencing land-use change due to urbanization and other factors—we draw on Landsat satellite imagery to analyze historical land-use change focusing on urban expansion during 1989–2016 and predict urban expansion by 2026 and 2036 using artificial neural network (ANN) and Markov chain (MC) spatial models based on historical trends. Urban cover quadrupled since 1989, expanding by 256 km2 (460%), largely as small scattered settlements. This expansion was almost entirely at the expense of agricultural conversion (249 km2). After 2016, urban expansion is predicted to increase linearly by a further 199 km2 by 2026 and by another 165 km2 by 2036, almost all at the expense of agricultural cover. Such unplanned loss of prime agricultural lands in Nepal’s fertile Tarai region is of serious concern for food-insecure countries like Nepal.

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