Anthropogenic Drivers of Mangrove Loss and Associated Carbon Emissions in South Sumatra, Indonesia

<p>Mangrove and other coastal wetlands such as saltmarsh and seagrass are termed ‘blue carbon’ ecosystems due to their substantial capacity for carbon storage and sequestration over a long-term time scale. Policymakers and stakeholders are currently promoting mangroves into national carbon management as part of nature-based climate change mitigation and adaptation strategy. Unfortunately, global mangroves area with particularly in the tropics is decreasing at a rapid rate due to land-use and land-cover change (LULCC). Yet, there has been limited study of carbon emissions impacted by multiple mangrove conversions at the landscape scale. Here we assessed spatio-temporal patterns of soil CO<sub>2</sub> and CH<sub>4</sub> effluxes across six land uses, namely mangroves converted to 15 yrs oil palm, 20 yrs coconut, and 20 yrs aquaculture (pond wall and water surface), as well as newly logged mangrove, 10 yrs planted mangrove, and undisturbed mangrove forests reference in North Sumatra, Indonesia. Direct measurement of soil CO<sub>2</sub> and CH<sub>4</sub> effluxes were performed by using an ultra-portable LGR gas analyser during low tide condition between 08.00 and 16.00, with triplicated PVC 10-inch diameter and 25 cm height opaque static chambers (closed system) were installed at each land use in September-October 2021 -- representing wet season in the study site. The soil CO<sub>2</sub> and CH<sub>4</sub> effluxes were collected three times for each chamber and 3 days of measurement during this field campaign with a total of 193 measurements were performed. We observed that the top three highest soil CO<sub>2</sub> and CH<sub>4</sub> effluxes were among aquaculture pond wall soils (591±104 mgCO<sub>2</sub> m<sup>2</sup> h<sup>-1</sup> and 0.40±0.17 mgCH<sub>4</sub> m<sup>2</sup> h<sup>-1</sup>), logged mangroves (480±104 mgCO<sub>2</sub> m<sup>2</sup> h<sup>-1</sup> and 3.21±1.34 mgCH<sub>4</sub> m<sup>2</sup> h<sup>-1</sup>), and natural mangroves (274±71 mgCO<sub>2</sub> m<sup>2</sup> h<sup>-1</sup> and 0.58±0.28 mgCH<sub>4</sub> m<sup>2</sup> h<sup>-1</sup>). By contrast, relatively low effluxes (< 200 mgCO<sub>2</sub> m<sup>2</sup> h<sup>-1</sup> and < 0.1 mgCH<sub>4</sub> m<sup>2</sup> h<sup>-1</sup>) were observed across other land-use types. Our preliminary results suggest that the variation of soil CO<sub>2</sub> and CH<sub>4</sub> in our study sites may be controlled by the duration of the disturbances, particularly we observed the highest CO<sub>2</sub> and CH<sub>4</sub> effluxes at newly (occurred at the same year with our measurement) constructed pond wall and logged mangrove locations. On the other hand, low CO<sub>2</sub> and CH<sub>4</sub> effluxes were observed at both oil palm and coconut plantations. These new land uses were constructed more than 10 years ago with the application of drainage and tidal blocking. Our current limited data constraint further essential factors that commonly control CO<sub>2</sub> and CH<sub>4</sub> in the coastal wetlands, such as tidal elevation, bioturbation, seasonal variation, and soil properties. Overall, our dataset will be essential to guide policymakers in related to the improvement of land-based low carbon development and climate change mitigation strategies for Indonesia to meet the targeted 29% of unconditional carbon emissions reduction by 2030 as outlined in the Nationally Determined Contributions (NDCs) as part of the Paris Agreement.</p>

Abstract. Eddy S, Milantara N, Basyuni M. 2021. Carbon emissions as impact of mangrove degradation: A case study on the Air Telang Protected Forest, South Sumatra, Indonesia (2000-2020). Biodiversitas 22: 2142-2149. Massive degradation in ATPF occurs due to anthropogenic activities that have converted this area into a coconut plantation, fishpond, settlement, and agriculture. The purpose of this study was to describe changes in land cover and the amount of CO2 emission in ATPF and its causes during the 2000-2020 period using remote sensing data. Data from remote sensing were used to obtain area, classification and land cover change in each period; meanwhile, carbon stock, emissions, and CO2 sequestration were obtained from the analysis using LUMENS software. The results showed that the emissions resulting from land conversion in ATPF during the 2000-2020 period were much greater than sequestration. Net emissions of 1,928,076.56 tons of CO2-eq with an annual emission rate of 96,403.83 tons of CO2-eq/year. The largest source of emissions came from the conversion of primary forest, coconut plantation and secondary forest to open areas; while the source of sequestration comes from the formation of primary and secondary forests. There need to be restoration and conservation efforts in this area by the government and the community to restore the function of ATPF as a coastal protection forest. This research is the first study to examine land cover changes in mangrove forests using data analysis methods with LUMENS.

Eddy S, Iskandar I, Ridho MR, Mulyana A. 2017. Land cover changes in the Air Telang Protected Forest, South Sumatra, Indonesia (1989-2013). Biodiversitas 18: 1538-1545. The Air Telang Protected Forest (ATPF) is a mangrove forest in the Banyuasin District, South Sumatra, Indonesia. It has an area of about 12,660.87 ha. In fact, that the ATPF area has been converted into aquacultures, plantations, agricultural lands, settlements and ports during recent decades. The objective of this study is to identify the land cover changes in the ATPF from 1989 through 2013 using satellite remote sensing data. Three Landsat satellite imageries for 1989, 2001 and 2013 have been used to build maps and to predict the land cover changes in the study area. A ground-truthing verification was done to increase the accuracy of image classification in each region. The results showed that the anthropogenic forcing had caused significant degradation of primary mangrove forest in the ATPF from 1989 to 2013. This forcing was categorized as mangrove conversion into coconut plantations, oil palm plantations, aquacultures, farms, ports, and settlements. Of these six conversions, the coconut plantations, oil palm plantations and aquacultures have potential tendencies to increase construction that could threaten the existence of mangrove forest in ATPF. It was found that during 2013, the coconut plantations, oil palm plantations, and aquacultures accounted for about 18.0% (2,278.62 ha), 4.7% (591.87 ha) and 3.1% (386.18 ha) of mangrove forest changes, respectively.

Forest and wood land ecosystems in Tanzania occupy more than 45% of the land area, more than two thirds of which made up of the Miombo woodland. The main form of land use in the Miombo region has long been shifting and small-scale sedentary cultivation. The lack of infrastructure and prevalence of deadly diseases such as malaria and trypanosiomiasis have long limited extensive clearance for cultivation, livestock farming and settlements. However, due to positives changes in the socio-economical, political and technological setup in miombo region, the types and intensity of land use are now changing. This paper discusses preliminary results from a study conducted with the aim of contributing to the understanding of dynamics of land cover and use changes in miombo woodlands of eastern Tanzania. The study area comprises four villages around the “Kitulangalo Forest Reserve”, 140 km west of Dar es Salaam on either side of the Morogoro-Dar es Salaam highway. Landsat MSS satellite images of July 1975, Landsat TM satellite images of July 2000 were used to assess land cover changes between 1975 and 2000. Participatory Rural Appraisal (PRA), questionnaire survey and checklists for key informants were the major methods used for collecting socio-economic data. The land cover/use class of woodland with scattered cultivation has recorded the highest percentage of change between July 1975 and July 2000. While all other classes have registered positive changes, only the closed woodland class has had negative change meaning that this class has been decreasing in favour of other land cover/use classes. Recent land cover and use changes are drastic in the study area. These changes have been triggered largely by varied factors including mainly increased population density and subsequent economic activities. Economic activities including charcoal business, shifting cultivation, opening up of improved highway and pastoralism in the study area have greatly contributed to deforestation and woodland degradation. In light of these findings, there is need for: (1) Adequate land use planning and survey of village lands so as to avoid exacerbation of land use conflict and environmental degradation in the study area. (2) Agrarian reforms to eliminate open access regimes to natural resources. (3) Enforcement of fiscal policies related to the extraction of natural resource products such as timber and charcoal so as to reduce pressure on woodlands. Keywords: land use – cover change – Kitulangalo – miombo woodlands

Land use and land cover changes (LULCC) as a part of ecosystems has a significant impact on carbon budget. According to IPCC, approximately 23% of carbon was emitted from the human activities in agriculture, forestry and other land use (AFOLU) from 2007 to 2016. However, land cover includes crucial sector for carbon stock, as well. The land cover consists of five categories which are used area, agricultural land, forest, grass, wet land, and barren. Among these categories, forest counts because of its capacity of carbon sequestration. It is essential to manage the land use and land cover changes effectively since it has lots of influences on carbon cycles. Also, the sustainable management of land use and land cover changes could contribute to reducing the carbon emissions such as preventing deforestation and revegetation. Therefore, this study aims at analyzing the frequent land use change region using hot spot analysis in South Korea and North Korea and estimating the carbon emission and removals from land cover changes. First of all, we tracked the land cover changes at 10 years interval from 1980s to 2010s and identified the general trends. The changed area and ratio of each land cover were varied in both countries, but they had similar characteristics which is land cover changes from forest to cropland and from cropland to forest. It occurred for last four decades. To define the which region has been changed, the hot spot analysis was utilized. The change from forest to cropland appeared in southwest region of North Korea, major agriculture land. On the other hand, the transition from agriculture land to forest seemed to be minor, but the distinguished figure was created during the 2000s to 2010s change. The carbon emission was estimated at the hot spot area and these repeated changes led to additional carbon emission. This study would contribute to preventing the land cover changes frequent by defining the region to be managed.

For many developing countries, the land use sector, particularly agriculture and forestry, represents a large proportion of their greenhouse gas (GHG) emissions, making this sector a priority for GHG mitigation activities. Previous global surveys (e.g., IPCC 2000) as well as the most recent IPCC assessment report clearly indicate that the greatest technical potential for carbon sequestration and reductions of non-CO2 GHG emissions from the land use sector is in developing countries. Estimates that consider economic feasibility suggest that agriculture and forestry together provide among the greatest opportunities for short-term and low-cost mitigation measures across all sectors of the global economy1 (IPCC 2007). In addition, it is widely recognized that the ecosystem changes entailed by most mitigation practices, i.e., building soil organic matter, reducing losses and tightening nutrient cycles, more efficient production systems and preserving native vegetation, are well aligned with goals of increasing food security and rural development as well as buffering land use systems against climate change (Lal 2004). Hence, there is growing interest in jump-starting the capacity for broad-based engagement in agriculturally-based GHG mitigation projects in developing countries.

Solely economic mitigation strategy suggests upward revision of nationally determined contributions

Carbon sources and sinks as a result of land use and land cover changes (LUCC) are significant for global climate change. This paper aims to identify and analyze the temporal and spatial changes of land use-based carbon emission in the Hubei Province in China. We use a carbon emission coefficient to calculate carbon emissions in different land use patterns in Hubei Province from 1998 to 2009. The results indicate that regional land use is facing tremendous pressure from rapid carbon emission growth. Source:sink ratios and average carbon emission intensity values of urban land are increasing, while slow-growing carbon sinks fail to offset the rapidly expanding carbon sources. Overall, urban land carbon emissions have a strong correlation with the total carbon emissions, and will continue to increase in the future mainly due to the surge of industrialization and urbanization. Furthermore, carbon emission in regions with more developed industrial structures is much higher than in regions with less advanced industrial structures. Lastly, carbon emission per unit of GDP has declined since 2004, indicating that a series of reform measures i.e., economic growth mode transformation and land-use structure optimization, has initiated the process of carbon emission reduction.

The ongoing land use and land cover changes (LUCC) in Indonesia significantly contribute to climate warming and land degradation. At the same time, competing policy frameworks and land contestation are emerging, particularly regarding degraded land utilization for restoration and commodity production (e.g., timber, bioenergy). However, no study has assessed, at the national scale, the spatial availability of degraded land suitable for timber plantations and the associated carbon implications. Here, we combine a Geographical Information System (GIS)-based land suitability analysis with a dynamic material flow and life cycle assessment (MFA–LCA) framework to evaluate the climate mitigation potential of restoring degraded lands for wood materials and energy in Indonesia. The GIS analysis identifies 0.44–3.60 Mha of degraded land suitable for Acacia, Teak, and Rubber plantations, depending on degraded land definitions and biophysical constraints. The dynamic MFA–LCA model quantifies temporal carbon emissions and sequestration from biospheric and technospheric carbon flows over a 200-year time horizon. Our results show reforesting degraded land exhibits the highest climate benefit, achieving up to −456 Mt CO 2 -eq over 200 years. In comparison, wood plantations yield less mitigation effects, with cumulative emissions ranging from −324 to 1130 Mt CO 2 -eq depending on species and scenarios. Teak offers the greatest long-term carbon sequestration potential (−47 to −324 Mt CO 2 -eq), while fast-growing Acacia supports short-term targets, potentially reducing Indonesia's 2030 Nationally Determined Contributions (NDC) emissions by 5.7%. These findings highlight the need for policies that balance immediate emission reductions with long-term carbon sequestration through spatially targeted degraded land restoration. • Spatially explicit degraded land scenarios to grow wood plantations in Indonesia. • Teak generates lower carbon emissions than Acacia and Rubber in the long-term. • Reforesting restored degraded land exhibits the highest climate benefit. • From a climate perspective, leaving the degraded land idle shall be avoided.

Research on future land cover changes and carbon emissions is essential for effective land resource management and developing feasible carbon mitigation strategies. This study focused on the Yellow River Basin and employed the Future Land Use Simulation (FLUS) and Autoregressive Integrated Moving Average (ARIMA) models to project future land cover and carbon emissions. Additionally, bivariate spatial autocorrelation was utilized to analyze the relationship between them. Key findings are as follows: 1) Historically, the Yellow River Basin has experienced an expansion in construction land, forests, grasslands, and water, while cropland and unused land have diminished. Notably, construction land displayed the most significant changes, whereas grasslands showed minimal modification. Looking ahead, both the ecological protection and inertial development scenarios exhibit consistent trends with historical patterns across the land type categories. In contrast, the economic priority development scenario forecasts an increase in construction land, cropland, and grasslands, indicating a distinct shift compared to the other scenarios. However, the ecological protection scenario proves to be more sustainable. 2) In the absence of intervention, the simulated carbon emissions from construction land throughout the basin display a linear increase across various scenarios, with provincial-level variations showing an increase from southwest to northeast. However, Henan and Sichuan are expected to experience slower reductions in carbon emissions, compared to other projections. There is a notable positive correlation between carbon emissions and the comprehensive index, indicating that regions with high emissions typically experience substantial land and economic development. 3) Energy consumption projections for 2030 and 2060 indicate that to align with China’s carbon goals, it is essential to reduce energy consumption and adjust the fossil to non-fossil fuel ratio to reduce carbon emissions. Substituting coal with clean energy and enhancing energy efficiency will be more effective for achieving low-carbon emission targets. In summary, this study provides significant guidance for China’s ecological conservation, low-carbon emission strategies, and global carbon emission control efforts.

The study aimed to assess the changes that have occurred in land use and land cover within the Maasai Mara landscape using remote sensed data from 1997 to 2017; examine the elephant distribution in relation to land use and land cover changes within the Mara landscape and to determine changes in elephant home ranges in relation to Land use and cover changes in the Mara landscape. In examining the land use and land cover changes on the elephant ranges and distribution, an integrated methodological approach was employed in which the changes that have taken place within the study area over a period of 20 years was determined by analysis involving a 10-year changes in land use and land cover using three epochs from 1997, 2007 and 2017 to generate six land use classes. The Maasai Mara Landscape (MML) supports one of the richest wildlife populations remaining on earth but over the last century, has experienced transformation notably through conversion of former rangelands into croplands. Elephants have both temporal and spatial requirements, which if not provided, render them vulnerable to the land-use practices. The study assessed land use and vegetation cover changes that have occurred and their effects on the elephant movements and distribution within the MML using an integrated methodological approach. The analysis revealed changes in land use and land cover classes over a period of 20 years for the three epochs, from 1997, 2007 and 2017. Elephant’s distribution has been restricted to areas of high vegetation densities within specific habitats hence accelerating the rate of habitat destruction and degradation due to their high densities. These changes have drastically reduced forage for elephants necessitating them to travel longer distances out of their home range in search for food. Human beings have caused land use and cover changes which have detrimental impacts on the ecosystem and ecosystem services. The Maasai Mara landscape supports one of the richest wildlife populations remaining on earth but over the last century, it has experienced land transformation notably through conversion of former rangelands used mainly for tourism and production of grains such as wheat. Land outside the national parks and the reserve is important to the future of elephant existence in Kenya. Little is known about how human occupation on these landscapes negatively affects elephants (Loxodonta africana) habitats, movement and ranges. This has been confirmed by the current continuous demarcation/fencing of land in most areas in Narok County. Elephants like other landscape species, have both temporal and spatial requirements, which if not provided, will render them vulnerable to the land use practices of people. The study aimed to assess the changes that have occurred in land use and land cover within the Maasai Mara landscape using remote sensed data from 1997 to 2017; examine the elephant distribution in relation to land use and land cover changes within the Mara landscape and to determine changes in elephant home ranges in relation to Land use and cover changes in the Mara landscape. The paper describes the different changes that have taken place within the MML and how these changes have affected elephant populations, their trend and distribution within the MML. In examining the land use and land cover changes on the elephant ranges and distribution, an integrated methodological approach was employed in which the changes that have taken place within the study area over a period of 20 years was determined by analysis involving a 10-year changes in land use and land cover using three epochs from 1997, 2007 and 2017 to generate six land use classes. The study found out that there were significant changes of various classes across the years. Forest, water and open shrubs coverages decreased from 1997 to 2017. Classification noted a serious problem within the study area of continuous increase of bare ground coverage across the study years. Elephant populations have been increasing within the area .at an annual rate of 2.69%. The animals are distributed all over the landscape. Distribution of elephants has been restricted to high densities within a specific habitat hence accelerating rate of habitat destruction and degradation due to their high densities within a specific habitat. These changes have reduced drastically foliage for elephants thus necessitating them to travel longer distances in search and as a result increases elephant home ranges.

To demonstrate potential future consequences of land cover and land use changes beyond those for physical climate and the carbon cycle, we present an analysis of large‐scale impacts of land cover and land use changes on atmospheric chemistry using the chemistry‐climate model EMAC (ECHAM5/MESSy Atmospheric Chemistry) constrained with present‐day and 2050 land cover, land use, and anthropogenic emissions scenarios. Future land use and land cover changes are expected to result in an increase in global annual soil NO emissions by ∼1.2 TgN yr−1 (9%), whereas isoprene emissions decrease by ∼50 TgC yr−1 (−12%). The analysis shows increases in simulated boundary layer ozone mixing ratios up to ∼9 ppbv and more than a doubling in hydroxyl radical concentrations over deforested areas in Africa. Small changes in global atmosphere‐biosphere fluxes of NOx and ozone point to compensating effects. Decreases in soil NO emissions in deforested regions are counteracted by a larger canopy release of NOx caused by reduced foliage uptake. Despite this decrease in foliage uptake, the ozone deposition flux does not decrease since surface layer mixing ratios increase because of a reduced oxidation of isoprene by ozone. Our study indicates that the simulated impact of land cover and land use changes on atmospheric chemistry depends on a consistent representation of emissions, deposition, and canopy interactions and their dependence on meteorological, hydrological, and biological drivers to account for these compensating effects. It results in negligible changes in the atmospheric oxidizing capacity and, consequently, in the lifetime of methane. Conversely, we expect a pronounced increase in oxidizing capacity as a consequence of anthropogenic emission increases.

Abstract. The Paris Agreement commits 197 countries to achieve climate stabilisation at a global average surface temperature less than 2 ∘C above pre-industrial times using nationally determined contributions (NDCs) to demonstrate progress. Numerous industrialised economies have targets to achieve territorial climate neutrality by 2050, primarily in the form of “net zero” greenhouse gas (GHG) emissions. However, particular uncertainty remains over the role of countries' agriculture, forestry, and other land use (AFOLU) sectors for reasons including the potential trade-offs between GHG mitigation and food security, a non-zero emission target for methane as a short-lived GHG, and the requirement for AFOLU to act as a net sink to offset residual emissions from other sectors. These issues are represented at a coarse level in integrated assessment models (IAMs) that indicate the role of AFOLU in global pathways towards climate stabilisation. However, there is an urgent need to determine appropriate AFOLU management strategies at a national level within NDCs. Here, we present a new model designed to evaluate detailed AFOLU scenarios at national scale using the example of Ireland, where approximately 40 % of national GHG emissions originate from AFOLU. GOBLIN (General Overview for a Backcasting approach of Livestock INtensification) is designed to run randomised scenarios of agricultural activities and land use combinations within biophysical constraints (e.g. available land area, livestock productivities, fertiliser-driven grass yields, and forest growth rates). Using AFOLU emission factors from national GHG inventory reporting, GOBLIN calculates annual GHG emissions out to the selected target year for each scenario (2050 in this case). The long-term dynamics of forestry are represented up to 2120 so that scenarios can also be evaluated against the Paris Agreement commitment to achieve a balance between emissions and removals over the second half of the 21st century. Filtering randomised scenarios according to compliance with specific biophysical definitions (GHG time series) of climate neutrality will provide scientific boundaries for appropriate long-term actions within NDCs. We outline the rationale and methodology behind the development of GOBLIN, with an emphasis on biophysical linkages across food production, GHG emissions, and carbon sinks at a national level. We then demonstrate how GOBLIN can be applied to evaluate different scenarios in relation to a few possible simple definitions of “climate neutrality”, discussing opportunities and limitations.

Abstract. Parties to the Paris Agreement (PA, 2015) outline their planned contributions towards achieving the PA temperature goal to “hold […] the increase in the global average temperature to well below 2 ∘C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 ∘C” (Article 2.1.a, PA) in their nationally determined contributions (NDCs). Most NDCs include targets to mitigate national greenhouse gas (GHG) emissions, which need quantifications to assess i.a. whether the current NDCs collectively put us on track to reach the PA temperature goals or the gap in ambition to do so. We implemented the new open-source tool “NDCmitiQ” to quantify GHG mitigation targets defined in the NDCs for all countries with quantifiable targets on a disaggregated level and to create corresponding national and global emissions pathways. In light of the 5-year update cycle of NDCs and the global stocktake, the quantification of NDCs is an ongoing task for which NDCmitiQ can be used, as calculations can easily be updated upon submission of new NDCs. In this paper, we describe the methodologies behind NDCmitiQ and quantification challenges we encountered by addressing a wide range of aspects, including target types and the input data from within NDCs; external time series of national emissions, population, and GDP; uniform approach vs. country specifics; share of national emissions covered by NDCs; how to deal with the Land Use, Land-Use Change and Forestry (LULUCF) component and the conditionality of pledges; and establishing pathways from single-year targets. For use in NDCmitiQ, we furthermore construct an emissions data set from the baseline emissions provided in the NDCs. Example use cases show how the tool can help to analyse targets on a national, regional, or global scale and to quantify uncertainties caused by a lack of clarity in the NDCs. Results confirm that the conditionality of targets and assumptions about economic growth dominate uncertainty in mitigated emissions on a global scale, which are estimated as 48.9–56.1 Gt CO2 eq. AR4 for 2030 (10th/90th percentiles, median: 51.8 Gt CO2 eq. AR4; excluding LULUCF and bunker fuels; submissions until 17 April 2020 and excluding the USA). We estimate that 77 % of global 2017 emissions were emitted from sectors and gases covered by these NDCs. Addressing all updated NDCs submitted by 31 December 2020 results in an estimated 45.6–54.1 Gt CO2 eq. AR4 (median: 49.6 Gt CO2 eq. AR4, now including the USA again) and increased coverage.

How a socio-ecological metabolism approach can help to advance our understanding of changes in land-use intensity