Remote sensing-based assessment of mangrove ecosystems in the Gulf Cooperation Council countries: a systematic review

Mangrove forests in the Gulf Cooperation Council (GCC) countries are facing multiple threats from natural and anthropogenic-driven land use change stressors, contributing to altered ecosystem conditions. Remote sensing tools can be used to monitor mangroves, measure mangrove forest-and-tree-level attributes and vegetation indices at different spatial and temporal scales that allow a detailed and comprehensive understanding of these important ecosystems. Using a systematic literature approach, we reviewed 58 remote sensing-based mangrove assessment articles published from 2010 through 2022. The main objectives of the study were to examine the extent of mangrove distribution and cover, and the remotely sensed data sources used to assess mangrove forest/tree attributes. The key importance of and threats to mangroves that were specific to the region were also examined. Mangrove distribution and cover were mainly estimated from satellite images (75.2%), using NDVI (Normalized Difference Vegetation Index) derived from Landsat (73.3%), IKONOS (15%), Sentinel (11.7%), WorldView (10%), QuickBird (8.3%), SPOT-5 (6.7%), MODIS (5%) and others (5%) such as PlanetScope. Remotely sensed data from aerial photographs/images (6.7%), LiDAR (Light Detection and Ranging) (5%) and UAV (Unmanned Aerial Vehicles)/Drones (3.3%) were the least used. Mangrove cover decreased in Saudi Arabia, Oman, Bahrain, and Kuwait between 1996 and 2020. However, mangrove cover increased appreciably in Qatar and remained relatively stable for the United Arab Emirates (UAE) over the same period, which was attributed to government conservation initiatives toward expanding mangrove afforestation and restoration through direct seeding and seedling planting. The reported country-level mangrove distribution and cover change results varied between studies due to the lack of a standardized methodology, differences in satellite imagery resolution and classification approaches used. There is a need for UAV-LiDAR ground truthing to validate country-and-local-level satellite data. Urban development-driven coastal land reclamation and pollution, climate change-driven temperature and sea level rise, drought and hypersalinity from extreme evaporation are serious threats to mangrove ecosystems. Thus, we encourage the prioritization of mangrove conservation and restoration schemes to support the achievement of related UN Sustainable Development Goals (13 climate action, 14 life below water, and 15 life on land) in the GCC countries

Forest Governance Effectiveness of Community- and Government-managed Forests in Cameroon

Effective implementation of forest governance principles such as transparency, participation, accountability, coordination, capacity, user rights protection and security driven by positive government interventions are instrumental for sustainable forest management. The study used satellite-derived data to explore forest loss in community forest (CF) and government-managed forest in Cameroon from 2001 to 2014. The study also examined the extent to which community forest rights are legally recognised and protected and how government interventions undermine or promote CF management effectiveness in Cameroon. The rationale was to understand the forest outcome of different forest management approaches with varied user rights and management objectives. This is considering that community forest managers have been seen as better managers of forests than government agencies, if their full rights are well recognised and protected. We used semi-structured open-ended questionnaires, followed by focus group interviews with CF management institutions and document review for data collection. Forest loss showed significant increasing trends and was higher in CF than in other forest management types from 2001 to 2014. Stakeholder perceptions of CF rights and government intervention or actions varied between CF management institutions. Community forest rights such as rights to full ownership and control, full management, unlimited duration, alienation, and due process and compensation are not legally recognised and/or protected in community forestry in Cameroon, producing negative forest outcomes. Negative government interventions such as imposing excessive bureaucratic obstacles and initial financial investment in the processing of application files for CF applications and commercial user rights of timber harvesting, colluding with local elites, individuals and corrupt municipal and administrative authorities, and retaining full administrative ownership and control of CF land and resources, also produces negative forest outcomes. The non- recognition and protection of higher level CF rights and excessive negative government interventions in CF management contributes to undermining community’s willingness and readiness to prevent deforestation activities and voluntary engagement in conservation activities involving tree planting and management for long term community benefits. Therefore, recognising, strengthening and protecting all the CF rights proposed by the Rights and Resources Initiative and avoiding negative government interventions in CF management are helpful strategies in achieving the expected conservation and local development objectives of CF in Cameroon and in the Congo basin region

Responses of zooplankton to cane sugar additions to a small humic lake, Alinen Mustajärvi

The response to projected increase in dissolved organic carbon (DOC) loading to boreal lakes is being studied in lake Alinen Mustajärvi, a small humic lake in southern Finland, where labile DOC concentration has been artificially increased during 2008 and 2009 by monthly additions of cane sugar. As part of this wider project, in this thesis the responses of the zooplankton community to cane sugar addition were studied. Zooplankton samples were collected monthly in the ice-free periods of 2007, 2008 and 2009 and the mean densities and mean carbon biomasses of rotifers and crustacean zooplankton (cladocerans and copepods) were calculated. Stable isotope analyses (δ13C and δ15N) were made for the crustacean zooplankton samples. Zooplankton respond to additions of DOC by an appreciable increase in the mean density of rotifers and carbon biomass of copepods, while both the mean density and carbon biomass of cladocerans showed a decrease between years. Values for δ13C increased progressively across the years, especially for cladocerans, but less so for copepods. This suggests strongly that appreciable DOC from sugar additions was being transferred to zooplankton by heterotrophic bacteria and zooplankton dependence on heterotrophic bacteria appeared to increase with the increased loading of DOC in lake Alinen Mustajärvi

Table_1_Remote sensing-based assessment of mangrove ecosystems in the Gulf Cooperation Council countries: a systematic review.pdf

Mangrove forests in the Gulf Cooperation Council (GCC) countries are facing multiple threats from natural and anthropogenic-driven land use change stressors, contributing to altered ecosystem conditions. Remote sensing tools can be used to monitor mangroves, measure mangrove forest-and-tree-level attributes and vegetation indices at different spatial and temporal scales that allow a detailed and comprehensive understanding of these important ecosystems. Using a systematic literature approach, we reviewed 58 remote sensing-based mangrove assessment articles published from 2010 through 2022. The main objectives of the study were to examine the extent of mangrove distribution and cover, and the remotely sensed data sources used to assess mangrove forest/tree attributes. The key importance of and threats to mangroves that were specific to the region were also examined. Mangrove distribution and cover were mainly estimated from satellite images (75.2%), using NDVI (Normalized Difference Vegetation Index) derived from Landsat (73.3%), IKONOS (15%), Sentinel (11.7%), WorldView (10%), QuickBird (8.3%), SPOT-5 (6.7%), MODIS (5%) and others (5%) such as PlanetScope. Remotely sensed data from aerial photographs/images (6.7%), LiDAR (Light Detection and Ranging) (5%) and UAV (Unmanned Aerial Vehicles)/Drones (3.3%) were the least used. Mangrove cover decreased in Saudi Arabia, Oman, Bahrain, and Kuwait between 1996 and 2020. However, mangrove cover increased appreciably in Qatar and remained relatively stable for the United Arab Emirates (UAE) over the same period, which was attributed to government conservation initiatives toward expanding mangrove afforestation and restoration through direct seeding and seedling planting. The reported country-level mangrove distribution and cover change results varied between studies due to the lack of a standardized methodology, differences in satellite imagery resolution and classification approaches used. There is a need for UAV-LiDAR ground truthing to validate country-and-local-level satellite data. Urban development-driven coastal land reclamation and pollution, climate change-driven temperature and sea level rise, drought and hypersalinity from extreme evaporation are serious threats to mangrove ecosystems. Thus, we encourage the prioritization of mangrove conservation and restoration schemes to support the achievement of related UN Sustainable Development Goals (13 climate action, 14 life below water, and 15 life on land) in the GCC countries.</p