Forest condition in the Congo Basin for the assessment of ecosystem conservation status

Abstract

14Measuring forest degradation is important for understanding and designing measures to protect 15 biodiversity and the capacity of forests to deliver ecosystem services. Conservation planning, 16 particularly the prioritization of management interventions for forests, is often lacking spatial data on 17 ecological condition, and it is often overlooked within decision-making processes. Existing methods 18for assessing forest degradation via proxies or binary measures (i.e. intact or not) cannot adequately 19consider the important variations of ecological condition. Direct methods to measure degradation 20 (e.g. through remote sensing) require extensive training data, calibration and validation, and may be 21 too sensitive to small-scale or short-term changes which may not be related to degradation. We 22 developed a metric termed Forest Condition (FC) which aims to measure the degree of forest 23 degradation, incorporating temporal history of forest change over a large spatial extent. We 24 parameterized this metric based on estimated changes in above ground biomass in the context of 25 forest fragmentation over time to estimate a continuous measure of forest degradation for Congo 26Basin countries. We estimate that just less than 70% of Congo Basin forests remain fully intact. FC 27 was validated by direct remote sensing measurements from Landsat imagery for DRC. Results 28 showed that FC was significantly positively correlated with forest canopy cover, gap area per hectare, 29and magnitude of temporal change in Normalized Burn Ratio. We tested the ability of FC to 30 distinguish primary and secondary degradation and deforestation and found significant differences in 31 gap area and spectral anomalies to validate our theoretical model. We used the IUCN Red List of 32Ecosystems criteria to demonstrate the value of applying forest degradation to assess the risk of 33 ecosystem collapse. Based on this assessment, we found that without including FC in the assessment 34 of biotic disruption, 12 ecosystems could not have a threat status assigned, and a further 9 35 ecosystems would have a lower threat status. Our overall assessment of ecosystems found 36 approximately half of forest of Congo Basin ecosystem types which cover over 20% of all forest area 37 are threatened including 4 ecosystems (<1% of total area) which are critically engendered. FC is a 38 transferrable and scalable assessment to support forest monitoring, planning, and management. 39

Change in Terrestrial Human Footprint Drives Continued Loss of Intact Ecosystems

“…58,59 In addition, remote African forests, such as the Congo Basin, are increasingly impacted by roads, population growth, and subsistence agriculture. 60,61 Other regions experiencing extreme levels of intact ecosystem loss are the rainforests of Indonesia (which covers 1.3% of Earth but contains 10% of the world's plants, 12% of mammals, 16% of reptile-amphibians, and 17% of birds) 62 and Papua New Guinea (which covers less than 1% of Earth but contains 5% of its biodiversity). 63 This extreme habitat loss is likely due to the spike in habitat conversion to grow cash crops, such as oil palm, 64,65 driven by international demand.…”

Patterns and drivers of disturbance in tropical forest reserves of southern Ghana

“…We used the Landscape Fragmentation Tool to classify forest pixels into six groups with varying degrees of fragmentation: large core (most intact), medium core, small core, inner edge, edge, and patch (most fragmented) (Vogt et al 2007a, 2007b, Shapiro et al 2016. We used an edge distance of 300 m which is considered appropriate for measuring edge effects into unfragmented tropical forests (Shapiro et al 2016(Shapiro et al , 2021. Percent closed forest was generated from the 30 m canopy rasters using a 210 m radius circular moving window.…”

The importance of choosing appropriate methods for assessing wild food plant knowledge and use: A case study among the Baka in Cameroon

“…Wild edible plants also provide a safety net in times of agricultural shortage and are thus essential for food security [ 9 ]. However, forest-dwelling societies in the Congo Basin are challenged by a decrease in access to and availability of wild food resources due to the increasing exploitation of the forests for commercial hardwood, precious minerals, and space for oil palm and rubber plantations [ 10 , 11 ]. As a result of large-scale agricultural encroachment, logging, mining and hunting activities, the ecosystems of this region are under severe pressure [ 10 , 12 ].…”

“…As a result of large-scale agricultural encroachment, logging, mining and hunting activities, the ecosystems of this region are under severe pressure [ 10 , 12 ]. A recent survey estimated that just 70% of the standing forests of the Congo Basin remain fully intact [ 11 ]. Pressures on local resources have led to a decrease in local people’s access to the important wild plants and bushmeat, which contributes substantially to their diet and medicine [ 13 , 14 ].…”