4. Discussion
Protection, conservation and sustainable management of forest resources are often challenging (Siry et al., 2003), especially for a country like Bangladesh. The forest resources of the country are already in a critical state because of a number of reasons, including high dependency of a large number of marginalized people for their livelihood (Moslehuddin et al., 2018; Byron and Arnold 1999). Supporting additional people to take refuge, as a result of violence in a neighboring country, seems to have aggravated current deforestation rate (Alam et al., 2014), particularly in an environmentally fragile ecosystem zone.
Close inspection of LULC maps (Fig. 2a) indicated the distribution of degraded forests in the study area but its extent was low, prior to influx. Although forest resources in the peninsula are primary source of livelihoods for local people (Tani and Rahman, 2018), influx of Rohingya intensified process of degradation that led to severe deforestation (Fig. 2 b c). Loss of forest continued since then as depicted by Fig. 2 (b c), suggesting a loss of 1600 2200 ha in 2018 and 3200 ha in 2019. These findings are in accord with previous works (Rashid et al. 2020; Ahmed et al. 2019; Hassan et al. 2018) despite there are differences in terms of data and methods. Figure 2 (a-c) also illustrated Rohingya makeshift camps and increasing number of deforested and degraded vegetation patches, especially in close proximity to camps. A similar observation is made in Pakistan (Lodhi et al. 1998), Malawi (Babu and Hassan, 1995), Sudan (Hagenlocher et al. 2012) and Nepal (Birendra and Nagata, 2006) that deforestation increases substantially in the event of a sudden humanitarian crisis like Rohingya. Further, it is important to note that greater increase of fuelwood collection by the Rohingya communities resulted not only in clearing of forest in around the camps but also exposing top soil in the surrounding environments which can be highly detrimental. Field works as well as a previous work (Moslehudding et al., 2018) support this observation that top soil is being exposed due to pulling of remnant of trees, and such practice is albeit unhealthy for nutrient cycle of the forested ecosystem (Chen and Li, 2003).
As illegal logging and fuelwood collection are two important activities by the Rohingya communities at present, the extent of forest cover degradation is increasing over time (Table 5, Fig. 4). This type of deterioration is affecting biomass and carbon stock of the area (Table 9) which could enhance global warming (Panja, 2020). Because of forest clearance, for instance, land surface temperature (LST) of the study area increased significantly from pre to post influx (Rashid et al. 2020), a very influential factor that affects local climate variability (Wang et al. 2012). As release of carbon to the atmosphere could expedite global warming, additional loss of forest cover potentially can lead to change in regional climatic system (Bonan, 2008).
Since mixed forest, and canopy forest play an important role in ecosystem functioning, particularly in the study area, their influence on the loss of AGB is noteworthy than shrubs and planted young tree covers. It is also observed that 27,600 tons of carbon may have released to the atmosphere between 2017 and 2019 which may increase to about 71,920 tons in the future as showed by prediction. In addition, fragmentation of forest patches due to intensified pressure on resources can have profound impact on wildlife habitat. For example, there were two active elephant corridors within the study area, including multiple routes for their movement, prior to Rohingya influx (Motaleb and Ahmed, 2016). Widespread fragmentation of forest covers however reduced the extent of their habitat, causing restricted movement of the Asian elephant (Eliphus Maximus ) between adjacent habitats of ‘Teknaf Shilkhali Whykheong Inani Ukhia Ghundhum Myanmar’ and ‘Dhoapalong Himchari Panerchara Rajarkul Naikhongchari’ (Motaleb and Ahmed, 2016). As a result, thirty eight elephants were trapped inside Cox’s Bazar Teknaf peninsula (National Geographic, 2018), often leading to human elephant conflicts (UNHCR & IUCN Bangladesh, 2018). Evidence suggests that human elephant conflict increased to a greater number in recent times that caused killing of 13 people since August 2017 (McVeigh and Peri, 2018; UNHCR & IUCN Bangladesh, 2018). Further, an increase of fuelwood consumption decreases fodder for elephant species, which is an utmost sign of deterioration of overall ecosystem health. Furthermore, unwise harvesting of forest biomass can jeopardize human wellbeing and ecological sustainability (Vogt et al. 2007 cited in Panja, 2020).
Based on population, physiography, accessibility and other factors (Table 3), this study predicted forest cover scenario for 2023 and 2027 (Fig. 4, Table 7) which revealed that, if current deforestation rate continues and no more Rohingya population is added further, the extent of degraded forest could increase to 3080 ha and 5120 ha, compare to 2019. This can enhance deterioration of ecosystem function and services in the study area, urgent actions are therefore warranted.
The findings of this work are generally aligned with observations across various settings of the world that the impact of refugees on the local environment can be staggering (Hagenlocher et al. 2012; Ndyeshumba, 2000), though primary outcome can be widespread deforestation (Black, 1994). Loss of natural resources is expected to continue in the coming years since repatriation is in halt despite many attempts of the host country, Bangladesh. Since the study area is very prone to landslide, further disappearance of forest cover would not only detrimental to environmental degradation but can lead to frequent slope failures, which may put both Rohingya and local communities at extreme risk of landslide hazards (Ahmed et al. 2020). As Rohingya populations (currently 932,940) in the study area outnumbered local population of 471,768 (BBS, 2011), various issues, besides environmental degradation, are often reported including social conflict between the two competing groups. We assert that the findings of this work can contribute significantly to devise strategies for conserving and managing forest ecosystem of an ecologically critical area. Hence, government of Bangladesh (GoB) and development partners can prioritize ecosystem management to promote ecological sustainability in the study area.