The unchecked and unplanned expansion of urban areas has led to the conversion of millions of green areas to gray areas. The recent urban growth patterns of Pakistan’s metropolitan twin cities, Islamabad and Rawalpindi, is a matter of concern for the surrounding green areas. The present study aimed to categorize and quantify the land-use and land-cover change (LULCC) patterns and the corresponding impacts on the forest carbon dynamics around Islamabad and Rawalpindi. Multispectral satellite images for the year 1990 (Landsat 5 TM) and 2020 (Landsat 8 OLI) were used to determine, quantify, and compare the LULCC inside and around the twin metropolitan cities. Field inventory surveys in the reserved forests of Rawalpindi and Islamabad were also conducted to determine the amount of stored carbon in these forests. Our results showed an accelerated annual urban expansion (i.e., an increase in the built-up area) of 16.49% and 26.72% in Rawalpindi and Islamabad, respectively, during the study period. Similarly, the amount of barren land and agricultural land was reduced at an annual rate of 2.08% and 2.18%, respectively, in Rawalpindi and 0.25% and 1.04% in Islamabad. A reduction in the area of barren mountains also occurred at an annual of 2.26% in Islamabad, while it increased by 4.16% in Rawalpindi. The amount of carbon stored in the reserved forests of Islamabad stood at 139.17 ± 12.15 Mg C/ha while that of Rawalpindi was 110.4 ± 13.79 Mg C/ha. In addition, total stored forest carbon was found to have decreased from 544.70 Gg C to 218.05 Gg C in Rawalpindi, while in Islamabad it increased from 2779.64 Gg C to 3548.16 Gg C. Investment in ecological urban planning, sustainable cities, and appropriate land-use planning is recommended to curb the degradation and conversion of the surrounding green areas of Rawalpindi and Islamabad.

Protected areas serve two objectives, biodiversity conservation and securing of ecosystem services. But the recent expansion of human activities around Cameroon’s Rumpi Hills Forest Reserve in this Era of Sustainable Development Goals is a call for concern. This study assesses land use and land cover change around the reserve and their potential impact on its sustainability. A total of 250 household surveys were conducted across 13 villages in four selected sites around the reserve in addition to 11 focus group discussions. Landsat 7 ETM (2000) and Landsat 8 OLI (2014) images and topographic maps were utilized to quantify land use and land cover change. During the 14-year period, dense forest dropped to 90.2% while settlements increased from 744.6 to 2148.8 hectares in 2014. Also, farmlands increased by 18.25% representing a change from 9400.4 to 11117.16 hectares. Over 98% and 85% of the respondents are engaged in the cultivation of food and cash crops and are dependent on the forests for timber and non-timber forests products. Land and tree-based interventions that improve soil fertility should be promoted among smallholder farmers to ensure the sustainability of protected areas in Cameroon.

Monitoring and mapping forest carbon is critical for informing climate change mitigation measures. Evidence indicates that forest edges hold less carbon than the forest interior. In this study, using field inventory data from a Chinese fir forest ecosystem in southeast China, the carbon at the forest edge and forest interior at different elevations was measured. The results showed a significant increasing trend in carbon with elevation. The results also revealed that forest edges had significantly lower carbon than the forest interior. Carbon density values varied between 265 Mg C ha⁻¹ at forest edges and 320 Mg C ha⁻¹ at forest interior. The study highlights that ignoring edge effects overestimates carbon density by 9.46%. These findings suggest that edge effects should be given proper consideration during national forest carbon inventory. Furthermore, the authors recommend the establishment of permanent sampling plots along forest edges for precise and accurate carbon accounting.