## 4 Conclusions  
This study quantified the GPP rates in the forests of the Macao municipality and related them with the severity of wildfires for a period of nearly three decades. The high and moderate classes of NDVI, corresponding to about 80% of the area of Macao, before the fires of 1991, 2003, 2017 and 2019 revealed the existence of a high vegetation cover prior to the fires. In 1991, the cover was essentially _Pinus pinster_ Ait. After the fires, the vegetation cover recovered mainly in the form of shrubs and _Eucalyptus globulus_ Labill. ;  
Figure 6: Spatial distribution of GPP before and after the wildfires of 2003, 2017, and 2019.  
this was a consequence of the abandonment of forestry activities and management that followed the sharp decrease in population in the municipality. Severity analysis showed that fires tend to be more severe and extensive when biomass is denser, i.e., with more combustible vegetation and with continuous spatial distribution. The wildfires of 2017 and 2019 together practically consumed the entire municipality. The GPP models showed that, before the wildfires, the forested area of Macao was a large carbon sink, with average values of 5.4 and 5.3 gC/m\({}^{2}\)/day on 10 July 2002 and 14 June 2017, respectively. On 29 May 2019, GPP was slightly lower, reaching 4.7 gC/m\({}^{2}\)/day. After the fires of 2003 and 2017, GPP values in the burnt area reached an average value of 1.2 gC/m\({}^{2}\)/day, showing evidence of a nonautochthonous forested area with low resilience to fire. The 2019 fires burnt an area that had previously been unaffected by fire during the three decades under analysis. On 1 August 2019, this area had an average GPP of 2.1 gC/m\({}^{2}\)/day, again showing that an older forest has greater resilience to fire. In the future, in the medium- and long-term, the regeneration capacity of the vegetation may be compromised in the case that fires become increasingly recurrent and intense, as there would be no time to restore the _Pinus pinaster_ Ait. seed bank. Carbon sequestration in vegetation can also considerably decrease if the _Pinus pinaster_ Ait. forest is extinguished and replaced by shrub or _Eucalyptus globulus_ Labill. The municipality of Macao faces the important challenge of attaining proper forest management and land-use planning to prevent and mitigate the consequences of wildfires. It is necessary to reduce biomass and disconnect forested areas rich in combustible plants, namely, shrubs, _Eucalyptus globulus_ Labill., and _Pinus pinaster_ Ait. Optting for pastoral practices and the planting of native trees, such as _Castanea sativa_ [PERSON], _Quercus figinea_ [PERSON], and _Quercus suber_ L. can be an important aid to increase resilience to wildfires in this area of Portugal. Regarding the economic value generated by forests, it is important to boost forestry associations. This would help to gather currently fragmentated small properties in units of an adequate size to be properly managed. The introduction of recreational activities may also contribute to reaching the economic sustainability of forests that can be compatible with the conservation of biodiversity and the defence of forests against wildfires. Future research in this theme will include analysis of the increase in GPP once the vegetation begins to recover. This will allow for gaining better insight on the relation between vegetation growth and GPP. **Supplementary Materials:** The following are available online at [[https://www.mdpi.com/article/10.3390/su13115816/s1](https://www.mdpi.com/article/10.3390/su13115816/s1)]([https://www.mdpi.com/article/10.3390/su13115816/s1](https://www.mdpi.com/article/10.3390/su13115816/s1)), Figure S1: Analysis of residuals according to (a) homogeneity of variance, (b) normality, (c) independence, and (d) Cook's distance, for the linear models before and after the wildfires of 2003, 2017 and 2019. **Author Contributions:** Conceptualization, H.M.F., F.M.G.-M., P.F. ; methodology, H.M.F., F.M.G.-M., C.M.G.P., P.F. and J.M.G.P.I. ; software, H.M.F.