We assessed the effects of landscape change on the climate regulation ecosystem service in a mountain river basin of Portugal, through the quantification, valuation and mapping of carbon sequestration and storage. The analyses were based on land use and land cover (LULC) changes that took place between 1990 and 2006 and on expected changes defined by three LULC change scenarios for 2020. We used the Integrated Valuation of Ecosystem Services and Tradeoffs model for scenario building and carbon assessment and valuation, and several modelling tools to assess past, current and future carbon in four different pools. Soil organic carbon data was obtained through an extensive sampling scheme across the entire study area. Recent (1990–2006) and expected landscape changes (2006–2020) affected considerably carbon sequestration and storage. Observed landscape changes generally promoted carbon sequestration and storage, and had a positive effect on the climate regulation ecosystem service, both biophysically and economically. Expected LULC changes further extend the capability of the landscape to increase carbon sequestration and storage in the near future. The carbon sequestered and stored in vegetation and soil contributes to avoid socio-economic damages from climate change, while increasing the economic value of particular LULC classes and the whole landscape. These results are essential to inform land planning, especially on how, where and when changes in landscapes may affect the provision of the climate regulation ecosystem service.

Wildfires can cause serious imbalances in ecosystems, primarily at the soil level, making it vulnerable to degradation processes such as erosion. During and after a fire, changes occur in soil properties, including pH, which affects the solubility and availability of nutrients. Currently, there is a great diversity of protocols, some involving normalized standards, to determine soil pH, but there is no consensual or universal analytical method for this parameter, especially in burned soils, in which mineral and organic fractions could have been modified. Therefore, the objective of the present work is to evaluate the effect that variations in these analytical protocols may have on pH results. For this, five methods commonly found in the international bibliography for the analysis of pH of soil in water (pH_H2O) were selected and compared to propose the most precise procedure. The analytical methods were applied to 43 soil samples, collected in a plot subjected to prescribed burning in the Parque Natural de Montesinho (Northern Portugal). The studied methods differ in the following protocol items: water suspension ratio (1:2.5 or 1:5), mechanical stirring time in the suspension (10 min or 1 h), and in the resting time for the solid particles to settle (15 min or 8 h). The obtained results point to the suitability of the five methods used for soil pH analysis, indicating that there are no statistically significant differences. However, results also allow suggesting a more appropriate method concerning practical reasons, such as labor in a lab. Thus, to make the analysis process more profitable, M2 is a good option because it uses a small amount of sample (5 g), short agitation (10 min) and settling time (15 min). In turn, M1 and M5, which use a lower proportion of soil (1:2.5) show lower pH variation in the measurements. This fact may be explained by a smaller dilution effect. Considering that these two methods differ in the settling time, it is suggested to apply M1, because only 15 min are required. Therefore, the main conclusion reached with this work is that the measurement of soil pH using M1, i.e., a soil:water ratio of 1:2.5, with agitation of 10 min and settling time of 15 min, is a robust and more expeditious protocol to be applied to soil samples after a fire.