Rapid urban expansion and development have resulted in the conversion of many natural green surfaces within cities to non-transpiring built-up surfaces, such as concrete and asphalt. These artificial urban surfaces cause substantial variation in land surface temperatures that affect the urban microclimate. Thus, there is the need to substantially quantify the extent of green cover loss within growing cities and its impact on surface temperatures. This study used LANDSAT data to spatially assess the extent of urban expansion and its effect on land surface temperature within Kumasi, Ghana. Subsequently, the results showed significant changes in the land cover, which had an effect on the observed land surface temperatures from 1986 to 2015. Generally, there was an overall increase in the built-up areas by 24.13% (55.81 km²) from 1986 to 2015, with a corresponding increase in the mean land surface temperature by 4.16°C. As such, there is the need for the adoption of sustainable urban planning strategies with green vegetation conservation initiatives for modern city planners. This would help reduce urban land surface temperatures while promoting clean air circulation within the city.

The occurrence of extreme drought poses a severe threat to forest ecosystems and reduces their capability to sequester carbon dioxide. This study analysed the impacts of a central European summer drought in 2015 on gross primary productivity (GPP) at two Norway spruce forest sites representing two contrasting climatic conditions—cold and humid climate at Bílý Kříž (CZ-BK1) vs. moderately warm and dry climate at Rájec (CZ-RAJ). The comparative analyses of GPP was based on a three-year eddy covariance dataset, where 2014 and 2016 represented years with normal conditions, while 2015 was characterized by dry conditions. A significant decline in the forest GPP was found during the dry year of 2015, reaching 14% and 6% at CZ-BK1 and CZ-RAJ, respectively. The reduction in GPP coincided with high ecosystem respiration (R_eco) during the dry year period, especially during July and August, when several heat waves hit the region. Additional analyses of GPP decline during the dry year period suggested that a vapour pressure deficit played a more important role than the soil volumetric water content at both investigated sites, highlighting the often neglected importance of considering the species hydraulic strategy (isohydric vs. anisohydric) in drought impact assessments. The study indicates the high vulnerability of the Norway spruce forest to drought stress, especially at sites with precipitation equal or smaller than the atmospheric evaporative demand. Since central Europe is currently experiencing large-scale dieback of Norway spruce forests in lowlands and uplands (such as for CZ-RAJ conditions), the findings of this study may help to quantitatively assess the fate of these widespread cultures under future climate projections, and may help to delimitate the areas of their sustainable production.

The strong effects of climate change are expected to negatively impact the long-term resilience and function of forest ecosystems, which could lead to changes in forest carbon balance and productivity. However, these forest responses may vary with local conditions and forest types. Accordingly, this study was carried out to determine gross primary productivity (GPP) sensitivity to changes in environmental parameters. Central European beech (at Štítná) and spruce species (at Bílý Kr̆íz̆ and Rájec), growing under contrasting climatic conditions, were studied. The comparative analyses of GPP were based on a five-year-long dataset of eddy covariance fluxes during the main growing season (2012–2016). Results of forest GPP responses with changes in environmental factors from a traditional Stepwise multiple linear regression model (SMLR) were used and compared with Random forest (RF) analyses. To demonstrate how actual GPP trends compare to potential GPP (GPP_pot) courses expected under near-optimal environmental conditions, we computed normalized GPP (GPP_norm) with values between 0 and 1 as the ratio of the estimated daily sum of GPP to GPP_pot. The study confirmed the well-known effect of total intensity of the photosynthetically active radiation and its diffuse fraction on GPP_norm across all the forest types. However, the study also showed the secondary effects of other environmental variables on forest productivity depending on the species and local climatic conditions. The reduction in forest productivity at the beech forest in Štítná was presumed to be mainly induced by edaphic drought (anisohydric behaviour). In contrast, reduced forest productivity at the spruce forest sites was presumably induced by both meteorological and hydrological drought events, especially at the moderately dry climate in Rájec. Overall, our analyses call for more studies on forest productivity across different forest types and contrasting climatic conditions, as this productivity is strongly dependent on species type and site-specific environmental conditions.

This study examined the impacts of climate variability and cultivated land area on the yields of cassava, yam, and maize in Wenchi Municipality, Ghana, from 2000 to 2021. Using a quantitative approach, the study employed time-series data on rainfall, minimum and maximum temperatures, crop yields, and cultivated area. Multiple linear regression models with logarithmic transformations were used to assess the influence of climate variables and cultivated area on crop yields. Diagnostic tests confirmed the validity of model assumptions. The regression results revealed that temperature variables, especially minimum temperature, had a significant positive effect on all three crop yields. Maximum temperature also showed positive effects, although with varying levels of significance. Rainfall and cultivated area had no statistically significant impact on yields. The models explained 46.87%, 51.28%, and 61.57% of the variations in cassava, yam, and maize yields, respectively. Temperature played a more critical role than rainfall or cultivated land in influencing crop yields in Wenchi over the study period. These findings underscore the need for temperature-focused adaptation strategies and climate-smart agriculture to enhance food security and resilience in the transitional zones of Ghana.