Javier de León

Environmental factors affect plant physiological processes. Understanding these factors can increase productivity, especially in tropical mountain ecosystems, where they vary with altitude. This study aimed to analyze the physiological variations related to water vapor and gas exchange in Prunus persica L. Batsch according to the altitudinal gradient in North Santander. One plant was selected per altitude, and six leaves were selected per plant and per branch across three phenological stages. Conductance (gs), stomatal resistance (SR), and transpiration (E) were determined using a calibrated portable porometer over two cycles. Linear mixed-effects models with repeated measurements over time, phenological effects, altitude, and light conditions were used. At higher altitudes, gs and E decreased and SR increased, possibly due to higher ultraviolet radiation and lower temperatures with increasing altitude. Maximum values were reached at EF6. gs and E exhibited diurnal patterns, decreasing at the end of the day to minimize water loss during periods of lower solar radiation. The cultivar adjusted its stomatal and water regulation mechanisms according to altitude. These findings provide advanced insights into plant acclimatization strategies in mountain ecosystems and inform the sustainable management practices needed in the face of impending global climate variability.

The economic valuation of sustainable policies is necessary for undertaking socially optimal decisions that reduce the adverse impacts of tourism across society and the environment. This paper focuses on the economic valuation of sustainable tourism policies based on the evidence found in the literature of discrete choice experiments (DCE). The methodology involves both a systematic critical literature review and a meta-regression analysis of tourists’ preferences and willingness to pay (WTP) for sustainable policy attributes. The findings show that tourists value policies that contribute to sustainability. However, preferences are higher for those features related to nature, the environment, and local communities and lower for those policies concerning sustainable accommodation, infrastructures, and facilities. The results show critical gaps both in terms of the available evidence of sustainable policies and the methodological pitfalls across study results. Based on this assessment, a guiding protocol is proposed for future research.