Yiling Yang

Landscape aesthetic quality (LAQ) is a vital cultural ecosystem service in global forests, particularly in the subalpine forests across the Tibetan Plateau, which are considered popular tourist destinations due to their unique cultural services. However, the explicit spatial localization and spatial–temporal dynamics of LAQ in subalpine forests in the Tibetan Plateau remain largely unexplored. Herein, we introduced a method for assessing LAQ that integrates the species’ biophysical attributes with spatial landscape characteristics, allowing for a spatially explicit quantification of LAQ. We further employ this approach to project changes in LAQ under forest landscape dynamics (2016–2096) in Jiuzhaigou, eastern Tibetan Plateau. Most regions exhibited moderate or low LAQ, with high values ible, while over half of low-LAQ regions were not. The high-value zone of LAQ is projected to rise slightly by 2056 but decline sharply by 2096. These results reveal strong spatial heterogeneity in LAQ and indicate that future landscape dynamics will substantially reshape its distribution in the subalpine forests of the eastern Tibetan Plateau. Our findings provide early evidence of declining cultural ecosystem quality in subalpine forests and offer guidance for adaptive management in similar mountain ecosystems worldwide.

Agroforestry systems (AFS) are priority semi-natural ecosystems in fragile ecological zones. The complexity and diversity of their species structure play a crucial role in maintaining AFS stability. To explore the optimization of improvement strategies in AFS’ structure and stability for control of karst desertification (KD), in this study, we chose typical desertification control areas in the southern China karst region. The study included homegarden (HG), agrisilviculture (ASV), and multipurpose woodlots (MWLs) as three AFS. We quantified the AFS’ structural characteristics using descriptive statistics and spatial structure parameters. We used the fuzzy integrated evaluation method with structural and functional indicators as guidelines, and stand structure, plant species diversity, soil fertility, and environmental factors as first-level evaluation indicators. The entropy weight method calculates the weights of indicators at all levels. The fuzzy comprehensive evaluation method establishes an evaluation index system to evaluate the grading of AFS’ stability. The results showed that: (i) The species composition of the AFS in the KD control areas had a simple structure, the overall diversity level was low, and the diversity level of herbaceous plants was better than that of woody plants. (ii) The overall distribution curves of diameter at breast height (DBH), tree height (TH), and crown width (CW) of woody plants in the AFS in the KD control areas were slight to the left, with a single-peaked pattern, mostly randomly and unevenly distributed in space, with a low degree of tree species isolation and relatively weak stand stability. (iii) There was variability in the stability classes of different types of AFS, overall reflecting the ranking HG > ASV > MWLs. (iv) When structural optimization was applied, corresponding measures can be taken according to farmers’ wishes for different types of AFS and their primary business purposes. The improvement of stability depends mainly on the utility of the structural optimization applied coupled with positive human interference (for example, pruning, dwarfing, and dense planting). This study provides a scientific reference for maintaining the stability of AFS and promoting service provision.