LAI Mapping of Winter Moso Bamboo Forests Using Zhuhai-1 Hyperspectral Images and a PSO-SVM Model

Forests, Journal Year: 2025, Volume and Issue: 16(3), P. 464 - 464

Published: March 6, 2025

Moso bamboo forests (MBFs) are unique subtropical ecosystems characterized by distinct leaf phenology, shoots, rapid growth, and carbon sequestration capability. Leaf area index (LAI) is an essential metric for evaluating the productivity ecological quality of MBFs. However, accurate large-scale methods remote-sensing-based LAI monitoring during winter growth stage remain underdeveloped. This study introduces a novel method integrating hyperspectral indices from Zhuhai-1 Orbit Hyperspectral Satellites (OHS) imagery with particle swarm optimization-support vector machine (PSO-SVM) coupling model to estimate in Five traditional vegetation (VIRs) their red-edge variants (VIREs) were optimized build empirical models. Machine learning algorithms, including SVM, Random Forest, extreme gradient boosting, partial linear regression, also applied. The PSO-SVM model, three VIRs VIREs, achieved highest accuracy (R2 = 0.721, RMSE 0.490), outperforming approaches. was strongly correlated indices, such as NDVIR, RVIR, EVIRE, SAVIR (R > 0.77). values MBFs primarily ranged 2.1 5.5 winter, exceeding 4.5 indicating high shoot harvesting. These findings demonstrate potential OHS data improve retrieval models mapping, offering new insights into contributing sustainable forest management practices.

Language: Английский

Ecological Restoration Increases the Diversity of Understory Vegetation in Secondary Forests: An Evidence from 90 Years of Forest Closures

Forests, Journal Year: 2024, Volume and Issue: 15(9), P. 1642 - 1642

Published: Sept. 18, 2024

Ecological restoration and biodiversity are currently hot issues of global environmental concern. However, knowledge about the specific impacts duration on understory vegetation diversity remains limited. Therefore, this study comprehensive employed a spatial approach to compare differences in plant species composition among secondary forests with varying ecological ages (0, 10, 30, 60, 90-year-old stands) Huangfu Mountain National Forest Park. This methodology allowed us clarify key factors affecting community investigate regulatory mechanisms influencing changes diversity. The results showed that shrub Shannon’s index value, evenness, herb richness, evenness were significantly affected by years restoration, 10 90 being highest 60 lowest. Substrate was main factor layer. Overstory soil C/N, C, N, bacterial Observed OTUs, Chao1, Pielou_e, substrate drivers had direct effect (0.256) an indirect (0.284) through light availability fungal Simpson’s value. Light directly negatively (−0.360). In addition, 52.6% from arboreal layer availability, To sum up, moderate disturbance environment natural can be carried out after which is more conducive increase provides theoretical basis for formulating measures forests, particularly understanding optimal timing nature process, reassuring audience validity reliability findings.

Language: Английский

The Impact of Bamboo (Phyllostachys edulis) Expansion on the Water Use Patterns of Broadleaf Trees

Forests, Journal Year: 2024, Volume and Issue: 15(11), P. 1984 - 1984

Published: Nov. 10, 2024

The expansion of bamboo (Phyllostachys edulis) affects the growth status trees in colonized forests, but there has been insufficient research on changes tree water physiology. In this study, we used stable δ2H, δ18O, and 13C isotope ratios to analyze sources use efficiency (WUE) bamboo, deciduous broadleaf (Alniphyllum fortunei), evergreen (Machilus pauhoi Castanopsis eyrei) a bamboo-expended forest (BEBF), bamboo-absent (BABF), (BF). We found that had no significant effect WUE trees, altered trees. During growing season, decrease their uptake fractions surface soil by 7.1% 9.6% increased middle 5.8%~9.4%. Conversely, during non-growing they 11.9% decreased deeper 5.6%~12.9%. Additionally, after expanding into its proportion shallow 20.0% 9.4% season. Its also improved, increasing 20.0 μmol/mol 13.0 seasons, respectively. These results indicate as expands it enhances competitiveness for resources changing strategy. Compared exhibit more flexible strategies under conditions expansion. Our reveals, first time, how adjust response expansion, uncovers mechanisms behind forests from perspective strategies. This will aid future management

Language: Английский