Understanding plant phenological responses to climate warming is crucial for predicting changes in plant communities and ecosystems but difficult with sensitivity analysis that is not linked to drivers of spring phenology. In this article, we present a new measure phenological lag to quantify the overall effect of phenological constraints including insufficient winter chilling, photoperiod, and environmental stresses, based on observed response and that expected from species-specific changes in spring temperatures, i.e., changes in spring forcing (degree days) from warming and average temperature at time of species events. We applied this new analytical framework to a global dataset with 980 species and 1527 responses to synthesize observed changes in spring phenology and investigate the contributions of forcing change, growth temperature, and phenological lag to differential phenological responses reported previously.

Cupressus funebris Endl., a widely cultivated evergreen species in China, plays an important ecological and economic role in afforestation, ecological restoration, and the production of essential oils and medicinal compounds. However, its taxonomic status within Cupressaceae has long been debated due to complex phylogenetic relationships. In this study, we sequenced and annotated the complete chloroplast genome of C. funebris and conducted comparative analyses with nine other Cupressaceae species. The genome of C. funebris is 127,816 bp in length, encoding 117 genes. Comparative analyses revealed a highly conserved genome structure across the ten species, with notable divergence concentrated in coding regions such as accD, ycf1, ycf2, and rpoC2. Codon usage analysis indicated a significant bias toward codons ending in A or U. A total of 709 simple sequence repeats (SSRs) and 170,475 single nucleotide polymorphisms (SNPs) were identified, providing valuable markers for genetic studies. The phylogenetic tree constructed from 63 complete chloroplast genomes revealed species relationships largely consistent with traditional taxonomy, indicating that chloroplast genomes can effectively reflect phenotypic variation within Cupressaceae and thus hold broad potential for systematic and evolutionary studies. Furthermore, variable regions within the rpoA and rpoC2 genes were identified as SNP-rich hotspots, enabling species-level discrimination across all ten species. These findings not only enhance our understanding of chloroplast genome evolution in Cupressaceae but also offer genomic resources for taxonomy, phylogenetics, and molecular breeding.