Quercus acutissima, an important endemic and ecological plant of the Quercus genus, is widely distributed throughout China. However, there have been few studies on its chloroplast genome. In this study, the complete chloroplast (cp) genome of Q. acutissima was sequenced, analyzed, and compared to four species in the Fagaceae family. The size of the Q. acutissima chloroplast genome is 161,124 bp, including one large single copy (LSC) region of 90,423 bp and one small single copy (SSC) region of 19,068 bp, separated by two inverted repeat (IR) regions of 51,632 bp. The GC content of the whole genome is 36.08%, while those of LSC, SSC, and IR are 34.62%, 30.84%, and 42.78%, respectively. The Q. acutissima chloroplast genome encodes 136 genes, including 88 protein-coding genes, four ribosomal RNA genes, and 40 transfer RNA genes. In the repeat structure analysis, 31 forward and 22 inverted long repeats and 65 simple-sequence repeat loci were detected in the Q. acutissima cp genome. The existence of abundant simple-sequence repeat loci in the genome suggests the potential for future population genetic work. The genome comparison revealed that the LSC region is more divergent than the SSC and IR regions, and there is higher divergence in noncoding regions than in coding regions. The phylogenetic relationships of 25 species inferred that members of the Quercus genus do not form a clade and that Q. acutissima is closely related to Q. variabilis. This study identified the unique characteristics of the Q. acutissima cp genome, which will provide a theoretical basis for species identification and biological research.

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Fokienia hodginsii (Dunn) Henry et Thomas is a relic gymnosperm with broad application value. It is a fit candidate when choosing species for the construction of artificial forests. We determined the complete chloroplast genome sequence of F. hodginsii, which is 129,534 bp in length and encodes 83 protein genes, 33 transfer RNA (tRNA) genes, as well as four ribosomal RNA genes. The GC content of the complete sequence and protein coding regions is 34.8% and 36.2%, respectively. We identified 11 tandem repeats, 11 forward repeats, and three palindromic repeats and classified them by size. Following our microsatellite analysis, a total number of 73 simple sequence repeats were detected, preferentially within the intergenic space. Being a member of Cupressophyta, F. hodginsii owns several common characters; the trnR-CCG gene has been deleted, while the trnI-CAU and trnQ-UUG genes have been duplicated. Moreover, the accD gene, which encodes acetyl-CoA carboxylase, contains 771 codons in F. hodginsii, similar to Cryptomeria japonica (L. F.) D. Don, further supporting the diversity of accD and its size expansion in Cupressophyta. Concerning the loss of inverted repeat (IR) regions, the 86-bp sequence with the duplicated trnI-CAU gene is inferred to be the footprint of IR contraction. Phylogenetically, F. hodginsii is placed as a sister taxon to Chamaecyparis hodginsii (Dunn) Rushforth. This work offers meaningful guidance as well as reference value to the breeding research and improvement of F. hodginsii. Moreover, it gives us a better understanding of the genomic structure and evolutionary history of gymnosperms, especially coniferales.

Distylium tsiangii Chun ex Walker is an evergreen tree species endemic to China. It has been classified as critically endangered in the Red List of China Higher Plants. Here, we sequenced, assembled, and analyzed the complete chloroplast (cp) genome of D. tsiangii. The plastome is 159,125 bp in length, with a typical quadripartite structure and consisting of a pair of inverted repeat (IR) regions (26,220 bp) separated by a large single copy (LSC) region (87,897 bp) and a small single copy (SSC) region (18,788 bp). The overall GC content was 38.00%. A total of 131 genes were annotated, including 37 tRNA genes, 86 protein-coding genes, and eight rRNA genes. Phylogenetic analysis showed that D. tsiangii was more closely related to Parrotia subaequalis.

The Wuyi Mountains in China are one of the largest and most complete subtropical forest ecosystems at the same latitude in the world. However, our limited understanding of the function of this distinctive ecosystem means that the interrelationship between species diversity and ecosystem functioning needs to be investigated if evergreen broadleaf forests (EBLFs) are to be protected. Here, we calculated species richness, the Shannon–Wiener index, and the Pielou index in large-, medium-, and small-scale (20 m × 20 m, 10 m × 10 m, and 5 m × 5 m) forest dynamics plots (FDPs). We also investigated the interrelationships between species diversity and aboveground biomass (AGB)/productivity in FDPs at the different scales using the generalized linear regression model. The results showed that species diversity and AGB positively interrelated with each other, whereas there was no species diversity-productivity interrelationship in the subtropical BLF on the Wuyi Mountains. The structural equation model (SEM) showed that elevation was a key factor directly affecting AGB. These findings lead to the conclusion that productivity is not solely correlated with species diversity and that abiotic factors probably mediate the positive interrelationship between species diversity and ecosystem functioning. This study provides theoretical basis that can be used to protect EBLFs in subtropical areas and the results can be used to improve the construction of artificial forest communities and vegetation restoration at the same latitude.