Carexqingyuanensis (Cyperaceae), a new species from Guangdong, China.

Carexqingyuanensis, a new species of Cyperaceae from Guangdong Province, China, is described and illustrated. The new species is morphologically similar to Carexpeliosanthifolia F. T. Wang & Tang ex P. C. Li, but it can be distinguished by the racemose inflorescence branches appearing single (rarely binate or ternate) (vs. binate or ternate), one (rarely two or three) (vs. 1-3) spiked, male part of linear-cylindrical spikes much longer than the female part (vs. just male part short-cylindrical and slightly longer than female part), style base thickened (vs. not thickened) and perigynium horizontally patent with a short (vs. long and excurved) beak. Phylogenetic analysis, based on the two nuclear DNA regions (ETS 1f and ITS) and three chloroplast DNA regions (matK, ndhF and rps16), suggests that the new species belongs to sect. Siderostictaes.s. of subg. Siderosticta and shows a closer phylogenetic relationship to Carexscaposa C. B. Clarke.

Carbon storage capacity of Castanopsis hystrix plantations at different stand-ages in South China.

The establishment of forest plantations is an excellent silvicultural alternative to improve atmospheric carbon (C) sequestration for climate change mitigation. In recent years, the importance of forest growth and C dynamics at different stand ages have drawn huge attention for investigation. To evaluate the impacts of different stand ages on the C storage capacity of Castanopsis hystrix plantations ecosystems, we measured biomass and C content in trees, understory, litter, and soil components from field measurements at different stand ages, i.e., 6-, 10-, 15-, 25-, and 34-year-old stands. Results showed that the C stocks in trees, understory vegetation, litter, soil and the whole ecosystem increased steadily with stand age. C. hystrix C storage capacity in the 6-, 10-, 15-, 25-, and 34-year-old stands were 29.17, 56.18, 85.60, 132.19 and 157.79 Mg ha-1, respectively, while the total ecosystem C storage capacity was 68.11, 106.11, 136.13, 187.34 and 226.14 Mg ha-1, respectively. Meanwhile, the C sequestration rate in the 6-10, 10-15, 15-25 and 25-35-year-old stands were 675.28, 588.35, 465.97 and 284.39 g m2 year-1, respectively. Similarly, total biomass of trees, understory, and litter increased with stand age. Our study indicated that C. hystrix plantations are still developing in the area, since live biomass and soil C continue to accumulate despite reduced C sequestration rates. The information provided here highlight the C stock and C sequestration rates of C. hystrix at different stand ages, providing baseline information on the C dynamics of young and older stand of C. hystrix in this region; Hence, such knowledge could be useful for designing more realistic policies to mitigate climate change, such as programs to maintain continuous forest growth.

Commelinadanxiaensis (Commelinaceae), a new species from Guangdong, China.

Commelinadanxiaensis (Commelinaceae), a remarkable new species from Mount Danxia, Guangdong Province, China, is described and illustrated. This species is similar to C.communis in inflorescences and flowers but readily distinguishable in its nearly erect stems, larger flowers, and different petal colouration.

DPTF: a database of poplar transcription factors.

The database of poplar transcription factors (DPTF) is a plant transcription factor (TF) database containing 2576 putative poplar TFs distributed in 64 families. These TFs were identified from both computational prediction and manual curation. We have provided extensive annotations including sequence features, functional domains, GO assignment and expression evidence for all TFs. In addition, DPTF contains cross-links to the Arabidopsis and rice transcription factor databases making it a unique resource for genome-scale comparative studies of transcriptional regulation in model plants. Availiability: DPTF is available at http://dptf.cbi.pku.edu.cn.