Abstract Chinese trees adapted to wet, warm, highly heterogeneous, and dynamic light environments might be expected to systematically differ from other non‐Chinese trees based on stem allometry and life em allo. However, our understanding of the extent to which how differentiation in forest architecture and species size influences tree allometry relates to fundamental physiological and ecological trade‐offs, climate, forest structure, and function is limited. We quantified height–diameter allometries and growth increments of 13,594 individuals of 151 tree species across China. Although trees grew statistically indistinguishably from the theoretically predicted exponent, the height–diameter allometries for trees in China deviated from tree patterns in other continental forests worldwide. Chinese trees showed substantially lower heights at a given diameter for larger trees and asymptotic heights (33.05 m), with values were 5.5% to 43.3% lower than those estimated for continental rain forest trees in South America, Australia, Southeast Asia, and Africa. In total, 149 of 151 species showed significant nonlinearity of height–diameter allometry with asymptotic heights ranging from 6.33 to 50.54 m; additionally, half (74/149 species) fell in the range of 20–33.5 m, averaging 21.98 ± 8.70 m (SE) for canopy trees. In subsets of canopy trees sampled from larger‐statured species and deciduous trees, the approximated maximum heights were 14–42% larger than those of smaller‐statured and evergreens and those in other wet and warmer regions found worldwide. These results suggest flexible phenotypic responses of height–diameter allometries to heterogeneous light conditions along understory‐canopy gradients. Average growth rates, varying from 0.02 to 0.78 cm/yr (mean of 0.25 cm/yr), were positively related to the asymptotic height, diameter at inflection, and allometric intercept but negatively correlated with the shape of the asymptotic curve and allometric slope. Species with asymptotic heights above 30 m or inflection sizes larger than 20 cm clearly depicted higher growth rates than smaller ones.

Plant accumulation of heavy metals (HMs) has become a global concern, however, the bio-accumulation distributions, their inter-correlations, and relationships with influencing factors remain unknown at the national scale in China. Here, we investigate the bio-accumulation capacity, as indicated as bio-concentration factors (BCFs), for chromium (Cr), cadmium (Cd), lead (Pb), copper (Cu), and Zinc (Zn) across plants growing on China (span 22 provinces) and their relationships, based on national meta-analysis of 46 publications (210 species, and 66 families). Results showed that: (1) Plants show diverse capacity of HM accumulation. About 20.6% of the plant tissue cases indicates strong phytoremediation ability for HMs (i.e., Ln BCF > 0), including 38.5% of Cd, 28.5% of Cr, 11.9% of Cu, 7.6% of Pb, and 16.6% of Zn. The families with the greatest numbers of published strong HMs phytoremediation cases are Poaceae, Asteraceae, and Brassicaceae. (2) The capacity to uptake and accumulation one of these HMs is significantly correlated with the ability to absorb the others (p <.001) for both all plants and organs but differ in strength and degree of correlations. The synergistic effect of the accumulation of these metals is more stable in stems than other parts. Leaves and roots differ significantly in metal co-accumulating strengths and enrichment patterns. (3) Experimental factors affect the HM bio-accumulation processes and bio-mediated mechanisms and responsible for substantial heterogeneous in phytoremediation effectiveness. These findings suggest that the use of plant as a soil pollution indicator and phytoremediation technique, synergistic strategies of bio-accumulation as ecological indicators and bio-mediated mechanisms for phytoremediation of polymetallic contaminated areas, with considering sensitivity of influencing factors, might have a crucial effect on the eco-service, eco-environment, and land management and could reduce material hazards by increasing bio-accumulation efficiency, or could reduce human health risk by decreasing potential intake of HMs. We argue that this meta-analysis would aid the assessment of the strength of general HM risks, the evaluation of regional soil contamination hazards and consequences, and the configuration of plant species and traits efficiently for phytoremediation potential.

We investigated the fire resistance conferred by different forest age groups (young, middle-age and mature forest) and organs (leaf, branch, and bark) of six typical tree species (Myrica rubra, Schima superba, Symplocos sumuntia, Machilus pingii, Castanopsis eyrei, and Quercus glauca) in Qingshigang national forest farm, Yanling County, Hunan Province, subtropical China. We measured morphological, physical, and chemical properties that could be used as proxies for fire resistance and examined the variances of fire resistance among different organs and age groups in the same tree species. Further, we comprehensively ranked all the tree species by their capacity in fire resistance. We found considerable variation in fire resistance among organs and age groups. Compared with branches and barks, leaves had relatively higher water content (53.7%), higher crude ash content (4.5%), and lower crude fiber content (23.9%). Fire resistance of trees decreased first and then increased with increasing stand age. Trees in middle-aged stage showed the lowest contents of water, crude ash, and crude fiber. The comprehensive scores of fire resistance for diffe-rent organs were significantly different among species. Fire resistance of leaves generally decreased in the order of M. pingii > C. eyrei > S. sumuntia > M. rubra > S. superba > Q. glauca. For branches, M. pingii and C. eyrei showed the strongest fire resistance, followed by M. rubra and S. superba. For barks, S. superba and C. eyrei were relatively stronger in fire resistance than other species, while M. pingii and Q. glauca were the weakest. The comprehensive scores of fire resistance performance of species were different. S. superba (1.033) and M. rubra (0.526) were the most fire-resistant species, while M. pingii (-0.405) and Q. glauca (-1.151) were the least fire-resistant. Therefore, S. superba and M. rubra were the preferred tree species for fire prevention forest belt in forests of subtropical southern China.