Abstract:This review introduced the general theories on restoration ecology, especially on vegetation restoration theories. The target of vegetation restoration is to reconstruct the reasonable structure, function and dynamic processes of vegetation ecosystems, for improving/optimizing ecosystem services. The climax in the region can be taken as the reference ecosystem for vegetation restoration, but only part of the composition, structure, and function were restored in practice. Most of the vegetation restoration studies were focused on the causes and processes of degradation, and processes and mechanisms of restoration/reconstruction, companied with restoration practices on habitation, population, community, ecosystem and landscape scales. Based on a statement of problems in current vegetation ecosystems in southern China, a systemic review was given out about the vegetation restoration in southern China, especially the vegetation restoration researches carried out by South China Botanical Institute (Garden). Finally, the trends of vegetation restoration researches and practices in southern China were pointed out.

Abstract:Soil organic carbon (SOC) is an important asset of ecosystems and plays a key role in the global carbon balance. Since the 2015 Paris Climate Conference, promoting SOC accumulation in terrestrial ecosystems has received special attention and is considered to be the most important land-based action of mitigating the rising atmospheric CO₂ concentration. Starting from serving this goal, this paper reviews and summarizes the history of the global exploration of SOC formation mechanisms over the recent decades. Including the global distribution law of SOC, the SOC cycle processes and the corresponding physical, chemical and biological mechanisms at scales that are smaller than plot, and the mechanisms of soil carbon sequestration at scales that are larger than plot. Finally, an example of the SOC accumulation mechanisms of mature forest is given. So, the exploration process of the SOC formation mechanisms is actually the process of seeking theoretical guidance for promoting soil carbon sequestration.

Abstract:Acidic forest soils are highly weathered with low pH and base saturation (BS), and thus a weak acid buffering capacity. However, whether or not these acidic forest soils can continue buffering elevated anthropogenic acid deposition remain largely unknown and controversial. The acidification processes in acidic forest soils from domestic and foreign studies were reviewed, aiming to advance people's understanding of the response patterns and key buffering mechanisms of acidic forest soils to elevated anthropogenic acid deposition. The adverse effects of acid deposition-induced soil acidification in forest ecosystems will be predicted and disposed, and some references to forest management and maintaining the stability of those affected forest ecosystems and their services were also provided.

Abstract:Human activities, such as combustion of fossil fuel, production and application of nitrogenous fertilizer, and intensive livestock production, have been accelerating the production and emission of reactive nitrogen (e.g., NH₄⁺, NO₃^-), leading to elevated nitrogen (N) deposition at regional and global scales. Human interference with N cycle has gone beyond the safe operating space for humanity. China is one of the three regions with the highest N deposition in the world. High N deposition has threatened the health and safety of terrestrial ecosystems, which should be addressed urgently during the process of ecological civilization construction. The research history on simulated N deposition in China and world was reviewed, focused on how simulated N deposition affects forest ecosystems in China, including soil acidification, plant element chemistry, plant growth and diversity, soil microbial community and enzyme activities, soil fauna, greenhouse gas emissions, ecosystem N and phosphorus cycles, soil N transformation, ecosystem N fixation, litter decomposition, and ecosystem carbon sequestration. The atmospheric N deposition has been concerned since 2000s. In 2002, the first long-term forest ecosystem N manipulative experiments were established by South China Botanical Garden (SCBG) of the Chinese Academy of Sciences, which is playing a leading role in the field of nitrogen deposition and forest ecosystems in China. In 2013, SCBG, for the first time, designed a novel experiment with canopy addition of N (CAN) vs. understory addition of N (UAN) in China. Results from N manipulative experiments across China showed that continuing high N deposition greatly altered forest structure and functioning, threatening ecosystem health, especially in the south-central China. The main results are as follows:(1) There is a fertilization effect of N deposition in temperate and boreal forests, but there seem no positive effects on plant growth in N-rich tropical forests because of N saturation. (2) Excess N deposition can lead to soil acidification and nutrient imbalance. (3) Elevated N deposition has accelerated N cycling rate and its transformation process, but depressed ecosystem N fixation rate, and altered ecosystem P availability and cycling, litter decomposition process and greenhouse gas emissions. (4) High N deposition reduced understory plants diversity and changed the structure of soil microbial community. (5) Nitrogen deposition generally simulates aboveground vegetation C sequestration across China, but there remains uncertain on belowground soil C sequestration. (6) Tropical and subtropical forest ecosystems are non-ignorable N sinks, depending on the forms and fates of added N. (7) The effects of N deposition on forest ecosystems are variable, depending on ecosystem N status, land-use history, climate, and forest types and ages. Considering that there remain uncertainties on the long-term effects of N deposition in China, it is suggested that it is necessary to continue the present studies in a longer term, and to expand a network research among field sites along climate gradients. It would be further highlighted to explore how forest ecosystems respond and acclimate to long-term N inputs, to quantify belowground C and N sequestration, and to jointly consider multiple global change factors (e.g., climate warming, CO₂ enrichment, changes in precipitation patterns), all of which are important for forest management and sustainable development in the future.

Abstract:Plant functional traits (PFTs) are plant attributes that can reflect plant life history processes, such as carbon acquisition, water transport and nutrient cycling, including plant features associated with plant physiology, morphology and phenology. Employing functional traits to answer questions regarding plant distribution, growth and survival, as well as to explore the mechanisms underlying plants' response to global climate change, remains a hot research topic in ecology over the past decades. However, it has been shown that trait-trait correlation and its association with environmental factors are rather variable or even reverse across ecological scales. The research progresses related to PFTs at different scales, i.e., within species, across species, across communities and across biomes globally were summarized. The limitations of current research of PFTs and proposed future research directions in this field were also discussed.

Abstract:Ecological stoichiometry theory was first used in the research of aquatic ecosystem, but in recent 20 years, a large number of researches associated ecological stoichiometry particularly plant N/P stoichiometry under global change have been carried out in the terrestrial ecosystem, which greatly enriched and enhanced our understanding of the processes of terrestrial plants, including ecosystems ecological processes. The research status of terrestrial plant ecological stoichiometry in the context of global change was reviewed. At the same time, taking the 90th anniversary of South China Botanical Garden, Chinese Academy of Sciences as an opportunity to summarize our research work on the ecological stoichiometry of subtropical forest plants in South China, and further analyze some existing problems and propose the development focus on future research, with a view to promote and push research in the field of ecological stoichiometry in our garden or China.

Abstract:Global changes impose a profound impact on the xylem formation, which in turn affects the carbon sequestration of forest ecosystems and fundamental services of global ecosystems. The xylem formation dynamic of tree is mainly characterized by the timing of the onset and the end of cambial activity, the length of the growing season, and the growth rate, etc., which are jointly regulated by various factors, such as phytohormone, carbohydrate, nitrogen and meteorological factors. By investigating the formation dynamics of xylem over a fine time scale, the determinants of xylem formation could be revealed, the understanding of physiological mechanism of tree growth would be deepen, and the prediction accuracy of the tree growth response to climate changes would further improve. The recent research progresses in the xylem formation dynamic and its regulation mechanism were reviewed, and the prospects for the future research were provided.

Abstract:Based on molecular phylogenetic evidences, the classification of Gesneriaceae was dramatically changed in recent years. Especially, many genera in the Old Word have been systematically rearranged. However, cytological data of Gesneriaceae have not been re-examined. The cytological data of the Old Word Gesneriads, obtained from WebCyte database, Chromosome Counts Database and related literature, were summarized under the new taxonomic framework of Gesneriaceae. The results showed that the cytological data in Didymocarpoideae was still insufficient. Chromosome number of less than 25% species in this subfamily were reported, and that for many genera have never been reported. Some newly revised genera show uniform somatic chromosome number. However, some genera, such as Henckelia and Didymocarpus, have great variation in chromosome number. Based on these available cytological data, several comments and suggestions on the evolution of chromosome and its influence to species diversification in this family were proposed. It was speculated that both polyploidy and dysploidy of chromosome possibly play important roles to the diversification of some genera. Future works based on new chromosome painting techniques, convinced phylogenetic evidences, and genomics are warranted in studying chromosome evolution of this group.

Abstract:Postharvest physiology in the world begins approximately in the 1920s mainly for the supply of fresh fruits and vegetables concerning preservation and transportation. With the rapid development and efficient application of genomics, transcriptomes, metabolomes, proteomics and other technical means, postharvest research of fruits and vegetables has developed greatly in the 21^st century. The major progresses include the presence of Met oxidation regulated by Met sulfoxide reductases A and B in relation to down-regulation of LcMsrA1/B1 leading to accelerated oxidation of LcCaM1 and enhanced LcNAC13 expression and DNA binding activity of LcWRKY1 in litchi fruit, a negative effect of MaMYB3 on starch degradation by directly inhibiting the starch degradation-related gene, MabHLH6, to delay the ripening of banana fruit, the identifications of α-and β-branched carotenoid-transformed R2R3-MYB transcription factor of citrus fruit and different members of the TPS family of steroid synthase-encoding genes, WRKY and AP2/ERF transcription factors involved in the aroma formation of peach fruit, and a vacuolar processing enzyme gene, SlVPE3, to regulate the resistance of tomato fruit to pathogens by activating the inhibitor of proteinase (KTI4). According to the SCI publications using postharvest as a key word in the recent years, it is suggested that the postharvest physiology in China is closely related to the development frontier and is generally recognized as the international level, with some problems such as a large discipline but lack of leading publications and scientists or talents. An emphasis on increased financial support, prior basic research, enhanced international cooperation, and improved research team in the discipline development is proposed.

Abstract:In eukaryotic cells, the ATP-dependent chromatin remodeling complexes utilize the energy of ATP to disrupt nucleosome DNA contacts, move nucleosomes along DNA, and remove or exchange nucleosomes. They thus make DNA/chromatin available to proteins that need to access DNA or histones directly during cellular processes. The first chromatin remodeling complex was found in yeast, containing at least 11 subunits by biochemical analysis. However, the chromatin remodeling complexes in plants are less known. The studies on plant chromatin remodeling factors were reviewed, which would provide insights into the involvement of plant chromatin remodeling in development.

Abstract:Streptomyces widely exist in nature with various functions. Their basal hyphae are multi-nucleated with septa, and spore chains are attached to aerial hyphae. The life cycle is completed from spore germination to spore release. Streptomyces are able to colonize the roots, stems, leaves and other parts of plants. They secrete various metabolites which play important roles in plant growth promotion and biological control. The functions of Streptomyces mainly focused on the enhancement of plant nutrient uptake, promotion of plant growth, and increase of the ability of plants coping with biotic and abiotic stresses were reviewed. The future research directions and application were also prospected.

Abstract:Tea (Camellia sinensis) volatile compounds play important roles in both tea aroma quality and tea plant defense against environmental stresses. In addition to volatile terpenes and volatile fatty acid derivates, volatile phenylpropanoids/benzenoids (VPBs) play important, but relatively underappreciated, roles in tea aroma quality and the ecological functions of tea plants. Owing to these contribution, biosynthesis of VPBs in tea have attracted increasing interest. The recent progress in research into some characteristic VPBs directly investigated in tea were summarized, including biosynthesis pathways of 2-phenylethanol, phenylacetaldehyde, and some VPBs, and their formations in response to light stress; biosynthesis pathways of 1-phenylethanol and acetophenone, and their formations in response to insect stress; biosynthesis pathway of indole and its formation in response to temperature and wounding stresses. We also discuss the potential occurrence of some noncanonical biosynthetic pathways for VPBs in tea and the special response mechanism of VBP formations under some stresses.

Abstract:The particular geographical location and climate conditions of Dinghu Mountain National Nature Reserve create a unique ecological system and breed diverse plants and microbials. In order to exploit microbial resources for discovery of bioactive substances, the bioactive secondary metabolites of the fungi and actinomycetes derived from forest soil in Dinghu Mountain National Nature Reserve has been focused. Some recent progresses of this work are summarized.

Abstract:Orchidaceae is the second largest family of flowering plants. There are 28 000 species in 736 genera identified, among them, 343 species in 82 genera are used as medicine, such as Dendrobium officinale, Gastrodia elata, Bletilla striata, Anoectochilus roxburghii, and so on. The main functional constituents in medicinal Orchidaceae plants are polysaccharides, stilbene derivatives, phenolics, terpenoids, alkaloids, flavones and sterols. Water-soluble polysaccharide in orchid plant are mainly composed of mannose and glucose, which is one of important pharmacological active constituents with many pharmacological functions, such as enhancing immunity, anti-tumor, anti-oxidation, lowering blood glucose and improving memory. The structure, pharmacological function and biosynthesis of active polysaccharide in medicinal Orchidaceae plants are reviewed, and some key problems were proposed for further research, which would provide references for further promoting the protection and rational exploitation of medicinal resources of Orchidaceae.