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Established in 1955, and after three generations of persistent effort to overcome many challenges, Saihanba Forest Farm, Hebei Province in northern China has been transformed from an unproductive patchwork of inferior secondary forests, degraded grasslands and invading desert to an extensively planted and productive forest covering over 730 km2. This represents a magnificent achievement in ecological rehabilitation, and constitutes both an excellent model and a worthy preced [Detail] ...
This paper explains and discusses the concepts of ecological conservation and construction in China in three parts. The first part provides a brief description of the historical background of ecological activities in China and their major achievements in the past. The second part is a comprehensive review of various types of ecological control activity aimed at the improvement of natural and artificially established ecosystems at the landscape, regional (watershed) and higher levels. The scope of and differences between some ecological terms used in China such as ecological protection, conservation, remediation (rehabilitation), restoration as well as the reestablishment of new ecosystems are elaborated. The review suggests that the term “ecological conservation and construction” should be used to embrace all types of ecological control activity in China. Finally, five guidelines are proposed for promoting the implementation of ecological conservation and construction in China based on the two important governmental documents related to the development of ecological civilization in China.
Eucalypt plantations in China currently exceed 4.5 Mhm2, and this country has the third largest area of such plantations after India and Brazil. China’s eucalypt industry now comprises a complex, multifaceted industry including seedling propagation, fertilizer production and supply, plantation silviculture, harvesting and transport, wood processing for products including lumber, pulp and paper, and wood-based panels, as well as bioenergy production and various forest byproducts and non-wood forest products. In 2015, the combined value of output of this whole industry was around 300 billion CNY. Chinese research and development (R&D) has been instrumental in supporting growth and development across the whole breadth of the country’s eucalypt industry. In this report, recent advances in this R&D are reviewed under six key topics: (1) advanced propagation technology; (2) genetic resources and breeding; (3) targeted silviculture; (4) eucalypt disease and pest management; (5) enhancing plantation ecology and sustainability; and (6) wood processing and byproduct technology. R&D has greatly facilitated expansion and proliferation of all parts of China’s eucalypt industry. This industry is now of major importance to China’s economy; it involves tens of thousands of growers and companies that provide livelihoods for hundreds of thousands of people.
Betula platyphylla Suk. is one of the most widely distributed species of Betula, the fourth most valuable timber species in north-eastern China and also a common tree species for landscaping. Over the past 30 years, effective progress has been made in genetic improvement and molecular breeding of B. platyphylla. There has been extensive research on breeding techniques, including the collection and conservation of B. platyphylla germplasm resources, provenance trials, intensive breeding techniques, crossbreeding and asexual propagation techniques, ploidy breeding and mutation breeding technology, genome sequencing, gene cloning, transgenic and molecular mechanisms of wood formation. A Betula germplasm resource collection has been established by collecting different provenances, and full-sib and half-sib families. In addition, the geographic variation patterns of B. platyphylla provenances have been revealed, and the provenance division and superior provenance selections made. B. platyphylla flowering and seeding have been improved through intensive breeding techniques. Interspecific hybridization, intraspecific hybridization and parallel crosses were made using fine parents, and B. platyphylla intensive seed orchards have been established. Systems of asexual propagation, including cuttings, grafting and tissue culture have been established. A B. platyphylla tetraploid was successfully constructed and a B. platyphylla triploid seed orchard established. The growth, wood property and resistance genes of B. platyphylla have been cloned. An efficient B. platyphylla transgenic system mediated by Agrobacterium tumefaciens was established, and genes encoding B. platyphylla insect resistance, drought resistance and salt tolerance, lignin synthesis, flowering, hormone transport and balance obtained. B. platyphylla molecular markers were developed and the high density B. platyphylla genetic map constructed. All this research has provided a model and data for the foundation of forest genetic improvement and applied research.
Desertification has been caused by various factors and is a major environmental problem and development bottleneck faced by the world. It is also a serious threat to ecological security and to sustainable economic and social development. As a stubborn world problem, focused on by the United Nations 2030 sustainable development goal 15.3, China aims to combat desertification by implementing the “eight-column four-beam” strategy, and also suggest the “four-medicine” approach for global desertification governance. This includes the development of the United Nations Convention to Combat Desertification protocol, unified global compliance and compliance metrics; building a global observation network, and monitoring land changes based on remote sense; preparing the global natural desert (heritage) list, leaving the original deserts for future generations; initiating the global action of combating desertification, and striving to achieve a land degradation-neutral world by 2030.
The Chinese Government is committed to forest certification as a market-based instrument to promote sustainable forest management. Forest certification includes a number of regulations, rules and policy paradigms related to certification and there are numerous challenges facing the uptake of forest certification in China. In particular, the ban on commercial logging in natural forests implemented by the Natural Forest Protection Program has resulted in little demand for forest certification of natural forest management units. However, there are also certification opportunities, such as the certification of non-timber forest products that benefit local communities who depend on forests for the goods and services they provide. This paper provides an overview of progress in forest certification in China, including its development history, organizational structure, scheme documents, certification scopes and standards, accreditation, certification bodies and auditors, and certification logos. The paper also focuses on government support for the supervision and management of forest certification through policy incentives, including the potential government procurement and subsidy policies for certified forest products. Finally, the paper analyzes certified non-timber forest products as an example of the value of certification to promote sustainable forest management and how the concept of forest certification can be used to add value to forests and ensure they are responsibly and sustainably managed. In general, forest certification in China has a clear role in sustainable forest management, both for timber and non-timber forest products.
A large number of expressed sequences tags are available for Citrus spp., which provides an opportunity to understand genomic organization of the transcribed regions. Here, we report a detailed analysis of repetitive elements including tandem repeats (TRs) and transposable elements (TEs) in the transcribed region of the Citrus spp. On average, 22% of the expressed sequence tags (ESTs) contain TRs. The relative density of TR classes is highly taxon-specific. For instance, Citrus limonia has a high relative density of mononucleotide repeats, whereas dinucleotide repeats are rare. The proportions of 2–6, 7–30 and 31–50 bp repeats were almost identical in all studied species except for C. limonia and C. limettioides. We found that<1% of the citrus ESTs have a similarity with transposable elements. Transcriptional activity of transposable element families varied even within the same class of elements. A high proportion of transcriptional activity was observed for gypsy-like TEs compare to other TE classes. While TEs are relatively rare, TRs are abundant elements in ESTs of citrus. The high proportion of TRs that have a unit size longer than 6 bp raises the question about a possible functional or evolutionary role of these elements.
The genus Quambalaria includes several important pathogens of species of Eucalyptus and Corymbia, mainly causing leaf and shoot blight. Recently, extensive shoot and leaf dieback and stem cankers suspected to be Quambalaria diseases have been found on young Eucalyptus urophylla × E. grandis trees in Guangdong and Hainan Provinces. The occurrence of Quambalaria species and their association with eucalypt hosts within China needs to be investigated for tree diseases management. The isolates from the diseased samples were identified based on their morphological structures and phylogenetic analyses with DNA sequence data for the internal transcribed spacer region and large ribosome subunit RNA of the nuclear rDNA. This work revealed that three species of Quambalaria were present: Quambalaria pitereka from Corymbia citriodora, Q. eucalypti from E. urophylla × E. grandis, both isolated from young eucalypt leaves and shoots in Guangdong Province, and Quambalaria simpsonii, which was isolated from stem cankers of E. urophylla × E. grandis at four different sites across Guangdong and Hainan Provinces. These results confirmed that Quambalaria agents were associated with the diseases occurring on eucalypt hosts in South China. This is the first report of Q. eucalypti in Asia and the first report of Q. simpsonii in China on Eucalyptus trees.
While low-to-moderate resolution gridded climate data are suitable for climate-impact modeling at global and ecosystems levels, spatial analyses conducted at local scales require climate data with increased spatial accuracy. This is particularly true for research focused on the evaluation of adaptive forest management strategies. In this study, we developed an application, ClimateAP, to generate scale-free (i.e., specific to point locations) climate data for historical (1901–2015) and future (2011–2100) years and periods. ClimateAP uses the best available interpolated climate data for the reference period 1961–1990 as baseline data. It downscales the baseline data from a moderate spatial resolution to scale-free point data through dynamic local elevation adjustments. It also integrates and downscales the historical and future climate data using a delta approach. In the case of future climate data, two greenhouse gas representative concentration pathways (RCP 4.5 and 8.5) and 15 general circulation models are included to allow for the assessment of alternative climate scenarios. In addition, ClimateAP generates a large number of biologically relevant climate variables derived from primary monthly variables. The effectiveness of the local downscaling was determined based on the strength of the local linear regression for the estimate of lapse rate. The accuracy of the ClimateAP output was evaluated through comparisons of ClimateAP output against observations from 1805 weather stations in the Asia Pacific region. The local linear regression explained 70%–80% and 0%–50% of the total variation in monthly temperatures and precipitation, respectively, in most cases. ClimateAP reduced prediction error by up to 27% and 60% for monthly temperature and precipitation, respectively, relative to the original baselines data. The improvements for baseline portions of historical and future were more substantial. Applications and limitations of the software are discussed.
Papilio paris butterfly wings were replicated by a sol-gel method and a calcination process, which could take advantage of the spatial features of the wing to enhance their photocatalytic properties. Hierarchical structures of P. paris-carbon-TiO2 (PP-C-TiO2) were confirmed by SEM observations. By applying the Brunauer-Emmett-Teller method, it was concluded that in the presence of wings the product shows higher surface area with respect to the pure TiO2 made in the absence of the wings. The higher specific surface area is also beneficial for the improvement of photocatalytic property. Furthermore, the conduction and valence bands of the PP-C-TiO2 are more negative than the corresponding bands of pure TiO2, allowing the electrons to migrate from the valence band to the conduction band upon absorbing visible light. That is, the presence of C originating from wings in the PP-C-TiO2 could extend the photoresponsiveness to visible light. This strategy provides a simple method to fabricate a high-performance photocatalyst, which enables the simultaneous control of the morphology and carbon element doping.
Ginkgolic acids are unwanted constituents in standard Ginkgo biloba leaves extracts. Thus, for the quality control of ginkgo extracts, it is important to establish an effective degradation method, with high catalytic efficiency and safety, to remove ginkgolic acids. Laccases are oxidases with potential for application in elimination of hazardous phenolic compounds. In this study, single-factor and orthogonal experiments were used to optimize extraction of ginkgolic acid from G. biloba sarcotestae. The results showed that ethanol was the best solvent, with the highest extraction rate for ginkgolic acid at 85% ethanol. On this basis, we measured ethanol volume fraction, extraction time, temperature and solid-liquid ratio using an orthogonal experiment. By using absorbance of 310 nm as standard, the optimal extraction conditions were 85% ethanol with, solid-liquid ratio of 1:14 at 40°C for 12 h. These conditions gave a ginkgolic acid yield of 73.1 mg·g−1. Subsequently, recombinant laccase was used to degrade the ginkgolic acid in several laccase/mediator systems, of which LacC was the best. At 50°C, pH 4.5, enzyme concentration of 0.01 U·mL−1, 0.5 mmol·L−1 mediator ABTS and reaction time of 3 h, the degradation rate of ginkgolic acid reached 100%. These results lay the foundation for research on and application of biological enzymes for detoxification of G. biloba extracts.
Potential competition for biomass for current and future bioenergy/biofuel uses in Brazil, Denmark, Sweden and the USA were compared. In each of these countries, bioenergy and biofuels are already important in their energy mix. However, there is limited competition for biomass between bioenergy (heat/power/residential/industrial) and transportation biofuel applications. This situation is likely to continue until advanced biofuel technology becomes much more commercially established. In each of these countries, biomass is predominantly used to produce bioenergy, even in those regions where biofuels are significant component of their transportation sector (Brazil, Sweden and USA). The vast majority of biofuel production continues to be based on sugar, starch and oil rich feedstocks, while bioenergyis produced almost exclusively from forest biomass with agricultural biomass having a small, but increasing, secondary role. Current and proposed commercial scale biomass-to-ethanol facilities almost exclusively use agriculture derived residues (corn stover/wheat straw/sugarcane bagasse). Competition for biomass feedstocks for bioenergy/biofuel applications, is most likely to occur for agricultural biomass with coproduct lignin and other residues used to concomitantly produce heat and electricity on site at biofuel production facilities.
Wood properties are important traits that determine quality of structural wood. With the aim of performing efficient early selection for wood properties, we investigated genetic variation in 20 Larix kaempferi clones aged from 4 to 15 years for four quality traits: wood density, wall thickness to lumen area, microfibrillar angle (MFA) and modulus of elasticity (MOE). We observed that age-related trends in overall means varied for different traits: MFA decreased with the age, while the others generally increased with the age. Phenotypic variance always showed significant differences from the age of 8 years onward, with CVG ranging from 4% to 25%. Also, clonal repeatability increased steadily until 9 years old and then kept medium or higher intensity (0.4–0.8). After the age of 6, genetic correlations were generally higher than phenotypic correlations. Estimates of early selection efficiency suggested that the optimal selection age for wood density was at age 5–6 years, while it was 9–10 years for the other traits. In combination with previous results, we proposed a comprehensive early selection strategy for larch clonal breeding that involved selection based on nursery rooting ability, phenology, growth traits, and wood properties.