采用无人机量测与卫星遥感影像分析红树林生长分布规律

使用无人机获取研究区域高空间分辨率正射影像,结合近50年卫星遥感影像,通过人工目视解译方法提取并统计历年红树林面积分布大小和区域.结果显示:1)本区域植被以红树林和互花米草为主,分别对2012、2015、2018和2019年红树林与互花米草面积进行解译分析,红树林与其他植被面积平均比例约为1∶6;2)近年研究区域红树林面积波动较大,从1973年至1984年红树林面积维持在13.5 hm^(2),1984年至2001年红树林面积急剧减少至0.19 hm^(2),2001年至2019年红树林面积逐步恢复至2.14 hm^(2);3)互花米草入侵和人为活动的干扰将对红树林生长和繁衍产生不利影响.该研究可为无人机量测和遥感技术在植被保护中的应用提供相关参考.

The Community Structure of Benthic Macroinvertebrates Associated with Spartina alterniflora in the Yangtze Estuary, in China

Benthic macroinvertebrate communities in Spartina alterniflora zones in the Yangtze Estuary, in China, were investigated seasonally in 2005, and their structure and biodiversity were analyzed. Twenty-one species were identified, across four Classes; 10 species of Crustacea, five species of Polychaeta, five species of Gastropoda, and one species of Lamellibranchia. Dominant species included： Assiminea sp., Notomastus latericeus, Cerithidea largillierl, Gtauconome chinensi and Gammaridae sp. Functional groups were comprised of a phytophagous group and a detritivorous group. The average density of all benthic macroinvertebrates was 650.5 ±719.2 inds/m^2 in the survey area. The high value of the standard deviation of the average density was a result of abundant Assiminea sp. at Beihu tidal flats. The average density of macroinvertebrates from Beihu tidal flat, Chongming Dongtan to Jinshanwei tidal flat decreased gradually. There was significant difference between compositions and abundance of macroinvertebrates along the estuary gradient （P 〈 0.05）. The density and biodiversity were highest in summer and lowest in winter. The mean biomass of macroinvertebrates was 20.8 ± 6.1 g/m^2. Biomass changed seasonally in the same way as density, with the change in biomass being： summer （Aug.） 〉autumn （Oct.） 〉spring （Apr.） 〉 winter （Dec.）. A BIO-ENV analysis showed that the mean grain size of sediment, height of Spartina and salinity were the ma- jor factors which affected the structure of the macroinvertebrate community. Variations in the community structure were probably caused by the population dynamics of S. alterniflora along with the variation in sampling time and location.

Exploration and Innovation of Distant Hybridization Germplasm of Oryza sativa and Spartina alterniflora

[Objective] The aim was to explore salt-resistant Spartina alterniflora and high-yield rice with germplasm resource in order to create new salt-resistant rice species with dual-purpose of food and forage. [Method] From 2009 to 2011, re- searches on distant hybridization of Spartina alterniflora and Oryza Sativa have been conducted with method of distant hybridization breeding. On the other hand, break- through and combination techniques （four selected one） were adopted to find the new rice species, including techniques of planting and selection in seashore, cyto- logical detection and selection, phenotype selection of backcross, and molecular marker assisted selection. [Result] Success rate of distant hybridization from 2009 to 2010 was 1.39%. RAPD molecular identification of 7C14 and rice female parent of Zhongxiang No.l, seed 2 was carried on with distant hybridization of male parent of Spartina altemiflora （H）. The results showed that bands same with Spartina alterni- flora parents were found in RH-1-10K205-7C14xH, RH-2-8K157-7C14xH, and RH-13- 9H5-Zhongxaing No.1 xH. Considering absent situation in rice parents, distant hy- bridization strains above were found with same parental genetic element as Spartina alterniflora. Female parent of rice 7K339, however, was under RAPD molecular identification with male parent of Spartina alterniflora. The result showed that bands same with Spartina alterniflora parents were found in RH-5-10K215, RH-6-8K48, RH- 12-9H9, RH-14-9H8 and RH-16-9H28. Considering absent situation in rice parents, distant hybridization strains above were found with same parental genetic element as Spartina altemiflora. Rest hybrid strains were found variance with Spartina alterniflora parents and rice parents in varying degrees. [Conclusion] New and excellent rice species of dual-purpose solves problem not only about salt-resistant species badly needed in coastal development and treatment of saline and alkaline land, but about fine fodder and roughage for herbivore, as well. What＇s more, this is of scientific significance in recourse utilization, efficiency improvement in agriculture, food security, and cultivation strategy.

A Study of Fructification Quantitative Characteristics of Spartina alterniflora Lossel in Mangroves

[Objective] The countermeasure on the number of fructification of Spartina alterniflora in the period of sexual reproduction and the component of seed yielding construction was explored.[Method] The Spartina altemiflora in Mangroves conservation zone located at Hepu of Guangxi being taken as experimental material, its morphological and quantitative characteristics, as well as the weight of 100 full seeds at maturity stage in three different growth conditions（ clay, loam and sand） were studied. [ Results] The results showed that Spartina alterniflora had the best growth pattern in the loam. The morphological factors of fructification of S. altemiflora grown in sand were larger then in others. In the three growth conditions the order of quantitative characteristics of fructification of S. alterniflora was clay 〉 sand 〉 loam and the seeds in spikelet at top position were more maturity than those at the button position. [ Conclusion] In good condition, the Spartina altemiflora growth was vigor but the ratio of seed-setting was low.

Analysis on Genetic Structure of Spartina alterniflora Populations in China Based on EH277045-derived Sequence

[Objective] This study aimed to analyze the genetic structure of eight populations of Spartina alterniflora in China at the nuclear DNA level.[Method] The EH277045-derived sequences were amplified from 75 samples in 8 populations and directly sequenced.Nucleotide diversity,haplotype diversity,the mean value of Nei＇s genetic distance,genetic differentiation index FST and other genetic parameters were calculated to estimate the genetic diversity and genetic differentiation of S.alterniflora populations in China.[Result] 75 samples were divided into 25 haplotypes by 28 polymorphic sites.Relatively high nucleotide diversity（π=0.011） and haplotype diversity（Hd=0.794） were detected.The mean value of Nei＇s genetic distance and genetic differentiation index FST among eight populations were 0.056 and 0.222,respectively,the Nei＇s genetic distance ranged from 0.000 to 0.189 and FST ranged from 0.000 to 0.444 between each pair of the eight populations.AMOVA result revealed that 79% and 21% of the total genetic variation was partitioned within and among S.alterniflora populations,respectively.[Conclusion] At the nuclear DNA level,there were a relatively high level of genetic diversity and a relatively low level of genetic differentiation among S.alterniflora populations in China,and the genetic diversity existed mainly within rather than among populations.

湿地植物去除重金属的研究进展

总结了湿地沉积物特性、共生体(细菌、真菌和附生植物)、植物改变金属形态、叶片上金属的释放等4个方面影响湿地植物去除重金属的因素。

Maize (Zea mays L.) and Cotton (Gossypium hirsutum L.) Straw Decomposition in Soil: Effect of Straw Placement, Mineral Nitrogen and Tillage

With the present understanding that decomposing straw may not onlyaffect soil properties, but pos- sibly greenhouse gas emissions aswell, focus among environmental researchers has gradually expanded toinclude understanding of decomposition rate and stability of straw ofdifferent plants in different soils under different managementconditions. Against such a background, a short-term (60 days)greenhouse simulation experiment was carried out to study the effectsof straw placement, external mineral N source and tillage on strawdecomposition of maize and cotton in two contrasting soils, a redsoil (Ferrasol) and a black soil (Acrisol).

Responses of CH_4 Emissions to Nitrogen Addition and Spartina alterniflora Invasion in Minjiang River Estuary, Southeast of China

The nitrogen （N） input and Spartina alterniflora invasion in the tidal marsh of the southeast of China are increasingly serious. To evaluate CH4 emissions in the tidal marsh as affected by the N inputs and S. alterniflora invasion, we measured CH4 emissions from plots with vegetated S. alterniflora and native Cyperus malaccensis, and fertilized with exogenous N at the rate of 0 （NO）, 21 （N1） and 42 （N2） g N/（m2.yr）, respectively, in the Shanyutan marsh in the Minjiang River estuary, the southeast of China. The average CH4 fluxes during the experiment in the C. malaccensis and S. alterniflora plots without N addition were 3.67 mg CHa/（m2.h） and 7.79 mg CH4/（m2-h）, respectively, suggesting that the invasion of S. alterniflora into the Minjiang River estuary stimulated CH4 emission. Exogenous N had positive effects on CH4 fluxes both in native and in invaded tidal marsh. The mean CH4 fluxes of NI and N2 treat- ments increased by 31.05% and 123.50% in the C. malaccensis marsh, and 63.88% and 7.55% in the S. alterniflora marsh, respectively, compared to that of NO treatment. The CH4 fluxes in the two marshes were positively correlated with temperature and pH, and nega- tively correlated with electrical conductivity and redox potential （Eh） at different N addition treatments. While the relationships between CH4 fluxes and environmental variables （especially soil temperature, pH and Eh at different depths） tended to decrease with N additions. Significant temporal variability in CH4 fluxes were observed as the N was gradually added to the native and invaded marshes. In order to better assess the global climatic role of tidal marshes as affected by N addition, much more attention should be paid to the short-term temporal variability in CH4 emission.

An Innovative Strategy for Reciprocal Distant Hybridization between Spartina alterniflora and Rice

[Objective] This study aimed to explore germplasm resources of salt toler- ant Spartina alterniflora and high yield rice, and develop an innovative strategy for distant hybridization between S. altemiflora and rice. [Method] Crossing （rice ♀ ）： hot water emasculation and glume-cutting pollination method, heat emasculation and pollen-suction pollination method; reciprocal crossing （S. alterniflora ♀ glume-cutting emasculation and pollination method, continuous emasculation-pollination method, hot water emasculation and continuous emasculation-pollination method. [Result] In crossing groups （rice ♀ × S. alterniflora ♂ ）, compared with hot water emasculation and glume-cutting pollination treatment, the number of seed-bearing combinations, seed number per spike and seedling emergence rate in heat emasculation and pollen-suction pollination treatment were improved by 34.09%, 121.21% and 60.07%, respectively; hybridization efficiency was improved by 6-7 times. In reciprocal cross- ing groups （S. altemiflora ♀× rice ♂ ）, compared with glume-cutting emasculation and pollination treatment, the number of seed-bearing combinations and seed num- ber per spike in continuous emasculation-pollination treatment were improved by 3.14 and 4.21 times, respectively; seedling emergence rate was improved by 68.47%; hybridization efficiency was improved by 7-8 times. [Conclusion] Heat emas- culation and pollen-suction pollination method is suitable for hybridization between rice ♀× S. alterniflora ♂; continuous emasculation-pollination method is suitable for hybridization between S. alterniflora ♀× rice ♂.

Study on the removal of oil pollution from terrestrial sources in Beitang estuary wetland of Spartina alterniflora

With the rapid development of the petroleum industry and oil spill occurredfrequently in recent years, marine oil pollution is serious. Oil pollution from terrestrialsources is an important source of marine oil pollution. In China, oil pollution fromterrestrial sources accounted for more than 80% of the total marine pollutants. Wetlandhas great ecological and environmental value, and researches found that wetland hasthe function of purifying oil pollutants. Beitang Estuary in Tianjin Binhai New Area is amajor fishery port, and also the main sewage outfall. In recent years, with the increaseof oil pollution from terrestrial sources, water quality in Beitang River is deteriorating.The Beitang Estuary has a large area of natural Spartina alterniflora wetland, whichmay effectively remove oil pollution. Environmental investigation was carried out on thewharf, channel and coastal zone near Beitang Estuary. The results showed that theeutrophication in Beitang Estuary is serious, and the water quality is inferior to theworse than the fourth class of sea water quality. Inorganic nitrogen, active phosphateand petroleum hydrocarbons are the main pollutants. Reed, Spartina alterniflora andSeepweed were the dominant species in the Beitang Estuary, and petroleumhydrocarbons were detected in the three plants. It showed that the Beitang Estuary waspolluted by petroleum hydrocarbons, and the three kinds of plants have the ability toabsorb petroleum hydrocarbons. Survey results showed that, whether in the surfaceseawater or sediment, the oil content near the wharf was higher than the channel; thepetroleum hydrocarbon content in the channel was higher than the coastal zone. Theroots, stems and leaves of Spartina alterniflora can intercept oil pollution from terrestrialsources. In addition to absorbing petroleum hydrocarbons, Spartina alterniflora alsoprovides a good habitat for microorganisms,to accelerate microbial degradation ofpetroleum hydrocarbon. Spartina alterniflora wetland has the obvious effect forreducing terrigenous oil pollutants.

Changing the Moisture Content of the Spartina and Miscanthus and Willow Shoots during Storage in Natural Conditions

The aim of this study was to determine the characteristics of the distribution of energy plant moisture content along the height of their shoots and the dynamics of moisture during storage in natural conditions. The shoots of Spartina, Miscanthus and willow were used in the study. Entire shoots were cut into sections of 10 cm and for each set in monthly cycles for six months moisture content was evaluated. After a month＇s storage of freshly cut shoots the biggest decrease of content moisture in the shoots of Spartina and Miscanthus was recorded, by 31% and 22%, respectively, and the lowest in willow shoots （12%）. After sixth months of shoots storage the lowest moisture content （10%-12%） was reached in miscanthus. The most uneven moisture content along the height of shoots Spartina was characterized because on one third of the height from the bottom, the moisture content of shoots was 20%, and the top had moisture content in the range 5%-10%. Willow shoots were characterized by the smallest drop in moisture, and the final moisture content was about 23%, with the top part of moisture content of 10%-20%. The dynamics of moisture change during the six months of storage of grass shoots （Miscanthus and Spartina） in natural conditions under roofing was described by one power function regression, and willow by another one. Empirical models can be used to predict changes in moisture content of these plants in experiment conditions, since the coefficients of determination were 94.66% and 89.18%, respectively.

互花米草刨花板的工艺研究

研究了以互花米草为原料的刨花板制造工艺,互花米草通过截断、再碎、干燥等加工制成工艺刨花碎料,以脲醛树酯为胶黏剂,采用正交实验设计,研究施胶量、热压温度、目标密度等工艺因素对刨花板主要物理力学性能(静曲强度、弹性模量、内结合强度、吸水厚度膨胀率)的影响,确定最佳热压工艺条件。研究表明:(1)互花米草可以用于刨花板制造;(2)脲醛树酯胶黏剂可以用于互花米草刨花板制造;(3)最佳工艺参数:施胶量12%、热压温度170℃、目标密度0.85。

稻米香飘东海滩

1500名建设者开进东滩,犹如"红军过草地"。国际性难题被一位中国农民攻克。最终,5万亩东滩将被建成一个集水稻种植、大米加工、观光旅游、休闲度假、科技研发、科普教育等为一体的综合性现代化农业园区,成为上海的一座生态粮仓。

Environment-ecosystem dynamic processes of Spartina alterniflora salt-marshes along the eastern China coastlines

Spartina alterniflora is ecologically important in its original habitat; however, it has caused controversy since it was introduction into China(now it has been spreading rapidly on the Jiangsu, Shanghai, Zhejiang and Fujian coasts). The purpose of the present contribution is, on the basis of an analysis and synthesis of existing data sets, to evaluate the environmental-ecological effects of S. alterniflora, and to identify the relevant scientific problems that require further research in the future. Investigations have shown that, by reducing the near-bed shear stress associated with tidal currents, S. alterniflora can enhance the settling flux of suspended sediment and deposition rate on the tidal flats over the region. Further, field survey and analysis indicate that the S. alterniflora salt-marsh has a high primary production and provides a new type of habitat for the native benthic fauna. Some macro-, meio- and micro-fauna that used to live in the native salt-marshes have adapted to the S. alterniflora salt-marsh, forming a new ecosystem. Under the influences of a number of background factors, such as latitude variations and the coastal type, the environmental-ecological changes induced by Spartine have regional differentiations. To the north of Hangzhou Bay, with a high position of the pre-Holocene stratum base, a large width of the tidal flats, and a gentle bed slope, only a small part of the intertidal zone is occupied by the S. alterniflora salt-marsh. Here, the S. alterniflora salt-marshes mainly play a positive role in coastal protection and ecosystem functioning. In contrary, to the South of Hangzhou Bay, The pre-Holocene deposits are situated in relatively deeo waters, and the width of the tidal flats formed within coastal embayments is relatively narrow. As such, the expansion of S. alterniflora has squeezed the living space of other intertidal organisms, thus has a negative ecological effect. Therefore, the regional differentiation of the Spartina effects should be sufficiently considered in coastal development and management. Furthermore, in order to predict the future evolution of the S. alterniflora wetlands over the region, in addition to in situ monitoring and measurements, an ecosystem dynamic model should be established, taking into account the coupling of the rerrestrial and marine environmental-ecological processes.

Changes in Soil Organic Carbon Dynamics in a Native C4 Plant-Dominated Tidal Marsh Following Spartina alterniflora Invasion

Invasion of an exotic C4 plant Spartina alterniflora has been shown to increase soil organic carbon （SOC） concentrations in native C3 plant-dominated coastal wetlands of China. However, little is known about the effects of S. alterniflora invasion on SOC concentrations and fractions in tidal marshes dominated by native C4 plants. In this study, a field experiment was conducted in a tidal marsh dominated by the native C4 plant Cyperus malaccensis in the Minjiang River estuary, China. Concentrations of SOC and liable SOC fractions, dissolved organic carbon （DOG）, microbial biomass carbon （MBC）, and easily oxidizable carbon （EOC）, were measured in the top 50-cm soils of the C. malaccensis community, as well as those of three S. alterniflova communities with an invasion duration of 0-4 years （SA-4）, 4-8 years （SA-8）, and 8-12 years （SA-12）, respectively. Results showed that both SOC stocks in the 50-cm soils and mean SOC concentrations in the surface soils （0-10 cm） of the C. malaccensis community increased with the duration of S. alterniflora invasion, whereas SOC concentrations in the 10-50-cm soils decreased slightly during the initial period of S. alterniflora invasion, before increasing again. The pattern of changes in labile SOC fractions （DOC, MBC, and EOC） with invasion duration was generally similar to that of SOC, while the ratios of labile SOC fractions to total SOC （DOC：SOC, MBC：SOC, and EOC：SOC） decreased significantly with the duration of S. alterniflora invasion. The findings of this study suggest that invasion of the exotic C4 plant S. alternifora into a marsh dominated by the native C4 plant C. malaecensis would enhance SOC sequestration owing to the greater amount of biomass and lower proportion of labile SOC fractions present in the S. alterniflora communities.

Spatial Variation of Soil Inorganic Carbon Reserves of Typical Estuarine Wetlands in Jiaozhou Bay, China

The storage of inorganic carbon in estuarine wetlands is of great significance for mitigating global warming. The Dagu River estuary and Yanghe River estuary of Jiaozhou Bay were selected as sampling areas, and data analysis was carried out by Duncan method to explore the distribution characteristics and influencing factors of soil inorganic carbon(SIC) reserves. The results showed that increasing distance from the estuary led to higher reserves in the mudflat along the coastal zone. The scouring action of seawater bodies was the main factor driving this distribution. In the vertical section, the SIC reserves in 40–60 cm depth were relatively high, accounting for 34.11% of the 0–60 cm soil depth, and resulting from the transport of water and salt in seawater. In the river flat along the vertical coastal zone, the SIC reserves first decreased and then increased with increasing distance from the sea, and the SIC reserves in 0–20 cm depth were relatively high in the vertical section, accounting for 38.18% of the 0–60 cm soil depth. These reserves were affected by synergetic factors such as oceanic factors and anthropogenic activities. The invasion of Spartina alterniflora decreased the SIC reserves of wetlands, mainly due to its root transformation and the differences of growth characteristics and years being the main reasons for the observed decreases. Aquaculture activities changed the physical and chemical properties of the soil in aquaculture ponds, and consequently changed the distribution of SIC reserves.