Spartina Townsendii an der Westküste von Schleswig-Holstein

Ohne ZusammenfassungMit 11 Textabbildungen.     

刈割加遮荫综合治理互花米草(Spartina alterniflora)

互花米草(Spartina alterniflora)是我国危害最严重的外来入侵植物之一,探索经济有效的控制治理技术对保护我国海滩生态环境具有重要意义。本研究集成了刈割与遮荫2种物理控制方法综合治理互花米草,并与单一刈割的治理效果进行对比。结果表明:单一刈割虽然显著降低了互花米草植株的节数、株高和地上生物量等个体生长特征(P0.05),但对互花米草植株的节长、基茎、种群密度、结穗率和穗长等特征没有显著影响(P0.05),6个月后互花米草刈割种群的无性生长和有性生殖特征与对照种群已无显著差别。而刈割加遮荫综合处理不仅显著抑制了互花米草节数、节长、基茎、株高、生物量等生长指标(P0.05),而且有效抑制了幼苗形成,完全抑制互花米草的有性繁殖,显著降低种群密度(P0.05),最后导致植株地上部分全部死亡,其控制效果远优于单一刈割处理。刈割与遮荫综合控制的方法主要适用于去除入侵早期、小面积分布的单一互花米草种群并恢复为沙滩,也可以作为生物替代方法的前期处理。     

大米草(Spartina anglica Hubbard)盐腺的形态结构

大米草的盐腺在植物体的分布,除根、根茎、茎、叶鞘的近轴面以及内稃没有外,其他所有气生部分皆具有,尤其以叶片最多。盐腺由两个细胞组成,大的基细胞和小的圆顶状的帽细胞。帽细胞位于基细胞颈状突起上面。两者都具有浓稠的细胞质、大的细胞核多数线粒体以及少数其他细胞器。基细胞具有遍布整个细胞的壁突起和折叠的隔膜系统,将细胞质分隔。帽细胞的显著特征是核仁明显,染色质遍及整个核质并沿核膜分布。基细胞肩部和底部与表皮细胞和叶肉细胞之间没有角质层隔开,而基细胞与表皮细胞和帽细胞邻接的壁上有明显的胞间联丝。大米草盐腺的发育可能与唐氏米草(S.townsendii)相同;其泌盐途径可能是叶米草(S.foliosa)与唐氏米草两者兼有之。     

大米草(Spartina anglica Hubbard)生态型分化的研究

引言我国引进的大米草,来自英国的 Lanca-shire(53°45′N,2°40′W)、Essex(51°48′N,0°40′E)和 Poole Harbour(50°43′N,1°59′W)。这三个地区在地理气候上差异不十分显著,大米草的造种历史近100年,但在这期间是否种群发生种内分化,形成不同生态型?这不仅是种内生态学的理论问题,也对大米草的推广具重要意义。Bryce(1928)已发现 Poole Harbour 和Maningtree 的种群形态不同,前者具长根茎,后者的吸收根接近地面;Van Schreven(1958)     

L'acide diméthylsulfonium-3 propanoïque de Spartina anglica

3-Dimethylsulphoniumpropanoic acid was isolated from Spartina anglica leaves; its structure was determined by spectroscopic methods and confirmed by comparison with a synthetic sample. It is suggested that this compound may have a role in salt resistance.     

互花米草(Spartina alterniflora)潜在分布格局的空间尺度效应

了解不同空间尺度下外来入侵植物互花米草(Spartina alterniflora)的潜在分布格局,有助于制定科学的防治管理策略,维护滨海湿地的生物多样性。研究基于有效的地理分布点位和环境变量数据集,设置了3个研究区幅度(区域、国家、全球)和5种环境变量粒度(30″、1.0′、2.5′、5.0′、10′),应用最大熵(MaxEnt)模型预测互花米草在不同幅度和粒度下的潜在分布,探究互花米草分布格局及其环境影响因子对空间尺度响应。结果表明：(1)MaxEnt模型在不同空间尺度下的预测效果较好,各尺度下测试集的受试者曲线下面积(AUC)值均大于0.8,真实技巧统计值(TSS)值则超过0.56,但模型的预测精度对空间尺度变化较为敏感;(2)不同空间尺度下互花米草的潜在分布格局存在着显著的差异性,表现为适生区面积会随着空间范围扩大或环境变量分辨率降低而提高,且质心位置也在不断发生地带性转移;(3)空间尺度的变化会削弱主要环境变量的解释力。在大尺度范围和低分辨率环境变量图层中,气候因子的重要性较大,而在相反尺度下地形因子的影响度得到提升;(4)研究区范围与环境变量分辨率不匹配时,模型预测精度和物...     

刈割与水位调节集成技术控制互花米草(Spartina alterniflora)

治理和控制外来物种互花米草（Spartina alterniflora）对维护崇明东滩自然保护区生物多样性具有重要的意义和必要性。研究在上海崇明东滩鸟类国家级自然保护区建立的受损滩涂湿地生态修复示范样地中开展“刈割与水位调节集成技术”治理互花米草的物理控制实验,以期寻求有效治理互花米草的控制技术。示范研究结果表明,单一的水位调节方法虽然可以降低互花米草群落的密度和叶面积指数（LAI）,但至水淹处理100d后,处理样区内互花米草的生长和生物量已与对照区无显著差异。单一的水位调节方法不能达到有效快速控制互花米草的效果。通过在互花米草生长关键期（7月的扬花期）刈割＋水位调节集成技术处理后,互花米草地上部分无再新生现象,至当年10月份（生长季末期）,样区内互花米草的地上部分和地下部分已完全死亡并开始腐烂,达到了有效控制互花米草的效果。因此,应用刈割＋水位调节集成技术治理互花米草,必须选择关键季节刈割互花米草地上部分,同时配合一定水位的持续淹水（约3个月）,才能有效发挥其迅速有效治理互花米草的效果。扬花期刈割＋水位调节集成技术可为沿海地区大范围防治互花米草扩散提供有效途径。     

How will warming affect the salt marsh foundation species Spartina patens and its ecological role?

Foundation species structure environments and create refuge from environmental stress. In New England high salt marsh, the grass Spartina patens is a foundation species that reduces salinity, anoxia, desiccation, and thermal stresses through canopy shading and root proliferation. In a factorial S. patens-removal and warming field experiment, foundation species removal strongly impacted every aspect of the community, reiterating the important role of the foundation species S. patens in the high marsh. Given this central role, we hypothesized that facilitation by the foundation species would be even more important under warmer conditions by ameliorating more severe thermal stress. However, the ecological role of S. patens was unaffected by experimental warming, and, independent of the presence of the foundation species, warming had only weak effects on the salt marsh ecological community. Only the foundation species itself responded strongly to warming, by significantly increasing aboveground production in warmed plots. Apparently, amelioration of thermal stress is not as important for salt marsh ecosystem function as S. patens’ moderation of salinity and desiccation stresses. From these experimental results, we anticipate that climate change-associated thermal stress will not greatly affect S. patens-dominated high marsh communities. In contrast, foundation species loss, an emergent conservation issue in Atlantic salt marshes, represents a critical threat to salt marsh ecosystem function.     

互花米草(Spartina alterniflora)草场土壤微生物生态分布及某些酶活性的研究

种植互花米草的盐沼土中,细菌、放线菌和真菌的数量比对照盐沼土中多。就不同深度来说,15—30厘米土层中,细菌数最多。细菌总数的增减趋势是:夏秋两季最多,冬春两季较少。在各生理类群中,氨化细菌占优势;固氮细菌、硝化细菌次之;反硝化细菌和硫酸盆还原细菌最少。内源呼吸作用强度、添加葡萄糖后的呼吸作用强度、氧化丙酮酸的能力和氧化多酚化合物的能力皆显示出同样的趋势,即三年生草场土壤中生物活性最强,光滩土壤中生物活性最弱。在光滩土壤中,脲酶和过氧化氢酶活性很低,而种植互花米草的土壤中这两种酶活性较强,但与种植年限和季节变化无显著相关性。     

江苏沿海互花米草(Spartina alterniflora Loisel)盐沼扩展过程的遥感分析

互花米草(SpartinaalternifloraLoisel)自1982年在江苏沿海栽种以来,在江苏沿海已形成了大片互花米草盐沼。本文通过对历年TM卫星相片上互花米草盐沼的识别、判读及统计,认为江苏沿海互花米草盐沼的年扩展速度在早期较慢,仅为23 4%,中期较快为89%,后期又减慢为48%。结合野外调查,绘制出了江苏沿海互花米草的分布图。此外,就互花米草盐沼对江苏沿海湿地植被演替的影响进行了讨论。     

NaCl对大米草(Spartina anglica Hubbard)幼苗游离氨基酸成分和脯氨酸含量的影响

用NaCI溶液培养15天的大米草幼苗,脯氨酸积累较双蒸水培养的多。同时随着溶液中NaCl浓度的增高,脯氨酸的积累也增加。用双蒸水和NgCl溶液交替培养的结果表明,大米草幼苗中脯氨酸的含量与溶液的盐度有着密切相关。     

互花米草(Spartina alterniflora)草场土壤微生物生态分布及某些酶活性的研究

种植互花米草的盐沼土中,细菌、放线菌和真菌的数量比对照盐沼土中多。就不同深度来说,15—30厘米土层中,细菌数最多。细菌总数的增减趋势是:夏秋两季最多,冬春两季较少。在各生理类群中,氨化细菌占优势;固氮细菌、硝化细菌次之;反硝化细菌和硫酸盆还原细菌最少。内源呼吸作用强度、添加葡萄糖后的呼吸作用强度、氧化丙酮酸的能力和氧化多酚化合物的能力皆显示出同样的趋势,即三年生草场土壤中生物活性最强,光滩土壤中生物活性最弱。在光滩土壤中,脲酶和过氧化氢酶活性很低,而种植互花米草的土壤中这两种酶活性较强,但与种植年限和季节变化无显著相关性。     

在淡水和海水中大米草(Spartina anglica Hubbard)种子萌发及其游离氨基酸成分的比较

本试验比较了大米草种子在淡水和海水中萌发及其幼苗生长的速度,结果表明,在海水中种子的萌发及幼苗生长速度均不如淡水。同时测定了大米草种子萌发过程中17种游离氨基酸,其含量绝大部分随着萌发的进程而不断增加。种子中不含酪氨酸和苏氨酸,萌发后出现。同一萌发时期在海水中的胚乳含有脯氨酸,而淡水中则不含脯氨酸。     

Ammonium nutrition in the halophyte Spartina alterniflora under salt stress: evidence for a priming effect of ammonium?

Background and aims

The effects of salt stress on the salt marsh halophyte Spartina alterniflora have been well documented. However, plant responses to combined salinity and ammonium toxicity and the underlying mechanisms are relatively unknown. The aim of the present investigation was to study the effects of both salinity (0, 200 and 500 mM NaCl) and nitrogen form (NO₃ ^?, NH₄ ⁺ or NH₄NO₃) on S. alterniflora.

Methods

Plants were cultivated in sandy soil under greenhouse conditions for 3 months. At harvest, growth parameters were measured and leaf samples were analysed for oxidative stress parameters (malondialdehyde, MDA; electrolyte leakage, EL; and hydrogen peroxide, H₂O₂ concentration) and the activity of antioxidant enzymes (glutathione reductase, GR; superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX and Guaiacol peroxidase, GPX).

Results

In the absence of NaCl, plant growth rate was the highest in the medium containing both nitrogen forms, and the lowest in the medium containing only nitrate. Irrespective of the nitrogen form, plant growth was generally higher at 200 mM NaCl than without salinity. Ammonium-fed plants showed better growth than nitrate-fed plants under high salinity. In the absence of salinity, ammonium-fed plants showed higher SOD, APX, GR, CAT, and GPX activities than nitrate-fed ones. The antioxidant enzymes exhibited higher activity in saline-treated plants. The considerable advantage of NH₄ ⁺ nutrition to S. alterniflora under saline conditions was associated with high antioxidant enzyme activities, together with low MDA content, EL, and H₂O₂ concentration.

Conclusion

These data clearly demonstrate that NH₄ ⁺ is more favourable for the growth of S. alterniflora under high salinity than NO₃ ^?. It is suggested that NH₄ ⁺ nutrition improves the plant’s capacity to limit oxidative damage by stimulating the activities of the major antioxidant enzymes.     

Does the effect of flowering time on biomass allocation across latitudes differ between invasive and native salt marsh grass Spartina alterniflora?

1. Parallel latitudinal clines in flowering time have been documented in both the invasive and native ranges of plants. Furthermore, flowering time has been found to affect biomass at maturity. Therefore, understanding how these flowering times affect biomass accumulation across latitudes is essential to understanding plant adaptations and distributions.
2. We investigated and compared trends in first flowering day (FFD), aboveground biomass (AGB), belowground biomass (BGB), and BGB:AGB ratio of the salt marsh grass Spartina alterniflora along latitudinal gradients from the invasive (China, 19–40°N) and native range (United States, 27–43°N) in a greenhouse common garden experiment, and tested whether FFD would drive these divergences between invasive and native ranges.
3. The invasive populations produced more (~20%, ~19%) AGB and BGB than native populations, but there were no significant differences in the FFD and BGB:AGB ratio. We found significant parallel latitudinal clines in FFD in both invasive and native ranges. In addition, the BGB:AGB ratio was negatively correlated with the FFD in both the invasive and native ranges but nonsignificant in invasive populations. In contrast, AGB and BGB increased with latitude in the invasive range, but declined with latitude in the native range. Most interestingly, we found AGB and BGB positively correlated with the FFD in the native range, but no significant relationships in the invasive range.
4. Our results indirectly support the evolution of increased competitive ability hypothesis (EICA) that S. alterniflora has evolved to produce greater AGB and BGB in China, but the flowering and allocation pattern of native populations is maintained in the invasive range. Our results also suggest that invasive S. alterniflora in China is not constrained by the trade‐off of earlier flowering with smaller size, and that flowering time has played an important role in biomass allocation across latitudes.

     

Tidal and seasonal effects on survival rates of the endangered California clapper rail: does invasive Spartina facilitate greater survival in a dynamic environment?

Invasive species frequently degrade habitats, disturb ecosystem processes, and can increase the likelihood of extinction of imperiled populations. However, novel or enhanced functions provided by invading species may reduce the impact of processes that limit populations. It is important to recognize how invasive species benefit endangered species to determine overall effects on sensitive ecosystems. For example, since the 1990s, hybrid Spartina (Spartina foliosa × alterniflora) has expanded throughout South San Francisco Bay, USA, supplanting native vegetation and invading mudflats. The endangered California clapper rail (Rallus longirostris obsoletus) uses the tall, dense hybrid Spartina for cover and nesting, but the effects of hybrid Spartina on clapper rail survival was unknown. We estimated survival rates of 108 radio-marked California clapper rails in South San Francisco Bay from January 2007 to March 2010, a period of extensive hybrid Spartina eradication, with Kaplan–Meier product limit estimators. Clapper rail survival patterns were consistent with hybrid Spartina providing increased refuge cover from predators during tidal extremes which flood native vegetation, particularly during the winter when the vegetation senesces. Model averaged annual survival rates within hybrid Spartina dominated marshes before eradication (? = 0.466) were greater than the same marshes posttreatment (? = 0.275) and a marsh dominated by native vegetation (? = 0.272). However, models with and without marsh treatment as explanatory factor for survival rates had nearly equivalent support in the observed data, lending ambiguity as to whether hybrid Spartina facilitated greater survival rates than native marshland. Conservation actions to aid in recovery of this endangered species should recognize the importance of available of high tide refugia, particularly in light of invasive species eradication programs and projections of future sea-level rise.     

Remedial habitat creation: does Nereis diversicolor play a confounding role in the colonisation and establishment of the pioneering saltmarsh plant, Spartina anglica?

Increasing concerns over global warming and expected sea level rises have led to the adoption of new coastal management strategies around the south-east coast of England. This paper explores the role played by the estuarine invertebrate Nereis diversicolor in limiting the colonisation and establishment of the invasive pioneering salt marsh plant, Spartina anglica. The biology of N. diversicolor is briefly reviewed and data from field experiments are presented demonstrating significant negative effects of worm abundance on transplanted S. anglica biomass. Laboratory-based experiments demonstrated significant negative effects of N. diversicolor abundance on the survival of S. anglica seeds transplanted to sediment cores. The importance of estuarine invertebrates in engineering the mudflat habitat may confound the foreseen ecosystem services and function provided by saltmarsh management schemes. Received: 15 February 1999 / Received in revised form: 4 June 1999 / Accepted: 11 June 1999     

Overexpression of a nascent polypeptide associated complex gene (SaβNAC) of Spartina alterniflora improves tolerance to salinity and drought in transgenic Arabidopsis

Salinity and drought are the most important environmental constraints limiting crop growth and productivity. Here, we have characterized a gene 'SaβNAC' encoding the β subunit of nascent polypeptide associated complex from a halophyte Spartina alterniflora and investigated its role toward abiotic stress regulation. Expression of SaβNAC was differentially regulated by abiotic stresses, including salinity, drought, cold, and ABA in leaves and roots of S. alterniflora. Constitutive over-expression of SaβNAC in Arabidopsis exhibited normal growth under non-stress conditions but enhanced tolerance to salt and drought stresses. Transgenic SaβNAC Arabidopsis retained more chlorophyll, proline, and showed improved ionic homeostasis with less damage under stress conditions compared to WT plants. This is a first report to demonstrate the involvement of βNAC in imparting abiotic stress tolerance which might be due to protection of the newly synthesized polypeptides involved in various stress tolerance mechanisms from abiotic stress induced damage and inhibition of cell death in plant.