张掖黑河湿地附植硅藻群落初步研究 ——以张掖国家湿地公园为例

研究张掖国家湿地公园附植硅藻群落现状,为保护寒、旱区湿地水生植物与生物多样性提供理论依据。2017年夏、秋从张掖国家湿地公园浅水湖泊采集12种常见水生植物,采集植物上附植硅藻,并在水质富营养化评价的基础上进一步分析硅藻的种类分布、优势种、多样性和聚类性。结果表明,张掖国家湿地公园水体轻度富营养化;共检出附植硅藻39属158种(含变种),其中舟形藻属种类最多(18种),其次为菱形藻属(16种)、桥弯藻属(15种)和脆杆藻属(13种);Achnanthedium minutissimum为分布最为广泛的优势种,其次为Ulnaria acus和Encyonopsis subcryptocephala;Shannon-Weaver多样性指数在1.41～3.13,Pielou均匀度指数在0.58～1.07,均是秋季显著高于夏季(P0.05,t-test);Cody指数与聚类分析表明,在同一时期内附植硅藻种类组成的相似程度和优势种分布对部分宿主植物的选择趋于一致,但也有部分宿主植物之间附植硅藻群落结构仍然存在较大差异。     

Residential movements of top predators in Chile’s most isolated marine protected area: Implications for the conservation of the Galapagos shark,Carcharhinus galapagensis,and the yellowtail amberjack,Seriola lalandi

1. Marine protected areas (MPAs) are becoming a widely used tool for the conservation of biodiversity and for fishery management; however, most of these areas are designed without prior knowledge of the basic ecological aspects of the species that they are trying to protect.
2. This study investigated the movement of two top predators: the Galapagos shark, Carcharhinus galapagensis, and the yellowtail amberjack, Seriola lalandi, in and around the Motu Motiro Hiva Marine Park (MMHMP) using MiniPAT satellite tags to determine the effectiveness of this MPA for the protection of these species.
3. The Galapagos sharks (n = 4) spent most of their tag deployment periods inside the MMHMP. However, high intraspecific variability was observed in their movement dynamics. Daily individual maximum movements ranged from 17 to 58 km and the maximum distance from Salas y Gómez Island, the only emergent island within the MMHMP, ranged from 31 to 139 km.
4. The maximum linear distance travelled for a female juvenile Galapagos shark (152 cm total length) was 236 km, which is greater than the maximum distance previously documented for juveniles of this species (<50 km).
5. For the yellowtail amberjack (n = 1), 91% of the satellite geolocations were within the MMHMP, with a maximum daily distance travelled of 6 km. The maximum distance travelled between points was 111 km and the maximum distance from Salas y Gómez Island was 62 km.
6. All archival tagged fish spent most of their time at depths of <50 m and never left the epipelagic zone. Daytime versus night-time differences were pronounced in all individuals but showed high interindividual variability.
7. This study provides a baseline on the movement of these two top predators in the MMHMP and provides valuable insights for the creation of MPAs in the region and elsewhere.

     

Genetic structure of Orbicella faveolata population reveals high connectivity among a marine protected area and Varadero Reef in the Colombian Caribbean

1. The protection of ecosystems with high diversity, such as coral reefs, is not an approach that guarantees their conservation. Thus, maintaining connectivity among coral populations over the long term is a strategy that should be adopted in order to protect diversity and ecological processes. Although coral reefs in Colombia are highly diverse, the population genetics baseline data of keystone species such as Orbicella faveolata are limited.
2. To provide current information about the connectivity between populations of O. faveolata in the Colombian Caribbean, the genetic diversity and distribution of O. faveolata was evaluated with analysis of molecular variance (AMOVA), principal components, and migration estimations using 113 genets distributed in six populations. Also, a genetic structure analysis that included the available data for the Caribbean population was conducted, seeking to understand how the Colombian populations relate to the broader region.
3. According to the global fixation index (F_ST) for the Colombian Caribbean, there was no genetic structure (F_ST = 0.002). Discriminant analysis of principal components (DAPC) showed that Corales del Rosario Archipelago (CR), Este de Isla Fuerte (EIF), San Bernardo Archipelago (SB), and Varadero Reef (VR) were grouped with Oeste de Isla Fuerte (OIF), with Bushnell (BS) representing the most divergent cluster. Migration analysis showed relatively high migration from VR to CR and SB, highlighting the importance of VR as a genetic reservoir for the region. Structure analysis showed that the Colombian population presented a specific genetic identity (F_ST = 0.254), suggesting that the Colombian Caribbean population could be a peripheral population that contributes significantly to genetic variation and is connected through a complex connectivity process.
4. In conclusion, the estimated genetic connectivity reflects the influence of sea surface dynamics over the interpopulation exchange dynamics and the role of protected and nonprotected coral reef in the Colombian Caribbean. Thus, the Colombian Caribbean population of O. faveolata could be relevant to the conservation of genetic diversity on a larger scale.

     

Nearshore fish assemblages associated with introduced predatory fishes in lakes

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Is the decline of birds and amphibians in a steppe lake of northern Patagonia a consequence of limnological changes following fish introduction?

• 1. Laguna Blanca, in Laguna Blanca National Park, is a lake in Patagonia which has been designated as a Ramsar site since 1971 because of bird diversity and abundance and importance for nesting, particularly for the black neck swan, Cygnus melanocoryphus. It is also valued for its populations of endemic amphibians, Atelognathus patagonicus and Atelognathus praebasalticus.
• 2. Avian and amphibian populations have decreased dramatically in recent years. Percichthys colhuapiensis, Percichthys trucha (Pisces, Percichthyidae), Salmo trutta and Oncorhynchus mykiss (Pisces, Salmonidae) were introduced into Laguna Blanca in 1965. Since 1986, no Atelognathus frogs have been found. The abundance of swans and coots, which are strongly associated with macrophytes for nesting and feeding, has diminished drastically, whereas piscivorous birds have increased.
• 3. The fishless condition of some neighbouring small lakes with abundant pond weeds, aquatic birds and endemic amphibians, was assessed in order to compare the physical and chemical characteristics and the quantitative composition of the benthos among lakes. Fish presence at Laguna Blanca and its absence at El Burro, Antiñir and Jabón lakes, were confirmed. Compared with previous results, it seems that the abundance of Amphipoda (Hyalella), Copepoda and Cladocera at Laguna Blanca has decreased, while Acari has increased and Notostraca has disappeared. Water transparency has diminished in Laguna Blanca and now is lower than that of fishless lakes.
• 4. P. colhuapiensis were captured only in Laguna Blanca, with the highest captures in the littoral zone. The population shows rapid individual growth in the early years and an absence of fish older than 6 years. The preponderance of benthos and the presence of macrophytes in the gut contents of adult P. colhuapiensis appear to indicate that they are important consumers of these resources.
• 5. This paper concludes that fish introduction in Laguna Blanca led to a complex trophic cascade effect (fish predation on tadpoles, fish competition for avian food, bottom disturbance, zooplankton reduction) producing deleterious effects on the amphibian and bird populations.

Copyright © 2006 John Wiley & Sons, Ltd.     

内蒙古鄂尔多斯市公园绿地土壤肥力调查与评价

通过土壤样品采集和实验室分析,系统研究鄂尔多斯市公园绿地土壤的化学特性及养分丰缺状况,包括pH值、有机质、全氮、全磷以及有效氮、磷、钾,分析养分因子之间的相关性,评价公园绿地土壤的肥力状况,揭示出鄂尔多斯市公园绿地土壤存在的问题：土壤pH值偏高,其中85.7%的土壤呈强碱性,其余呈碱性;多数土壤有机质、全氮、全磷、碱解氮、有效磷、速效钾含量处于缺乏及以下水平;土壤pH值与有机质、速效钾分别显著和极显著负相关;有机质与其他养分因子之间均极显著相关。     

昆明市月牙潭公园葫芦岛植物应用与配置研究

通过对昆明市月牙潭公园葫芦岛的植物调查,研究其种类组成和在园林绿化中的应用。结果表明：昆明市月牙潭公园葫芦岛有园林植物87种,隶属于47科,68属;乔木、灌木和地被植物分别有36种、40种和11种,乔灌（含地被）比为1∶1.42;常绿植物63种,落叶植物24种,分别占72%和28%;乡土树种22种,引进种14种,分别占总数的61%和39%。并分析了昆明市月牙潭公园植物配置存在的问题,提出了改进的建议。     

福州市西湖公园滨水景观赏析

通过对福州西湖公园滨水景观资源进行调查,首先阐述了公园的滨水景观属性,进而从观赏性、生态性、宜人性等方面对公园的驳岸、植物、园路以及景观小品等要素进行分析;另外还探讨了公园滨水文化的延续与发展,并提出了建议性的思考,以期能为城市滨水景观的营造提供一些参考,为创造更好的人居环境提供依据。     

Urban greenspace access,uses, and values: A case study of user perceptions in metropolitan ravine parks

Urban greenspaces provide critical ecosystem services to urban area residents. While urban greenspaces provide a range of ecosystem services, cultural ecosystem services may be the most prominent to residents. Cultural ecosystem services provide benefits through educational, recreational, social, and spiritual opportunities. More knowledge is required about greenspace users’ perspectives of their local greenspaces, which will enrich park planners’ knowledge of the preferences, concerns, and potential points of conflict that greenspace users experience. To help increase this knowledge, we conducted a survey with closed and open-ended questions and supported it with a park audit and photographic evidence. As a case study, data were collected in six ravine parks in the City of Toronto, Canada. Ravine parks were of particular interest as they are a unique form of socio-ecological greenspace that have varied management goals which on occasion may differ from some user preferences and values. Quantitative data were analyzed with analysis of variance and chi-square tests of independence, and qualitative data were analyzed with conventional qualitative content analysis. Our results highlight that current ravine park users vary widely in their characteristics and the values they pursue through their park access. While the range of ravine park types accommodates some of this variability, there is also conflict between ravine park users with different values and expectations. We are offering a series of recommendations addressing these findings and hope that insights from this deep and rich case study will be of use to other forested, urban greenspaces under similar conditions.     

Exploring preferences for biodiversity and wild parks in Chinese cities: A conjoint analysis study in Hangzhou

There has been a transformation of value orientation from an anthropocentric to eco-centric view in Chinese urban park design. Biodiversity enhancement has been increasingly seen as a prioritised park design aim by landscape designers. This promotes the rise of a novel park style with wild, less manicured appearance in cities, which shows strong contrasts to the traditional park style with ornamental, manicured characteristics. However, in this urban park transformation process, people’s opinion has been almost ignored. This research investigated the importance of biodiversity compared with other relevant urban park attributes (i.e., Facilities, Woodlands, Maintenance, and Seasonal views) identified from preliminary focus groups. The research further predicted preferences between wild and traditional urban parks. Conjoint analysis was used to address these questions. Five urban park attributes (i.e., Biodiversity, Facilities, Woodlands, Maintenance, and Seasonal views) were included in the conjoint questionnaire survey. The survey (N = 187) was conducted with the public and ecology/landscape professionals in Hangzhou, China. Results showed that for professionals, biodiversity was the most important attribute relative to others; for the public, both facilities and biodiversity were the most important attributes. Preferences for the two park styles varied between the two groups: professionals preferred wild parks, whereas the public preferred traditional parks. Yet, public preferences for wild parks were enhanced by improving maintenance levels and providing recreation facilities. The study concluded the appreciation of biodiversity among both the public and professionals. Differences in professional preferences for wild parks compared to the public should be considered when professionals design wild parks in the future.