Landscape evolution and nutrient rejuvenation reflected in Amazon forest canopy chemistry

Terra firme forests make up more than three quarters of the western Amazon basin and are often considered functionally homogeneous in regional scale mapping and modelling efforts. However, the landforms underlying these systems are subject to dynamic processes of landscape evolution occurring within an otherwise geomorphically stable terrace formation. These processes may introduce systematic variability in local nutrient status of terra firme ecosystems. We utilised high‐resolution airborne topographic and imaging spectroscopy data, with directed field soil surveys, to reveal that active stream incision and patterns of soil rock derived nutrient availability drive foliar canopy chemistry distributions across seven catchments within a single terrace formation. These results strongly suggest that fine‐scale geomorphic processes directly affect biogeochemical cycles throughout the lowland western Amazon. Furthermore, links between landscape evolution and foliar chemical distributions indicate that geomorphic processes drive the fine‐scale spatial organisation of this tropical ecosystem, with implications for the functional assembly and biogeography of Amazonian forests.     

Occurrence of fungal spores in the respiratory tract and homes of patients with positive skin test to fungi

The occurrence of fungal spores in the upper respiratory tract and in the homes of 86 patients with allergic manifestations and positive skin tests for fungi has been investigated.Alternaria tenuis andCladosporium herbarum have been more frequently found to give positive reactions, followed byAspergillus mix,Candida albicans andPenicillium notatum. Cladosporium andAlternaria represented also the most common moulds isolated from nasal specimens. The prevalent fungi isolated from patients' environments wereCladosporium, Penicillium andAlternaria, occurring respectively in 93%, 78% and 72% of the homes sampled. An examination of individual cases have revealed a surprisingly close correlation, in 47 out of 86 patients, between positive skin test response and presence in high amount of the same fungi in patient's respiratory tract and home. In the majority of cases the fungi involved wereAlternaria and/orCladosporium.     

Seasonal airborne pollen pattern in Mar del Plata City, Argentina

Continuous aerobiological survey of the atmosphere of Mar del Plata was carried out from December 1991 to November 1993 with a Burkard volumetric spore trap. Daily slides were prepared and studied every 2 h with standard techniques. Weekly records were kept for 27 relevant pollen types selected either by their prevalence or relative high atmospheric concentration. Quantitative multivariate analysis enabled to distinguish three major pollen seasons, related to atmospheric dominance either arboreal pollen (AP) or non-arboreal pollen (NAP). June to October is the richest period in number of pollen types, mainly dominated by AP; while from November to May, there is an overwhelming dominance of NAP types, represented by grass, herb and weed pollen. The study and prediction of this phenomenon is of great interest not only from the ecosystem point of view, but in relation to human disease as well.     

Transport of microorganisms to Israel during Saharan dust events

Dust storms are serious meteorological events that affect the East Mediterranean region, primarily during the spring season. The physical and chemical nature of dust storms, their origin, and the meteorological conditions leading to the generation of storms have been fully documented, but knowledge on their biological content is almost nonexistent. Four dust events that occurred in the period 2004–2005 were sampled in Haifa, Israel, an urban area on the East Mediterranean coast, for biological characterization. Samples were taken before or after (depending on the meteorological conditions) as well as during the dust events. Dust particles were collected as two size fractions using a dichotomous sampler, and their elemental content was determined using X-ray fluorescence analyses. Airborne bacteria and fungi were collected with the Six Stage Andersen Viable Impactor. Fungi were identified by optical microscopy. Compared to adjacent clear days, there was an increase in the concentration of both atmospheric particles and elements of geological and marine origin during the dust events. The concentration of airborne microorganisms during the dust events was also higher, and the fungal population content was affected. On a winter clear day the abundant airborne fungi were Paecilomyces variotii, Penicillium glabrum, and Alternaria alternata. On a spring clear day, the persisting airborne fungi were Alternaria alternata, Geotrichum candidum, Penicillium chrysogenum, and P. glabrum. However, during two dust events the fungal population was dominated by Alternaria alternata, Aspergillus fumigatus, A. niger, A. thomii, Cladosporium cladosporioides, Penicillium chrysogenum, and P. griseoroseum. This study suggests that Saharan and other desert dust events in the East Mediterranean have a significant effect on the airborne microbial populations, which might impact on health, agriculture, and ecology.     

Pollen calendar for Vigo, North-West Spain (1995)

This is the first data from a pollen survey in Vigo, an Atlantic city in northwest Spain. The pollen calendar for Vigo is presented, as well as the pollination period for the nine most important allergenic plants. Through 1995, 30 083 pollen grains belonging to 52 taxa, were recorded using the Lanzoni VPPS 2000 volumetric spore-trap. The most relevant taxa found were: Urticaceae,Pinus, Poaceae andQuercus (75% of the total pollen),Betula, Castanea, Cupressaceae, Chenopodiaceae, Ericaceae, Myrtaceae,Olea, Plantago, Platanus andRumex (21%), and the final 4% was distributed mainly among pollen types, such as:Corylus, Alnus, Fabaceae, Compositae,Artemisia andCedrus. Of the total annual pollen count, 56% was found in March and April. Another, secondary peak was recorded in June corresponding to the flowering period of herbaceous species. The high pollen total of Urticaceae (7625 grains, 25% of the total) should be highlighted. The percentages ofOlea europaea (565 grains) should be noted as well, taking into account its geographical distribution.     

Airborne concentrations ofBotrytis, Uncinula andPlasmopara spores in a vineyard in Leiro-Ourense (N.W. Spain)

Three important phytopathogenic spores which cause serious fungal diseases on vines (Botrytis, Uncinula andPlasmopara) were monitored from June 2, 1994 to September 21, 1994, in vineyards belonging to ‘Estación de Enoloxía e Viticultura’ of Ponte San Clodio-Leiro (Ourense), one of the most important vine growing areas of northwest of Spain. The concentrations for each of the genera were correlated with rainfall, humidity, maximum, minimum and average temperatures. These meteorological parameters are currently used to determine chemical sprays to be applied to the vines. The aim was to establish the behaviour of airborne concentrations of spores of these taxa during the period from the flowering to harvest because these are the periods of greatest susceptibility to attack by these pathogens.     

三维城市景观生态研究

城市景观元素的三维分析是城市景观研究发展的重要趋势之一。城市形态的结构特征与功能的空间作用不仅体现在二维空间中,同时在三维向度上表现出城市社会经济发展态势与空间演变的相互作用,因此在城市空间格局、过程与功能的讨论中,不能局限于二维平面。首先由三维视角提出城市景观格局及功能网络特征,并结合对航空摄影测量、卫星遥测、机载激光扫描等三维信息获取方法的认识,介绍目前城市景观三维信息提取的相关方法;其次,在三维城市景观生态研究内容方面,重点介绍城市景观要素提取、格局特征及其动态变化、生态环境效应和城市景观功能等相关研究,探讨城市内部的三维建成景观以及绿地景观要素提取与应用,并在传统景观格局分析方法基础上,提出了三维城市景观格局特征测量方法、动态变化监测方法以及动态模拟等相关内容,进一步对三维城市景观在生物多样性、局部气候变化等生态环境效应方面的研究进行了归纳总结;最后借助构建三维景观功能网络的思路,以作为三维城市景观功能优化研究的切入点。     

Prevalence of culturable and non-culturable airborne fungi in a grain store in Delhi

Fungal spores are important aeroallergens and proper knowledge of their qualitative and quantitative prevalence in indoor and outdoor environments is of paramount importance in the study of allergic disorders. The present investigation was aimed at the study of seasonal and annual prevalence of fungi inside a large grain storage facility. Sampling was carried out from September 1989 to August 1991. Although fungal spores occurred throughout the year there was seasonal variation.Aspergillus flavus. Cladosporium spp.Epicoccum nigrum and basidiospores had a definite seasonal pattern.Aspergillus flavus andUstilago (smuts) were the most predominant fungi in the facility. Their concentration was significantly higher (P<0.05) than in outside air. The need to reduce fungal concentration in grain storage is emphasised.     

武汉市武昌地区气传致敏花粉调查研究

应用曝片法连续365d收集武昌地区3个调查点的气传花粉,全年共检出花粉48643粒,分属28个科、属。一年中出现2次花粉高峰,即3～4月份,8～9月份。其中优势花粉为悬铃木属（Platanus）、柏科（Cupressaceae）、松属（Pinus）、蒿属（Artemisia）等;最主要的致敏花粉为蒿属、豚草属（Ambrosia）。对影响本地区空气中花粉飘散的因素,几种优势花粉的致敏特点及其临床意义作了初步探讨。