Ectomycorrhizal fungal communities of native and non-native Pinus and Quercus species in a common garden of 35-year-old trees

Non-native tree species have been widely planted or have become naturalized in most forested landscapes. It is not clear if native trees species collectively differ in ectomycorrhizal fungal (EMF) diversity and communities from that of non-native tree species. Alternatively, EMF species community similarity may be more determined by host plant phylogeny than by whether the plant is native or non-native. We examined these unknowns by comparing two genera, native and non-native Quercus robur and Quercus rubra and native and non-native Pinus sylvestris and Pinus nigra in a 35-year-old common garden in Poland. Using molecular and morphological approaches, we identified EMF species from ectomycorrhizal root tips and sporocarps collected in the monoculture tree plots. A total of 69 EMF species were found, with 38 species collected only as sporocarps, 18 only as ectomycorrhizas, and 13 both as ectomycorrhizas and sporocarps. The EMF species observed were all native and commonly associated with a Holarctic range in distribution. We found that native Q. robur had ca. 120% higher total EMF species richness than the non-native Q. rubra, while native P. sylvestris had ca. 25% lower total EMF species richness than non-native P. nigra. Thus, across genera, there was no evidence that native species have higher EMF species diversity than exotic species. In addition, we found a higher similarity in EMF communities between the two Pinus species than between the two Quercus species. These results support the naturalization of non-native trees by means of mutualistic associations with cosmopolitan and novel fungi

Visually evoked slow eye movements, visual-vestibular interaction, and infratentorial lesions

The maximum velocity gain of smooth pursuit and optokinetic, vestibular, and optovestibular slow phases was examined in 15 patients with pontine, 10 with medullary, 10 with cerebellar, and 5 with combined cerebello-brain stem disorders. Marked dissociations were observed between smooth pursuit and optokinetic slow phases, especially in medullary disease. A cerebellar deficit enhanced slow phase velocity gain during rotation in darkness, whereas the corresponding gain during rotation in light was normal

Ecological relationships between phytoplankton communities and different spatial scales in European reservoirs: implications at catchment level monitoring programmes

Phytoplankton communities are structured by factors acting over temporal and spatial scales. Identifying which factors are driving spatial patterns in aquatic communities is the central aim of ecology. In this study, data sets of phytoplankton communities and nvironmental data of two Portuguese servoirs types (lowland ‘‘riverine reservoirs’’ and higher altitude ‘‘artificial lake reservoirs’’) were used to determine the importance of environmental variables at different spatial (geographical, regional and local) and time scales (seasons, years) on the community tructure. In all the data sets, the multivariate ordination techniqu

Automatic and strategic volitional saccadic eye movements in psychotic patients

“The original publication is available at www.springerlink.com”. Copyright Springer DOI: 10.1007/BF01739740 [Full text of this article is not available in the UHRA]Drug-free schizophrenics were compared with depressive psychotics and normal controls on two saccade initiation tasks which differed with respect to the type of stimulus that initiated a saccadic response. Strategic initiation (SIS) appears to use a route different from that in automatic initiation (AIS). The SIS task revealed slowed responding in psychiatrically ill patients if their cognition was impaired, but all groups responded similarly on the AIS task. Schizophrenics could be separated from depressed psychotics by their inability to utilize temporal redundancy to speed up saccade initiation on the SIS task. Neurophysiological evidence implicates specific impairments in the frontal eye field (FEF) and/or basal ganglia.Peer reviewe