Elephants,termites and mound thermoregulation in a progressively warmer world     

Grant S. Joseph  Colleen L. Seymour  Bernard W. T. Coetzee  Mduduzi Ndlovu  Luana Deng  Kelly Fowler  James Hagan  Brian J. Brooks  Jackson A. Seminara  Stefan H. Foord 《Landscape Ecology》2018,33(5):731-742

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Persistence and habitat associations of Purple Martin roosts quantified via weather surveillance radar     

Eli S. Bridge  Sandra M. Pletschet  Todd Fagin  Phillip B. Chilson  Kyle G. Horton  Kyle R. Broadfoot  Jeffrey F. Kelly 《Landscape Ecology》2016,31(1):43-53

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Characterization of Populations of Rhizoctonia solani in Paddy Rice Fields in Côte d'Ivoire     

Banniza S  Sy AA  Bridge PD  Simons SA  Holderness M 《Phytopathology》1999,89(5):414-420

ABSTRACT Isolates of Rhizoctonia solani were obtained from plant and soil samples that had been systematically collected in a field experiment in C?te d'Ivoire to study the diversity of the pathogen and the influence of three different rice rotations on the pathogen population. Characterization by morphology, anastomosis testing, pathogenicity testing, and restriction fragment length polymorphisms (RFLPs) of AT-rich DNA (AT-DNA) showed that there were no differences in isolates from different experimental plots, suggesting that the soil as well as the plant population of the fungus was indistinguishable throughout the experiment and was not influenced by crop rotation. Analysis of AT-DNA showed that the isolates obtained from plant material and one from soil shared a distinct banding pattern, identical with the AT-DNA RFLP obtained for the reference strain of anastomosis group 1 (AG-1). The remaining soil isolates produced a consistent RFLP pattern that was distinct from that of the plant isolates. Morphological characterization of isolates produced two major clusters consisting of the same groups of isolates as found by AT-DNA RFLP. Diversity in morphological characters was much higher in plant than in soil isolates and indicated that the population might consist of several clones. Anastomosis testing revealed that soil as well as plant isolates were able to fuse with the tester strain of AG-1. Significant differences in disease severity were observed between the two groups of isolates in pathogenicity tests on rice plants, with plant isolates being distinctively more virulent.  相似文献   

Population development within the coffee wilt pathogen Gibberella xylarioides reflects host-related divergence     

A. G. Buddie  J. Crozier  M. A. Rutherford  J. Flood  P. D. Bridge 《European journal of plant pathology / European Foundation for Plant Pathology》2015,142(2):291-304

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Cultivars of canola respond similarly to applied nitrogen in n-deficient soils of south Western Australia     

Mark Seymour  Ross F. Brennan 《Journal of plant nutrition》2017,40(18):2631-2649

Six cultivars of canola (Brassica napus L.) were grown with six levels of applied nitrogen (N) fertilizer (urea 46% N) at six locations in south Western Australia (SWA) during 2010 and 2011. The aim of the experiment was to determine if the seed yield (SY) increase (response) of the canola and associated herbicide technologies were different to applied N. Open pollinated (OP) and hybrid cultivars of associated herbicide technologies (Triazine Tolerant, TT; Roundup Ready, RR; Clearfield, CL) were used. Varieties had large SY differences with no N applied. Generally, RR hybrid of 2011 tended to have the highest SY, except for Katanning 2011 where several varieties obtained the same SY. The average amount of N required for 90% of the maximum SY was 113 kg N ha^?1 and economic breakeven N rates were less than or equal to 100 kg applied N ha^?1. The average rate of return on investment in fertilizer N was $1.60.

In four out of six experiments RR hybrids had the highest oil concentration with no applied N. N decreased the oil concentration in all canola types, except at Gibson 2010. At Gibson in 2010, N application increased the oil concentration to about 100 kg N ha^?1 with further additions of N decreasing the oil concentration. There was a linear relationship where N application decreased the oil concentration and increased protein concentration of the seed. In this study, the summation of oil percentage and protein concentration in the seed was on average 65%, with RR hybrids producing 67%.

In most aspects, RR hybrids outperformed RR, OP and other canola types; however, hybrid TT and hybrid CL canola did not consistently outperform their OP counterpart. We suggest that current N fertilizer recommendation models are useful for all canola types currently grown in SWA; however, adjustments should be made to take into account the higher SY and oil concentration potential of RR hybrids compared to TT canola at every rate of applied N.  相似文献   

Decaying wood and tree regeneration in the Acadian Forest of Maine,USA     

Jamie K. Weaver  Laura S. Kenefic  Robert S. Seymour  John C. Brissette 《Forest Ecology and Management》2009

We examined the effect of management history on the availability of decayed downed wood and the use of downed wood as a regeneration substrate in mixed-species stands in the Acadian Forest of Maine. Regeneration of red spruce (Picea rubens Sarg.), eastern hemlock (Tsuga canadensis (L.) Carr.), balsam fir (Abies balsamea L. Mill), and red maple (Acer rubrum L.) was quantified. Treatments included variants of selection cutting, commercial clearcutting (unregulated harvesting), and no harvesting for >50 years (reference). Area of wood substrate (wood ≥ Decay Class III and ≥10 cm on at least one end) was less in the commercial clearcut than in the reference; other treatments were not differentiated. Spruce and hemlock seedlings were found at higher densities on wood than paired forest floor plots of equal area, regardless of treatment. Conversely, fir and maple were less abundant on wood than forest floor plots in reference and selection treatments, but more or equally abundant on wood than forest floor plots in the commercial clearcut. These findings suggest that silvicultural treatment affects both the availability of decayed downed wood and seedling-substrate relationships, and that forest management in the Acadian Region should consider availability of downed woody material.  相似文献   

Genetic diversity of Ganoderma in oil palm plantings   总被引：1，自引：0，他引：1  

Miller  Holderness  Bridge  Chung  & Zakaria 《Plant pathology》1999,48(5):595-603

Isolates of Ganoderma spp. associated with basal stem rot of oil palm were obtained by sampling from two palm plantings in Malaysia. Members of a subset of these were compared using a combination of somatic incompatibility and molecular genetic analyses. Incompatibility interactions between heterokaryons in culture indicated that Ganoderma generally occurred as numerous distinct strains, with compatible strains usually confined to individual palms. Analysis of restriction fragment length polymorphisms (RFLPs) in presumptive mitochondrial DNA (mtDNA) revealed heterogeneity among isolates from neighbouring palms, and from within individual palms. The combination of mtDNA variability and somatic incompatibility suggests that Ganoderma BSR does not spread by direct root-to-root contact between palms. The results may indicate infection spread through basidiospore dispersal or through contact with a heterogeneous long-term residual inoculum in debris.  相似文献   

Large termitaria act as refugia for tall trees,deadwood and cavity-using birds in a miombo woodland   总被引：1，自引：1，他引：0  

Grant S. Joseph  Graeme S. Cumming  David H. M. Cumming  Zacheus Mahlangu  Res Altwegg  Colleen L. Seymour 《Landscape Ecology》2011,26(3):439-448

Landscape heterogeneity can play an important role in providing refugia and sustaining biodiversity in disturbed landscapes. Large Macrotermes (Isoptera) termite mounds in miombo woodlands form nutrient rich islands that sustain a different suite of woody plant species relative to the woodland matrix. We investigated the role of termitaria in providing habitat for cavity-using birds in miombo woodlands that had been greatly impacted by elephants and fire, by comparing the availability of habitat favored by cavity-using birds (tall trees, trees with deadwood, and cavities) on and off mounds, and then testing its effect on species richness and abundance of cavity-using birds. We surveyed 48 termitaria paired with 48 woodland matrix sites in the breeding season; and 54 matrix-termitarium pairs in the non-breeding season in Chizarira National Park, Zimbabwe. Generalized linear mixed-effects models showed that termitaria harboured significantly higher densities (ha⁻¹) of habitat components considered important for cavity nesting birds. Density of trees >6 m in height and incidence of trees with deadwood was nearly 10 times greater on mounds than in the matrix, and the density of cavities was nine times higher on mounds compared to the matrix. A model selection procedure showed that termitaria provided refugia for cavity-using birds and contributed to the resilience of bird communities through high on-mound densities of trees with deadwood. Large termitaria thus appear to play an important role in maintaining functionally important components of the avifauna in heavily impacted Miombo woodlands.  相似文献   

Characterization of Armillaria heimii from Africa   总被引：1，自引：0，他引：1  

A. Pérez-Sierra  J.-J. Guillaumin  B. M. Spooner  P. D. Bridge †‡ 《Plant pathology》2004,53(2):220-230

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Potato notes     

C. Tice  W. C. Edmundson  W. Stuart  Seymour Bridge  Glen Carter  A. G. Allen  Daniel Dean  H. H. Zimmerly  J. O. Milward 《American Journal of Potato Research》1924,1(6):93-98

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