Given the expansion of plantation forests in Ireland over recent years, there is a need to assess their impact on biodiversity and to identify how sustainable forest management strategies can incorporate biodiversity. We aimed to assess the impact of plantation forests on spider communities and identify structural indicators of their diversity. Pitfall traps were used to sample spiders in Sitka spruce (Picea sitchensis) and ash (Fraxinus excelsior) plantations at different stages of the forest cycle and cover of vegetation, dead wood and soil organic content were measured within each site. Ordinations revealed that spider assemblages were separated by both forest development and canopy species across the forest cycle. The pre-thicket ash and spruce assemblages were similar, whereas canopy species had a greater effect in the more structurally developed stands. The mature ash plots formed a distinct group from the other stands. Overall species richness was highest in the spruce and ash pre-thicket stands, and in the mature spruce stands with a more open canopy.Mature ash stands had the lowest species richness. Lower field layer vegetation was positively correlated with total spider species richness and open habitat specialist species richness whereas canopy closure had a negative effect on these species variables. Forest spider species were positively correlated with litter cover, depth and twig cover. To enhance the diversity of open and forest spider species within a stand, the growth of lower field layer vegetation should be encouraged at all stages of the forest cycle, whilst retaining features typical of a mature forest. Within a plantation, a mosaic of different aged stands will sustain both open and forest specialists to enhance diversity. The distinct assemblages found in the mature plantations indicate that on a landscape scale, the establishment of both ash and spruce plantations will enhance overall diversity.
Coronary artery fistula (CAF) is an anomalous connection between a coronary artery and a major vessel or cardiac chamber. Most of the coronary fistulas are discovered incidentally during angiographic evaluation for coronary vascular disorder. The management of CAF is complicated and recommendations are based on anecdotal cases or very small retrospective series. We present three cases of CAF, two of which were symptomatic due to hemodynamically significant coronary steal phenomenon. They underwent successful transcatheter coil embolization, leading to resolution of their symptoms. Percutaneous closure offers a safe and effective way for the management of symptomatic patients. CAFs are rare cardiac anomalies but can give rise to a variety of symptoms because of their hemodynamic consequences or complications. They should be part of cardiac differential diagnosis particularly in patients without other risk factors. Correction of CAF is indicated if the patients are symptomatic or if other secondary complications develop.
The incidence, clinical features, histogenesis, and treatment of extramammary Paget's disease (EMPD) are reviewed. This unusual skin lesion is associated with an underlying adnexal neoplasm in about 50% of cases. Also, the incidence of distant organ malignancies of EMPD is higher than expected by chance. Even in the absence of a recognizable underlying cancer, EMPD may occasionally produce distant metastases, indicating the malignant potential of this condition. Histochemical, immunohistological, and lectin binding studies demonstrate that the cell of origin of EMPD is the exocrine cell of sweat glands. Although EMPD may arise from eccrine cells, derivation from apocrine cells appears more common. The treatment of the primary lesion, by wide margin excision, is fraught by a high recurrence rate. Chemosurgery may reduce local relapse of EMPD. The value of adjuvant radiation therapy is unestablished. Chemotherapy has induced remission in 2 cases of advanced EMPD and needs testing in clinical trials.
Identification of valid indicators of biodiversity is a critical need for sustainable forest management. We developed compositional, structural and functional indicators of biodiversity for five taxonomic groups-bryophytes, vascular plants, spiders, hoverflies and birds-using data from 44 Sitka spruce (Picea sitchensis) and ash (Fraxinus excelsior) plantation forests in Ireland. The best structural biodiversity indicator was stand stage, defined using a multivariate classification of forest structure variables. However, biodi-versity trends over the forest cycle and between tree species differ among the taxonomic groups studied. Canopy cover was the main structural indicator and affected other struc-tural variables such as cover of lower vegetation layers. Other structural indicators included deadwood and distances to forest edge and to broadleaved woodland. Functional indicators included stand age, site environmental characteristics and management prac-tices. Compositional indicators were limited to more easily identifiable plant and bird species. Our results suggest that the biodiversity of any one of the species groups we surveyed cannot act as a surrogate for all of the other species groups. However, certain subgroups, such as forest bryophytes and saproxylic hoverflies, may be able to act as surrogates for each other. The indicators we have identified should be used together to identify stands of potentially high biodiversity or to evaluate the biodiversity effects of silvicultural management practices. They are readily assessed by non-specialists, ecolog-ically meaningful and applicable over a broad area with similar climate conditions and silvicultural systems. The approach we have used to develop biodiversity indicators, including stand structural types, is widely relevant and can enhance sustainable forest management of plantations.
The target rate of afforestation in Ireland over the next 30 years is 20,000 ha per year, which would result in an increase of the forest cover from the current 10% to 17%. In order to promote sustainable forest management practices, it is essential to know the composition and conservation value of habitats where afforestation is planned and the effects of subsequent planting upon biodiversity. The objectives of this study were to investigate changes in vegetation composition and diversity of grasslands 5 years after afforestation with Sitka spruce (Picea sitchensis) and determine the primary ecological and management factors responsible for these changes. Species cover, environmental and management data were collected from 16 afforested and unplanted improved and wet grassland site pairs in Ireland. Our results indicate that 5 years after tree planting, there were significant changes in richness, composition, and abundance of species. Competitive and vigorous grasses were more abundant in planted than in unplanted sites, as were generalist species found in both open and wooded habitats, while small-stature shadesensitive species were less abundant. Vascular plant species richness and Shannon's diversity index were higher in unplanted wet grassland, than in the planted sites. Bryophyte species richness was higher in planted improved grassland than in unplanted sites. The differences were primarily the result of the exclusion of grazing, ground preparation, changes in nutrient management and drainage for afforestation. Drainage ditches provided a temporary habitat for less competitive species, but the overall effect of drainage was to reduce the diversity of species dependent on wet conditions. Variance partitioning showed differences in the relative influences of environmental and management variables on biodiversity in the two habitats, probably due to the greater pre-afforestation grazing pressure and fertilisation levels in improved grasslands. The differences in biodiversity 123Biodivers Conserv (2008) 17:1057-1072 DOI 10.1007 between planted and unplanted grasslands indicate that afforestation represents a threat to semi-natural habitats where distinctive and highly localised plant communities could potentially occur.
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