Helen Sheridan

The role of grassland sward islets in the distribution of arthropods in cattle pastures.

1. It is well documented that cattle reduce their grazing activity in the vicinity of cattle dung, which gives rise to distinct patches, or islets as they have been termed, of longer sward. The influence of such islets on pasture utilisation and agronomic performance has been widely studied, but very little information is available concerning their influence on grassland biodiversity.

Development of a Sustainably-Competitive Agriculture

The need for both Competitiveness and Sustainability, the two primary overarching goals of EU policy, present the agri-food sector with a unique set of formidable challenges and uncertainties. These point to the need for development of new, quality-focused models for agriculture and food production that are sustainably-competitive. The design criteria for the concept are outlined and developed within the context of an agronomic model for multifunctional, grass-based cattle production systems. This model highlights the importance of harnessing the benefits of functional biodiversity within two key epicenters of the system in order to realise both agronomic and environmental – and hence economic – advantage. Whilst much of the knowledge needed to implement the described model already exists, the functionality of biologically complex rumen and pasture processes within the two key system epicenters, represent the two main pillars of an innovation-driven research programme that is needed to provide fundamental new knowledge necessary to underpin practical development of the model.

The influence of conservation field margins in intensively managed grazing land on communities of five arthropod trophic groups

Abstract.  1. Arthropods, a major component of functional biodiversity within agro‐ecosystems, contribute to sustainability through processes including nutrient cycling and pest control. Extensively managed field margins can help protect this functional biodiversity by providing habitat for beneficial species.

An assessment of bird species within Irish agricultural landscapes using the Field Boundary Evaluation and Grading System

Capsule The Field Boundary Evaluation and Grading System (FBEGS) is a useful predictor of bird populations found in field boundaries located in southeast Ireland. Aims To assess the potential of FBEGS to evaluate the ecological quality of field boundaries in agricultural ecosystems and as a tool for the measurement of bird populations within field boundaries. Methods Surveys of bird populations were made in selected field boundaries on 50 farms in southeast Ireland in winter and during the breeding season. FBEGS surveys were also carried out on field boundaries to assess ecological quality. glms were fitted to assess the utility of the FBEGS Index as a predictor of bird populations. Results The FBEGS Index was an effective predictor of bird populations in the breeding season, but had limited use in predicting bird populations in winter. Within the overall FBEGS Index, the Associated Features score was a good predictor for populations in both the winter and breeding seasons. In addition, the Boundary Structural score of the field boundary was also an accurate predictor of birds in the breeding season. Conclusion The FBEGS Index has high potential for predicting the effect that changes in the farmed landscape will have on bird populations.

Field margins: a comparison of establishment methods and effects on hymenopteran parasitoid communities

Field margins within intensively managed ecosystems are often seen as a last refuge for biodiversity, and are typically targeted with measures within many agri‐environment schemes. Grassland accounts for 81 million ha of land within the EU; however, the ecology of field margins associated with permanent grassland has not been well studied. This study investigated the effects of experimental field margin measures on hymenopteran parasitoid communities over a 5‐year period. Hymenopteran parasitoids were chosen because they occupy high trophic levels, feed on a diverse range of plant and invertebrate hosts, and are considered good indicators of arthropod diversity. Establishment methods included: fencing, natural regeneration, and reseeding with a wildflower mixture, at three margin widths. Field margin establishment method had a significant effect on abundance of parasitoids. Establishment method did not have a significant effect on parasitoid genera diversity, but did affect parasitoid community composition. Margin width had no significant impact on parasitoid communities. Grazing had a significant negative effect on parasitoid genus richness and community structure. This suggests that structural diversity of vegetation plays an important role in parasitoid community structure. Plant species richness did not significantly affect parasitoid abundance or genera richness. Noxious species within plots resulted in a significantly greater abundance and diversity of parasitoids and of idiobionts in particular. Where plant species richness is limited, simple measures such as fencing of narrow field margins may be as effective at increasing parasitoid taxon richness and abundance (indicators of arthropod richness and abundance) as expensive measures such as reseeding and wider margin widths.

Botanical rejuvenation of field margins and benefits for invertebrate fauna on a drystock farm in County Longford.

This study investigates methods to rejuvenate the fl ora of previously degraded fi eld margins on a pastoral farm in County Longford. We also assess the effects of individual treatments on the abundance of various orders of invertebrates recorded within the experimental plots. Field margin treatments were 1.5m-wide unfenced control margins, 1.5m-wide fenced margins or 3.5m-wide fenced margins. Nutrient inputs were excluded from all of the experimental plots. The botanical composition of the plots was examined on four occasions between 2002 and 2004 using permanent, nested quadrats. Emergence traps were used to measure invertebrate abundance within treatment plots and the main sward. Results indicated that 1) exclusion of nutrient inputs had a positive effect on plant species richness within the fi eld margins; 2) plant species richness decreased with increased distance from the hedgerow; 3) herb species richness was greatest in the 1.5m closest to the hedgerow; 4) greater abundance of invertebrates occurred within the 3.5m-wide margins; 5) successful control of Pteridium aquilinum was achieved through spot treatment with the selective herbicide ‘Asulox’; and 6) a combination of management techniques such as cutting and grazing is likely to enhance plant species richness and facilitate the structural diversity of vegetation that is necessary for many invertebrate taxa.

A comparison of grassland vegetation from three agri-environment conservation measures

Abstract Semi-natural grassland habitats have declined significantly throughout Europe. To halt the decline, grassland conservation measures have been included in most European agri-environment schemes. This is the first study to compare the botanical composition of grassland habitats managed under the Irish Agri-Environment Options Scheme (AEOS). Sixty fields on drystock pastoral farms in receipt of agri-environment payments for grassland conservation were surveyed, with 20 fields being enrolled in each of the following AEOS options: Traditional Hay Meadow (THM), Species-Rich Grassland (SRG) and Natura 2000 species-rich grassland (Natura). The vegetation quality of sites enrolled in the Natura measure was higher than the quality of those enrolled in the THM and SRG measures. Natura sites had the greatest species richness, with a mean >40 species per site, which included approximately 17 species indicative of high botanical quality. Traditional Hay Meadows sites had the lowest species richness (mean: 29 species per site) and were dominated by species associated with improved grassland. Some THM sites had good levels of botanical richness and were similar in composition to Natura sites, with some Natura sites having lower vegetation quality, more similar to that of THM sites. Species-Rich Grassland had botanical richness that was intermediate between THM and Natura sites. A thorough assessment of the effectiveness of these measures was confounded by a lack of quantitative objectives for the target community composition to be attained. We discuss limitations and potential opportunities regarding the design, targeting, implementation and cost-effectiveness of these agri-environment measures.