Infestation of improved grasslands by Juncus effusus L. in the catchment of the River Tyne, Northern England: a field survey

Abstract

AbstractSoft rush, Juncus efffusus L., is a widespread weed of managed grasslands. In 1991, a sample‐based field survey of the weed's distribution in improved grasslands was conducted within the catchment of the River Tyne in Northern England. The land classes of the Institute of Terrestrial Ecology (ITE) environmental landscape classification system were used as sampling strata. In total, 182 I‐km grid squares were surveyed. Areas of improved grassland and levels of J. effusus infestation differed significantly between land classes, but there was also wide variation between grid squares within land classes. Most squares within a land class had no J. effusus, while a proportion had large areas. Extra‐polation from the sample data suggested that an area equivalent to 24·0% of the 3000km2 land surface of the catchment supported improved grassland, of which 3·5% was infested with the rush. Infestation of improved grassland was estimated to be lowest in the lowlands (2·0% of improved grassland), intermediate in the marginal uplands (3·0% of improved grassland) and greatest in the uplands (10·8% of improved grassland). Data from the Farm Business Survey, on broad patterns of utilization of improved grassland for hay, silage and livestock in lowland, marginal upland, and upland landscapes in the catchment, do not readily explain the observed variation in infestation levels, which may reflect local factors and the availability of propagules from adjacent rough grazing land.