A particular issue arose from the increasing spread of brush, notably hazel, but also blackthorn and hawthorn. These colonised more of the limestone area as a result of reduced grazing by cattle and goats. The increasing industrialization of agriculture and the introduction of different breeds of cattle led to shifts in cattle-raising practices – away from winter grazing, which kept down new growth, and towards supplementary feeding. In addition, in the past saplings were often pulled from fields by hand to maintain grazing areas. Trees also used to be harvested for firewood, hazel rods were used for thatching as well as for fence- and basket-making. As these practices ceased, the brush advanced. This notably reduces biodiversity in the affected areas.