Plant diversity, productivity and nutritive value change following abandonment of public pastures in Japan

We describe changes in plant diversity and productivity after the abandonment of public pastures in Japan. We surveyed the plant community and collected plant and soil samples from 22 pastures, including five pastures that had been abandoned up to 13 years earlier. Chemical analysis revealed forage nutritive values and soil nutrient levels. Overall, plant diversity did not change over time, but productivity and forage nutritive values both decreased significantly after pasture abandonment. These changes can be explained by (i) lower soil nitrate-nitrogen contents due to leaching and (ii) the replacement of sown grasses by native species. Our results suggest that it will become more difficult to restore pasture for grazing as the duration of abandonment increases and that reintroduction of livestock grazing in the abandoned pastures without re-sowing exotic grasses could contribute to biodiversity conservation and maintaining productivity and nutritive values.