TY - JOUR

T1 - Increasing effects of chronic nutrient enrichment on plant diversity loss and ecosystem productivity over time

AU - Seabloom, E.W.

AU - Adler, P.B.

AU - Alberti, J.

AU - Biederman, L.

AU - Buckley, Y.M.

AU - Cadotte, M.W.

AU - Collins, S.L.

AU - Dee, L.

AU - Fay, P.A.

AU - Firn, J.

AU - Hagenah, N.

AU - Harpole, W.S.

AU - Hautier, Y.

AU - Hector, A.

AU - Hobbie, S.E.

AU - Isbell, F.

AU - Knops, J.M.H.

AU - Komatsu, K.J.

AU - Laungani, R.

AU - MacDougall, A.

AU - McCulley, R.L.

AU - Moore, J.L.

AU - Morgan, J.W.

AU - Ohlert, T.

AU - Prober, S.M.

AU - Risch, A.C.

AU - Schuetz, M.

AU - Stevens, C.J.

AU - Borer, E.T.

PY - 2021/2/1

Y1 - 2021/2/1

N2 - Human activities are enriching many of Earth’s ecosystems with biologically limiting mineral nutrients such as nitrogen (N) and phosphorus (P). In grasslands, this enrichment generally reduces plant diversity and increases productivity. The widely demonstrated positive effect of diversity on productivity suggests a potential negative feedback, whereby nutrient-induced declines in diversity reduce the initial gains in productivity arising from nutrient enrichment. In addition, plant productivity and diversity can be inhibited by accumulations of dead biomass, which may be altered by nutrient enrichment. Over longer time frames, nutrient addition may increase soil fertility by increasing soil organic matter and nutrient pools. We examined the effects of 5–11 yr of nutrient addition at 47 grasslands in 12 countries. Nutrient enrichment increased aboveground live biomass and reduced plant diversity at nearly all sites, and these effects became stronger over time. We did not find evidence that nutrient-induced losses of diversity reduced the positive effects of nutrients on biomass; however, nutrient effects on live biomass increased more slowly at sites where litter was also increasing, regardless of plant diversity. This work suggests that short-term experiments may underestimate the long-term nutrient enrichment effects on global grassland ecosystems.

AB - Human activities are enriching many of Earth’s ecosystems with biologically limiting mineral nutrients such as nitrogen (N) and phosphorus (P). In grasslands, this enrichment generally reduces plant diversity and increases productivity. The widely demonstrated positive effect of diversity on productivity suggests a potential negative feedback, whereby nutrient-induced declines in diversity reduce the initial gains in productivity arising from nutrient enrichment. In addition, plant productivity and diversity can be inhibited by accumulations of dead biomass, which may be altered by nutrient enrichment. Over longer time frames, nutrient addition may increase soil fertility by increasing soil organic matter and nutrient pools. We examined the effects of 5–11 yr of nutrient addition at 47 grasslands in 12 countries. Nutrient enrichment increased aboveground live biomass and reduced plant diversity at nearly all sites, and these effects became stronger over time. We did not find evidence that nutrient-induced losses of diversity reduced the positive effects of nutrients on biomass; however, nutrient effects on live biomass increased more slowly at sites where litter was also increasing, regardless of plant diversity. This work suggests that short-term experiments may underestimate the long-term nutrient enrichment effects on global grassland ecosystems.

KW - biodiversity

KW - community ecology

KW - ecosystem ecology, grasslands

KW - NutNet

KW - nutrient network

U2 - 10.1002/ecy.3218

DO - 10.1002/ecy.3218

M3 - Journal article

VL - 102

JO - Ecology

JF - Ecology

SN - 0012-9658

IS - 2

M1 - e03218

ER -