TY - JOUR

T1 - Simulated nitrogen deposition effects on soil fauna from a semiarid Mediterranean ecosystem in central Spain

AU - Ochoa-Hueso, Raúl

AU - Rocha, Iluminada

AU - Stevens, Carly

AU - Manrique, Esteban

AU - Luciañez, María José

PY - 2014/1

Y1 - 2014/1

N2 - Nitrogen (N) deposition is a major threat to the semiarid Mediterranean ecosystems. We simulated a gradient of N deposition (0, 10, 20 and 50 kg N ha−1 year−1 + 6.4 kg N ha−1 year−1 ambient deposition) in a Mediterranean shrubland from central Spain. In autumn 2011 (after 4 years of experimental duration), soil cores were taken to extract the soil fauna. Acari (45.54%) and Collembola (44.00%) were the most represented taxonomical groups, and their abundance was negatively related to soil pH. Simulated N deposition had an impact on the total number of individuals in soil as well as on Collembola and Pauropoda abundance. Collembola abundance increased with N loads up to 20 kg N ha-1 year-1 and then decreased. This response was attributed to soil acidification (between 0 and 20 kg N ha-1 year-1) and increased soil ammonium (between 20 and 50 kg N ha-1 year-1). Pauropoda were favoured by additions of 50 kg N ha-1 year-1, and it was the only taxonomical group whose abundance was exclusively related to N deposition, suggesting their potential as bioindicators. Contrary to predictions, there was a negative relationship between soil faunal abundance and plant diversity. In conclusion, soil faunal communities from semiarid Mediterranean ecosystems in central Spain seem to be primarily influenced by soil chemistry (mainly pH) but are also susceptible to increased N deposition. The main drivers of change under increased N deposition scenarios seem to be soil acidification and increased ammonium in soils where nitrate is the dominant mineral N form.

AB - Nitrogen (N) deposition is a major threat to the semiarid Mediterranean ecosystems. We simulated a gradient of N deposition (0, 10, 20 and 50 kg N ha−1 year−1 + 6.4 kg N ha−1 year−1 ambient deposition) in a Mediterranean shrubland from central Spain. In autumn 2011 (after 4 years of experimental duration), soil cores were taken to extract the soil fauna. Acari (45.54%) and Collembola (44.00%) were the most represented taxonomical groups, and their abundance was negatively related to soil pH. Simulated N deposition had an impact on the total number of individuals in soil as well as on Collembola and Pauropoda abundance. Collembola abundance increased with N loads up to 20 kg N ha-1 year-1 and then decreased. This response was attributed to soil acidification (between 0 and 20 kg N ha-1 year-1) and increased soil ammonium (between 20 and 50 kg N ha-1 year-1). Pauropoda were favoured by additions of 50 kg N ha-1 year-1, and it was the only taxonomical group whose abundance was exclusively related to N deposition, suggesting their potential as bioindicators. Contrary to predictions, there was a negative relationship between soil faunal abundance and plant diversity. In conclusion, soil faunal communities from semiarid Mediterranean ecosystems in central Spain seem to be primarily influenced by soil chemistry (mainly pH) but are also susceptible to increased N deposition. The main drivers of change under increased N deposition scenarios seem to be soil acidification and increased ammonium in soils where nitrate is the dominant mineral N form.

KW - Acidification

KW - Ammonium

KW - Critical N load

KW - Eutrophication

KW - N deposition

KW - Plant diversity

KW - Soil faunal community

U2 - 10.1007/s00374-013-0838-y

DO - 10.1007/s00374-013-0838-y

M3 - Journal article

VL - 50

SP - 191

EP - 196

JO - Biology and Fertility of Soils

JF - Biology and Fertility of Soils

SN - 0178-2762

IS - 1

ER -