TY - JOUR

T1 - Interactive effects of nitrogen deposition and climate change on a globally rare forest geophyte

AU - Ohse, Bettina

AU - Jansen, Doris

AU - Härdtle, Werner

AU - Fichtner, Andreas

N1 - Publisher Copyright: © 2024 The Author(s). Plant Biology published by John Wiley & Sons Ltd on behalf of German Society for Plant Sciences, Royal Botanical Society of the Netherlands.

PY - 2024

Y1 - 2024

N2 - Nitrogen (N) deposition and climate change are both known to threaten global biodiversity. However, we still have a limited understanding of how interactions between these global change drivers affect individuals and populations of specialist species, such as geophytes, within their natural habitat. We explored possible interactive effects of N, drought, and warming on population vitality (mean leaf length, leaf density, flowering probability) and morpho-physiological traits (e.g., leaf and bulb size, N allocation to leaves and bulbs) of the globally rare forest geophyte Gagea spathacea (Liliaceae) in deciduous forests of northern Germany by applying experimental N addition across a climate gradient over a 5-year period. Mean leaf growth and leaf density were not affected by N addition but were enhanced by warmer and drier conditions in the months before leaf emergence. N addition increased N allocation of individual plants towards their subterranean bulbs. Importantly, effects of N addition on morpho-physiological traits depended on warming and drought, with N-fertilized plants showing increased leaf length and decreased specific leaf and bulb N concentration after drier autumns and warmer winters. This indicates that N deposition may partially compensate for increased N demands during warming-induced growth, although this growth-promoting interaction effect is not (yet) reflected in population vitality. Our results highlight the importance of considering multiple global environmental change drivers and a whole plant perspective (above- and belowground traits) to predict long-term growth responses of (endangered) forest spring geophytes and to develop adapted long-term protection strategies.

AB - Nitrogen (N) deposition and climate change are both known to threaten global biodiversity. However, we still have a limited understanding of how interactions between these global change drivers affect individuals and populations of specialist species, such as geophytes, within their natural habitat. We explored possible interactive effects of N, drought, and warming on population vitality (mean leaf length, leaf density, flowering probability) and morpho-physiological traits (e.g., leaf and bulb size, N allocation to leaves and bulbs) of the globally rare forest geophyte Gagea spathacea (Liliaceae) in deciduous forests of northern Germany by applying experimental N addition across a climate gradient over a 5-year period. Mean leaf growth and leaf density were not affected by N addition but were enhanced by warmer and drier conditions in the months before leaf emergence. N addition increased N allocation of individual plants towards their subterranean bulbs. Importantly, effects of N addition on morpho-physiological traits depended on warming and drought, with N-fertilized plants showing increased leaf length and decreased specific leaf and bulb N concentration after drier autumns and warmer winters. This indicates that N deposition may partially compensate for increased N demands during warming-induced growth, although this growth-promoting interaction effect is not (yet) reflected in population vitality. Our results highlight the importance of considering multiple global environmental change drivers and a whole plant perspective (above- and belowground traits) to predict long-term growth responses of (endangered) forest spring geophytes and to develop adapted long-term protection strategies.

KW - Biodiversity

KW - forest herb

KW - Gagea spathacea

KW - global change

KW - interaction effects

KW - N allocation

KW - spring geophyte

KW - Biology

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=85212937886&partnerID=8YFLogxK

U2 - 10.1111/plb.13758

DO - 10.1111/plb.13758

M3 - Journal articles

AN - SCOPUS:85212937886

JO - Plant Biology

JF - Plant Biology

SN - 1435-8603

ER -