TY - JOUR

T1 - Nitrogen cycling and storage in Gagea spathacea (Liliaceae)

T2 - ecological insights for protecting a rare woodland species

AU - Fichtner, Andreas

AU - Matthies, Diethart

AU - Armbrust, Malin

AU - Jansen, Doris

AU - Sturm, Knut

AU - Walmsley, David

AU - von Oheimb, Goddert

AU - Härdtle, Werner

PY - 2018/9/1

Y1 - 2018/9/1

N2 - Strategies to globally protect biological diversity are often hampered by an insufficient ecological knowledge about target species. This also applies to Gagea spathacea (Liliaceae), a ‘vulnerable’ woodland spring geophyte with a distribution largely restricted to the lowlands of Central Europe. We studied whether the species’ linkage to highly fertile forest soils is related to its high nitrogen (N) demands during its short developmental cycle. We hypothesized that the species exhibits a highly efficient N (re)cycling strategy, characterized by efficient resorption of N from the leaves and reallocation to bulbs at the end of the growing season. To test this assumption, we conducted a 15N tracer experiment and quantified 15N flows between soil, leaves, bulbs, and roots. Our findings support our hypothesis that G. spathacea is exceptionally efficient in recycling N, shown by the resorption of 68% of leaf N and its reallocation to bulbs at the end of the growing season. After 6 weeks of growth the plant showed a distinct shift in its N metabolism: The C:N ratio of leaves strongly increased and those of bulbs decreased, leaf 15N enrichment and recovery started to decrease, while total plant 15N recovery remained constant, indicating no further N uptake from the soil. Leaf N reallocation to bulbs was accompanied by a twofold increase of the bulbs’ biomass. Because of the stenoecious behaviour of G. spathacea, a careful protection and sustainable management of G. spathacea forest habitats is necessary, particularly in its Central European core area.

AB - Strategies to globally protect biological diversity are often hampered by an insufficient ecological knowledge about target species. This also applies to Gagea spathacea (Liliaceae), a ‘vulnerable’ woodland spring geophyte with a distribution largely restricted to the lowlands of Central Europe. We studied whether the species’ linkage to highly fertile forest soils is related to its high nitrogen (N) demands during its short developmental cycle. We hypothesized that the species exhibits a highly efficient N (re)cycling strategy, characterized by efficient resorption of N from the leaves and reallocation to bulbs at the end of the growing season. To test this assumption, we conducted a 15N tracer experiment and quantified 15N flows between soil, leaves, bulbs, and roots. Our findings support our hypothesis that G. spathacea is exceptionally efficient in recycling N, shown by the resorption of 68% of leaf N and its reallocation to bulbs at the end of the growing season. After 6 weeks of growth the plant showed a distinct shift in its N metabolism: The C:N ratio of leaves strongly increased and those of bulbs decreased, leaf 15N enrichment and recovery started to decrease, while total plant 15N recovery remained constant, indicating no further N uptake from the soil. Leaf N reallocation to bulbs was accompanied by a twofold increase of the bulbs’ biomass. Because of the stenoecious behaviour of G. spathacea, a careful protection and sustainable management of G. spathacea forest habitats is necessary, particularly in its Central European core area.

KW - Ecosystems Research

KW - Ancient woodland

KW - Convention on Biological Diversity

KW - Nitrogen allocation

KW - Nitrogen recycling

KW - 15N

KW - Stable isotope

KW - 15N

KW - Ancient woodland

KW - Convention on Biological Diversity

KW - Nitrogen allocation

KW - Nitrogen recycling

KW - Stable isotope

UR - http://www.scopus.com/inward/record.url?scp=85050905452&partnerID=8YFLogxK

U2 - 10.1007/s11258-018-0863-x

DO - 10.1007/s11258-018-0863-x

M3 - Journal articles

VL - 219

SP - 1117

EP - 1126

JO - Plant Ecology

JF - Plant Ecology

SN - 1385-0237

IS - 9

ER -