Abstract
Humans have dramatically increased atmospheric CO2 concentration as well as biologically available nitrogen (N). Nitrogen is an essential nutrient for vegetation growth and N availability represents a limiting factor on carbon (C) sequestration by the terrestrial ecosystems. While there is a large infrastructure for measurements to constrain the C cycle, data to constrain the N cycle are less readily available. Using a combination of remote sensing products (MODIS), canopy N concentration data (ICP forest), plant functional type and environmental variables including soil, climate (WorldClim) and elevation (EU-DEM), we generated a canopy N map across European forests using a random forest statistical method (hereafter RF canopy N map).
Most current Global Vegetation Models (GVMs) have integrated C and N cycles, to account for the link between C and N for plant growth and respiration. Leaf N concentration is also important for other biomass compartments as N allocations are prescribed relative to leaf N. The objective of this study is to compare canopy N of two GVMs, O-CN and LPJ-GUESS, and the RF canopy N map in European forests.
The obtained canopy N maps show contrasting spatial patterns. The RF canopy N map shows higher canopy N values, i.e. between 1.8 and 2.2 %N, in mid-western and eastern Europe, while showing lower values, i.e. 1.2 and 1.6 %N, around the Mediterranean region and in the south of Sweden. The canopy N map obtained from the O-CN simulation shows relatively lower canopy N values, ranging from 1.0 to 1.8 %N, in central and northern Europe, while in the Mediterranean region the values are higher, between 1.8 and 2.4 %N. Similar to the RF map, the LPJ-GUESS canopy N map shows relatively higher canopy N values in mid-western Europe compared to southern and northern Europe, however, the LPJ-GUESS canopy N values show little spatial variation in the Mediterranean region. Also, the LPJ-GUESS values are higher, with canopy N values ranging between 2.0 and 2.8 %N in mid-western Europe, and canopy N values ranging between 1.6 and 1.8 %N in the Mediterranean region.
Most current Global Vegetation Models (GVMs) have integrated C and N cycles, to account for the link between C and N for plant growth and respiration. Leaf N concentration is also important for other biomass compartments as N allocations are prescribed relative to leaf N. The objective of this study is to compare canopy N of two GVMs, O-CN and LPJ-GUESS, and the RF canopy N map in European forests.
The obtained canopy N maps show contrasting spatial patterns. The RF canopy N map shows higher canopy N values, i.e. between 1.8 and 2.2 %N, in mid-western and eastern Europe, while showing lower values, i.e. 1.2 and 1.6 %N, around the Mediterranean region and in the south of Sweden. The canopy N map obtained from the O-CN simulation shows relatively lower canopy N values, ranging from 1.0 to 1.8 %N, in central and northern Europe, while in the Mediterranean region the values are higher, between 1.8 and 2.4 %N. Similar to the RF map, the LPJ-GUESS canopy N map shows relatively higher canopy N values in mid-western Europe compared to southern and northern Europe, however, the LPJ-GUESS canopy N values show little spatial variation in the Mediterranean region. Also, the LPJ-GUESS values are higher, with canopy N values ranging between 2.0 and 2.8 %N in mid-western Europe, and canopy N values ranging between 1.6 and 1.8 %N in the Mediterranean region.
Original language | English |
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DOIs | |
Publication status | Published - 23 Mar 2020 |
Event | EGU General Assembly 2020 - Online Duration: 4 May 2020 → 8 May 2020 |
Conference
Conference | EGU General Assembly 2020 |
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Period | 4/05/20 → 8/05/20 |