Nitrogen isotope pattern in Mongolian larch stands at the southern Eurasian boreal forest boundary.

In the last decades a drastic increase in air temperature but a stable precipitation regime in Mongolia has led to gradual drying conditions. Thus, we evaluated the effect of spatial and climatic characteristics on the soil-plant nitrogen dynamics in three representative larch stands (Larix sibirica) with different geographical and climatic conditions using stable nitrogen isotopes. The results showed significant differences in the soil inorganic N content among sites and consequently a different isotopic composition in the plant-soil system.

Evaluation of the effect of the 2011 Tsunami on coastal forests by means of multiple isotopic analyses of tree-rings.

The March 2011 Mega-Tsunami in eastern Japan damaged at different degrees the black pine (Pinus thunbergii) forests along the coast. In order to evaluate the recovery of black pine four years later, tree-ring samples from 9 trees for the period 2002-2014 were analyzed for ring growth and stable isotopes (δC, δN and δO). The results showed that annual tree-ring width decreased approximately 70 % from the year 2011 to 2014 compared to the period previous to the tsunami (2002-2010).

Effects of pre-treatment on the nitrogen isotope composition of Japanese black pine (Pinus thunbergii) tree-rings as affected by high N input.

Temporal changes in the acquisition of nitrogen (N) are recorded in tree-rings together with unique N isotopic values. Some debate continues regarding the importance of wood pre-treatment in isotope analysis and, thus, this study focuses on the removal of labile components to determine the intrinsic nature of N in tree-rings. The total concentration and stable isotopic value of N in annual tree-rings were determined for two cores from Japanese black pine (Pinus thunbergii) from areas colonized by black cormorant (Phalacrocorax carbo).

Differential response of two Pinus spp. to avian nitrogen input as revealed by nitrogen isotope analysis for tree rings.

Temporal variations in N concentration and δ(15)N value of annual tree rings (1 year of time resolution) of two Japanese Black Pine (Pinus thunbergii) and three Japanese Red Pine (Pinus densiflora) trees under current breeding activity of the Great Cormorant (Pharacrocorax carbo) and the Black-tailed Gull (Larus crassirostris), respectively, in central and northeastern Japan were studied. Both species from control sites where no avian input occurs show negative values (δ(15)N = around -4 ‰ to -2 ‰) which are common among higher plants growing under high rainfall regimes. The δ(15)N values of P.