Measured <i>δ</i>¹⁵N <i>vs</i>. predicted <i>δ</i>¹⁵N for fossil plants using fossil bone <i>δ</i>¹⁵N and modern <i>Δ</i>¹⁵N_{Col-Bulk plant} = 1.9 ‰.

<p>Measured <i>δ</i>¹⁵N <i>vs</i>. predicted <i>δ</i>¹⁵N for fossil plants using fossil bone <i>δ</i>¹⁵N and modern <i>Δ</i>¹⁵N_{Col-Bulk plant} = 1.9 ‰.</p

C and N contents and isotopic compositions for fossil plants.

<p>C and N contents and isotopic compositions for fossil plants.</p

Repeated measure ANOVA test results for time effects on <i>δ</i>¹³C_litter and <i>δ</i>¹⁵N_litter.

<p>Repeated measure ANOVA test results for time effects on <i>δ</i>¹³C_litter and <i>δ</i>¹⁵N_litter.</p

Sample locations.

<p>GC = Glacier Creek; LB = Little Blanche Creek. Adapted after Kotler and Burn [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0192713#pone.0192713.ref077" target="_blank">77</a>].</p

Nitrogen isotopes suggest a change in nitrogen dynamics between the Late Pleistocene and modern time in Yukon, Canada - Fig 12

<p><b>SEM images of plant macrofossils:</b> (a, b) typical decomposed surface of fossil stems, and (c, d) fungal hypha (yellow arrows) and bacteria cells (red arrows) on fossil stem surfaces.</p

Typical plant macrofossils recovered from fossil nests.

<p>(a) <i>Deschampsia cespitose</i> floret; (b) <i>Deschampsia cespitosa</i> floret with stem; (c) <i>Carex albonigra</i> floret and seed; (d) <i>Alopecurus</i> sp. floret; (e) <i>Draba</i> sp. Silique; (f) <i>Ranunculus eschscholtzii-sulphureus</i> type achene.</p

Nitrogen isotopes suggest a change in nitrogen dynamics between the Late Pleistocene and modern time in Yukon, Canada - Fig 5

<p>Values of <i>δ</i>¹⁵N_litter <i>vs</i>. time during decomposition: (a) ‘buried’ and (b) ‘not buried’.</p

Average N <i>vs</i>. C contents of fossil and modern plants.

<p>Average N <i>vs</i>. C contents of fossil and modern plants.</p

Typical plant macrofossils recovered from fossil nests.

<p>(a) <i>Carex</i> floret; (b) <i>Campylium stellatum</i> stem with leaves; (c) <i>Conioselinum cnidii folium</i> carpel; (d) <i>Asteracea</i> achenese, pappus; (e) <i>Lepidium densiflorum</i>; (f) <i>Phlox hoodii</i> capsule; (g) <i>Taraxacum ceratophorum</i> achene; (h) <i>Pedicularis</i> sp. achene; (i) <i>Silene</i> cf. <i>taymirensis</i> capsule with seeds inside; (j) <i>Polemonium</i> capsule; (k) <i>Ranunculuc pensylvanicus-macounii</i> type achene; (l) <i>Plantago</i> cf. <i>canescens</i> capsule.</p

Values of <i>δ</i>¹⁵N <i>vs</i>. <i>δ</i>¹³C of plant macrofossils after correction for the isotopic effects of decomposition (squares).

<p>The mean (filled circle) and range (whiskers) of <i>δ</i>¹⁵N and <i>δ</i>¹³C for modern plants from the region [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0192713#pone.0192713.ref009" target="_blank">9</a>] are shown in black.</p