Table 1 Extent of yearly values for litterfall (needles, leaves, and spruce budworm frass) carbon and nutrients fluxes (kg ha−1 yr−1) during a spruce budworm outbreak in northeastern Canada.

From: Defoliation-induced changes in foliage quality may trigger broad-scale insect outbreaks

Stand type

Carbon

Nitrogen

Phosphorus

Potassium

 

Min

Max

Ratio

Min

Max

Ratio

Min

Max

Ratio

Min

Max

Ratio

Bf-standa

359

1274

3.6

6.2

34.0

5.5

0.7

3.4

4.9

0.8

2.2

2.8

Bs-standb

337

890

2.6

3.2

12.9

4.0

0.3

1.6

5.3

0.4

0.9

2.3

Mixedc

410

960

2.3

5.1

22.9

4.5

0.5

2.1

4.2

0.5

1.5

3.0

  1. Bs: Black spruce-dominated stands, where basal area (m2 ha−1) of black spruce represents > 75% of total coniferous tree basal area in the stand‡.Mixed stands, where balsam fir and black spruce each represent between 25% and 75% of total coniferous basal area.
  2. aMinimum values occurred in 2011 or 2012 and maximum values at defoliation peaks (2014 or 2017).
  3. bBf: Balsam fir-dominated stands, where basal area (m2 ha−1) of balsam fir represents > 75% of total coniferous tree basal area in the stand.
  4. cBs: Black spruce-dominated stands, where basal area (m2 ha−1) of black spruce represents > 75% of total coniferous tree basal area in the stand.
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