TY  - JA
AU  - Dalla Tea,F.
AU  - Jokela,E.J.
TI  - Needlefall returns and resorption rates of nutrients in young intensively managed slash and loblolly pine stands
SN  - 0015-749X
U1  - 95-143663 
PY  - 1994///
KW  - Abscission
KW  - America
KW  - Elements
KW  - Forestry general aspects
KW  - Nonmetals
KW  - North America
KW  - Nutrition physiology
KW  - Physiological functions
KW  - Pinaceae
KW  - Pinus
KW  - Plant anatomy
KW  - AGROVOC
KW  - Plant physiology
KW  - Plant physiology Nutrition
KW  - Plant vegetative organs
KW  - Soil biology
KW  - South eastern states usa
KW  - Southern states usa
KW  - USA
N1  - references US (DNAL 99.8 F7632)
N2  - Annual needlefall (NF) returns and resorption rates of nutrients in 6-yr-old slash (Pinus elliottii Engelm. var. elliottii) and loblolly (P. taeda L.) pine stands were investigated using a 2 X 2 X 2 factorial experiment (species, annual fertilization, sustained competition control) in north central Florida. Compared with the reference (untreated), the combination treatment (annual fertilizer plus competition control) increased NF N returns about 6.3-fold (from 2.5 to 15.8 kg ha-1) for slash pine and 13.3-fold (from 1.5 to 19.9 kg ha-1) for loblolly pine. Similar treatment effects were found for P, with recycling rates for loblolly pine greater than for slash pine. Absolute resorption rates of N (from 4.7 to 19.9 kg ha-1 for slash pine: 2.5 to 21.1 kg ha-1 for loblolly pine) and P (from 0.5 to 1.9 kg ha-1 for slash pine; 0.2 to 2.4 kg ha-1 for loblolly pine) increased for both species as management intensity increased (i.e., cultural treatments; reference vs. fertilizer plus competition control). Howe ver, specific resorption rates of N and P were lowest for fertilizer treatments. When averaged over all cultural treatments, slash pine resorbed more N (62 vs. 57%) and P (62 vs. 51%) than loblolly pine; approximately 26% of the annual P requirements for slash pine were met by reabsorption compared with 13% for loblolly pine. Nutrient pool size within the plant (uptake) and annual nutrient demands for growth were dominant factors influencing the nature and extent of N and P resorption for both pine species
T2  - Forest science (USA). (Nov 1994). v. 40(4) p. 650-662
ER  -