Following a uniform thinning, a young bigtooth aspen (Populusgrandidentata Michx.), quaking aspen (Populustremuloides Michx.), paper birch (Betulapapyrifera Marsh.), and red maple (Acerrubrum L.) stand was treated with nitrogen (N), phosphorus (P), and lime, singly and combined. Nitrogen increased the growth of all species. Lime and P also tended to increase the growth of bigtooth aspen and paper birch. Nitrogen increased mortality and lime reduced mortality. Quaking aspen suffered proportionally greater mortality than other species. The results suggest that both N and lime will be required for an optimum response of aspen and birch growing on acid spodosols in the Northeast, but the cause of and a means to avoid increased mortality caused by fertilizer needs to be determined before large-scale N fertilizer treatments are adopted.
Eighteen columns of discolored and decayed wood associated with 2-year-old artificial wounds, and adjacent clear wood in three red maple trees, Acerrubrum L., plus six columns of clear wood in two nonwounded trees were mapped systematically for concentrations of K, Mn, Ca, Mg, and Na. Concentrations of the elements in discolored and decayed wood were higher than in adjacent clear wood in the same tree and in clear wood in the nonwounded trees. Concentration of K was highest in discolored and decayed wood near the wound and the concentration decreased toward the ends of the columns. Concentration of Mg was similar to K but the decrease in concentration toward the ends of the columns was more gradual. Concentrations of Mn and Ca were greatest at points between the wound and the ends of the columns. The different patterns of distribution between K and Mg, and Ca and Mn suggest that these elements may have different roles in the discoloration and decay process.
SUMMARYEstimates were made of the above-ground biomass and contents of N, P, K, Ca, Mg, Mn, Na, Fe, Zn, A1, and Cu in fertilized (N 448 kg/ha, P 112 kg/ha, lime 4480 kg/ha) and unfertilized white birch (Betula papyrifera Marsh,) and bigtooth aspen (Populus grandidentata Michx.). For individuals of both species, fertilization increased the average above-ground biomass increment and the N and P content increment by 150 per cent and 300 per cent, respectively, but decreased uptake of Mn and Zn. The allocation of biomass and elements differs not only between species, but within species under untreated and fertilized conditions.
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