Effects of acid mist on mature grafts of Sitka spruce. Part I. Frost hardiness and foliar nutrient concentrations

1994 ◽  
Vol 85 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Lucy J. Sheppard ◽  
I.D. Leith ◽  
J.N. Cape
1993 ◽  
Vol 23 (4) ◽  
pp. 743-748 ◽  
Author(s):  
André J. Hudson

The natural invasion of mountain alder (Alnuscrispa (Ait.) Pursh) into monoculture plantations of black spruce (Piceamariana (Mill.) B.S.P.) and Sitka spruce (Piceasitchensis (Bong.) Carr.) afforded an opportunity to assess the effects of mountain alder on soils, and on the growth, nutrient status, and survival of spruce in eastern Newfoundland. The plantations were established on ploughed Kalmia–Vaccinium heath in 1968–1969. Significant increases in the growth of spruce were associated with the presence of high densities of mountain alder in the two plantations studied. The increases began 3–6 years after the invasion and establishment of mountain alder. Estimated nitrogen (N) contributions to each plantation from mountain alder leaf litter fall were approximately 50 kg•ha−1•year−1. Spruce foliage N content was 10–15% higher in high-density mountain alder (HD-alder) plots than in low-density mountain alder (LD-alder) plots, but other foliar nutrient concentrations were low and possibly deficient in the HD-alder plots. Development of a litter fall–humus layer was observed in HD-alder plots but not in LD-alder plots; however, B-horizon soil-N values did not differ significantly between HD-alder and LD-alder plots. The mountain alder invasion did not reduce the densities (stems/ha) of spruce. Additional studies on the autecology of Alnus spp. native to Newfoundland, and on alder-spruce interaction are recommended to further the development of an adequate ecological basis for heathland and peatland afforestation in the region.


1995 ◽  
Vol 25 (1) ◽  
pp. 18-28 ◽  
Author(s):  
B.J. Hawkins ◽  
M. Davradou ◽  
D. Pier ◽  
R. Shortt

One-year-old seedlings of western red cedar (Thujapiicata Donn ex D.Don) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were grown for one season in five nutrient treatments with nitrogen (N) supplied in solution at rates of 20, 100, or 250 mg•L−1 and phosphorus (P) supplied at rates of 4, 20, or 60 mg•L−1. Growth, onset of dormancy, frost hardiness on six dates, and foliar nutrient concentrations in autumn and spring were measured. Midwinter rates of net photosynthesis and transpiration were measured at air temperatures of 4, 7, and 11 °C in seedlings from all nutrient treatments. Recovery of net photosynthesis and transpiration in whole seedlings from the three N treatments was assessed at intervals for 28 days after the seedlings were frozen to −5, −15, and −25°C. Foliar N content differed significantly among nutrient treatments and was positively correlated with supply. Mitotic activity ceased earliest in plants with low N supply. Douglas-fir seedlings in the low-N treatment also ceased height growth earliest. These differences in growth had no significant correlation with frost hardiness. No consistent differences in frost hardiness among nutrient treatments were observed. Higher rates of N and P supply resulted in higher rates of winter net photosynthesis. Net photosynthesis was reduced dramatically by night frost, with greater damage occurring at lower temperatures. Net photosynthesis recovery occurred most quickly in seedlings with the midrate of N and P supply.


1996 ◽  
Vol 23 (2) ◽  
pp. 185 ◽  
Author(s):  
SA Munks ◽  
R Corkrey ◽  
WJ Foley

The distribution of the koala (Phascolarctos cinereus) and the common brushtail possum (Trichosurus vulpecula) within the Prairie-Torrens Creek Alluvials province of the Desert Upland region of north-western Queensland was examined. The optimum habitat for each species as indicated by the occurrence of faecal pellet groups was found to be that associated with creek-lines. However, other land types were also used by each species to varying degrees. The relationship between various habitat variables and pellet group counts was investigated using Multiple regression and a Generalised linear model. Proximity to creek-bed, total basal area of trees, species richness and Acacia basal area (negative) best explained the occurrence of koalas. Proximity to creek-bed, Acacia basal area (negative), total basal area of trees, and available water (negative) best explained the occurrence of brushtail possums. In contrast to studies of arboreal species in the moist-south-eastern forests of Australia no relationship was found between foliar nutrient concentrations and the occurrence of koalas or brushtail possums. However, a significant relationship was found between leaf water concentration and the occurrence of koalas. It is suggested that water availability is the paramount factor defining preferred arboreal habitat in arid and semi-arid woodlands.


2013 ◽  
Vol 59 (No. 8) ◽  
pp. 306-318 ◽  
Author(s):  
I. Kuneš ◽  
M. Baláš ◽  
V. Balcar ◽  
D. Kacálek ◽  
K. Millerová ◽  
...  

We evaluated the potential of crushed amphibolite and artificial slow-release N-P-K-Mg fertiliser to stimulate the survival, growth and nutrition of Norway spruce planted on an acidified air-polluted mountain site. Control plots and treatments with slow-release fertiliser (SRF) and amphibolite (AMT) were installed. In the SRF, forty grams of tabletted amendment were applied in the close vicinity of the trees. In the AMT, two kilograms of amendment were incorporated into the soil inside the planting hole of each tree at planting. The SRF application resulted in a significant growth stimulation of spruces. The growth stimulation by amphibolite was perceptible but not significant; this amendment, however, significantly reduced mortality. None of the amendments induced marked changes in foliar nutrient concentrations.  


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