摘要:

Water storage by the forest floor and its relation to other characteristics of the forest floor were determined for three forest types (spruce-fir (Piceaspp. -Abiesspp.) partially, cut spruce-fir, and young lodgepole pine (PinuscontortaDougl.), and three predominant aspects (north, south, and east) on Marmot Creek experimental watershed in south western Alberta.There was no significant difference between uncut and partially-cut spruce-fir forest floor in water-storage capacity, depth of water held after draining, water held per unit thickness of forest floor, or dry weight, although forest-floor thickness was greater under uncut spruce-fir (11.36 cm) than partially cut (9.84 cm). The forest floor averaged for cut and uncut spruce-fir had greater water-storage capacity (1.93) than under young lodgepole pine(1.35), greater depth of water held (1.94 cm, 0.85 cm,) greater dry weight (89 506 kg/ha, 55 039 kg/ha), and greater thickness (10.60 cm, 4.59 cm). There was no difference in water held per unit thickness of forest floor (0.19 cm/cm under spruce-fir, 0.18 cm/cm under pine). The lower values for pine than for spruce-fir are attributed to an intense fire 30 years ago on the area presently supporting the young pine.Regressions are given of water held on forest-floor thickness, weight of water held on dry weight, and water-storage capacity on thickness.

ISSN:0045-5067    

DOI:10.1139/x72-001

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The rate and percent of dark germination were low in untreatedPinustaedaL. seeds. Both increased with seedcoat clipping or removal, but not to the level of stratified seeds. Coats did not reduce the rate of initial water inhibition but did limit total uptake prior to germination, probably by restricting swelling of the megagametophyte and embryo. Respiration followed the pattern of water absorption in decoated seeds. However, it was at a common low level in stratified, clipped, and unstratified seeds until germination began, and there seemed to be no causal relation between respiration and coat permeability. Dormancy is likely to be the result of mechanical constraint by the seedcoat.

ISSN:0045-5067    

DOI:10.1139/x72-002

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Wood discs cut from 23-year-old lodgepole pine (PinuscontortaDougl. var.lalifoliaEngelm.) stems were analyzed for vertical and radial resin duct densities adjacent to basal injuries caused by the weevil,HylobiuswarreniWood. The injury from single attacks continued for at least 2 years and was characterized by reduced radial growth and an abundance of vertical 'traumatic' resin ducts above the wounds. No increase in radial duct density was detected above the wounds.

ISSN:0045-5067    

DOI:10.1139/x72-003

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

A study into the distribution of thermophilic and thermotolerant fungi in a spruce-pine (Piceaspp.—Pinusspp.) wood chip pile at Prince George, B.C., was carried out. Five treatments were examined: pine, spruce, spruce containing a core bag of fines, spruce containing a core bag of sterilized spruce chips and spruce containing a core bag of spruce chips inoculated with aPtychogastersp. [probablyChrysosporiumpruinosum(Gilman and Abbott) Carmichael]. Samples of wood chips buried at different locations in the chip pile were examined after 3, 6, and 12 month storage periods. From 100 randomly selected chips from each sample, the fungi were isolated on 2% malt, 2% agar, and 0.5% malic acid medium. Data on temperature during storage, pH of wood chips, moisture content, and weight loss at the time of sampling were calculated for the various sampling positions.Thermophilic fungi colonized the inner regions of the wood chip pile where higher wood substance losses occurred, while thermotolerant fungi inhabited the outer regions. Among the thermophilic fungi listed according to frequency of isolation wereByssochlamysemersoniiStolk-Apinis,AllescheriaterrestrisApinis,SporotrichumthermophileApinis,ThermoascusaurantiacusMiehe, andHumicolalanuginosa(Griffon and Maublanc) Bunce. The most common thermotolerant fungi wereAspergillusfumigatusFresenius andC.pruinosum.Fungal distribution was generally related to position in the wood chip pile. Of the associated factors, temperature (17–60 °C) was most strongly related to fungal distribution, whereas treatment, pH of wood chips, and moisture content did not relate to fungal distribution.

ISSN:0045-5067    

DOI:10.1139/x72-004

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Above-ground biomass, annual production, and leaf area index (LAI) were estimated for several years in aspen stands aged 6, 15, and 52 years old in 1968. Based on regressions of dry weight on stem diameter, biomass (stems and branches) estimates for 1968 were 21 500 kg ha−1in the juvenile stand, 51 200 kg ha−1in the intermediate stand, and 91 800 kg ha−1in the mature stand. Net annual above-ground production (stems and branches) for these stands in 1968 was 6900, 7000, and 1340 kg ha−1respectively. In 1969, foliage amounted to 2600, 2600, and 1500 kg ha−1, providing LAI of 2.4, 2.9, and 1.6 for the stands. Net assimilation rates were roughly 20, 17, and 9 g m−2week−1.Aspen stands regenerated as suckers may attain maximum annual production within a few years, coincident with the development of maximum LAI.

ISSN:0045-5067    

DOI:10.1139/x72-005

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Data are presented on the consumption of duff by fire on six plots in a jack pine (PinusbanksianaL.) stand and six plots in a red and white pine (P.resinosaAit andP.strobusL.) stand. The amount consumed was found to correlate well with the moisture content of the duff before fire, and with the Duff Moisture Code, a component of the Canadian Forest Weather Index. A tentative theory to account for the amount of duff consumed is presented in terms of (a) downward heat transfer within the flaming front, and (b) the energy required to heat the duff to ignition temperature.

ISSN:0045-5067    

DOI:10.1139/x72-006

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The assumption of randomness, underlying the use of range as an estimator of the standard deviation in a normal parent population, was deliberately violated in order to assess how restrictive is this assumption in sampling tree diameters and heights. In only four, out of 34 non-random samples, were the estimates of population standard deviation using range significantly lower than the corresponding root-mean-square estimates. These underestimates were reduced by randomizing the collected data.

ISSN:0045-5067    

DOI:10.1139/x72-007

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Cost data obtained from a 1969 inventory of a 5600 acre (2268 ha) forest are presented and analyzed. A seperation of the data into fixed and variable costs is made. The effect on cost of specifications regarding precision and detail of information is explored.

ISSN:0045-5067    

DOI:10.1139/x72-008

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The basic assumptions of regression analysis are recalled with special reference to the use of a logarithmic transformation. The limitations imposed on inference-making by failure to comply with these assumptions are discussed and ways to avoid the limitations indicated. A systematic bias of the order of 10 to 20% which is inherent in most, if not all, prior uses of the logarithmic equation to estimate plant biomass is noted as is the correction for the bias.

ISSN:0045-5067    

DOI:10.1139/x72-009

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The resistance to a pulsed electric current decreased sharply as the tips of stainless steel electrodes entered discolored and decayed tissues in living deciduous trees. The apparatus delivering the pulsed electric current is described.

ISSN:0045-5067    

DOI:10.1139/x72-010

出版商:NRC Research Press    

年代:1972

数据来源: NRC