Cone Production and Seedfall in a Mature White Spruce Stand

Waldron, R. M.

doi:10.5558/tfc41316-3

Cited by 30 publications

(16 citation statements)

References 1 publication

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“…A total of 335 datasets were collated from various sources (Waldron 1965, Alexander et al 1982, Hickey et al 1983, Graber and Leak 1992, Pucek et al 1993, Kelly 1994, Fitzgerald et al 1996, Herrera et al 1998, Wilson et al 1998, Hickey and Wilkinson 1999 of which only those of 6 yr or longer were used (n=210). CVs from Herrera et al 1998 were based on SD(n− 1) and so were corrected to SD(n) for consistency.…”

Section: Degree Of Masting and Synchronymentioning

confidence: 99%

Predator satiation and extreme mast seeding in 11 species of Chionochloa (Poaceae)

Kelly¹,

Harrison²,

Lee³

et al. 2000

Oikos

126

120

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Variation in annual flowering effort is described for 16 long datasets from 11 species of Chionochloa (Poaceae) in New Zealand. All populations exhibited extreme mast seeding. The most variable species was C. crassiuscula (coefficient of variation, CV= 3.02) over 26 years at Takahe Valley, Fiordland, which is the highest published CV we know of worldwide. The other populations also had high CVs (lowest CV= 1.42, mean CV = 1.84) which were higher than for other well-studied genera such as Picea, Pinus and Quercus. There were also frequent years of zero flowering (mean across all populations was 37.2% zero years; maximum 53% for C. rubra and C. crassiuscula over 19 years) whereas zero years are rare in other published masting datasets. Flowering was highly synchronous among species within a site (mean r= 0.886), and also (though significantly less so) among sites. Among sites, synchrony was not significantly higher within-species (mean r =0.711) than between-species (r= 0.690). Warm summer temperatures led to heavy flowering the following summer. Flowering synchrony increased with increasing synchrony in local deseasonalised summer temperatures, and decreased with increasing distance between sites. Mast seeding has been shown in Chionochloa to reduce losses to specialist flower or seed predators. Among-species synchrony may be adaptive if species share a common seed predator. Developing seeds of at least 10 Chionochloa species are attacked by larvae of an undescribed cecidomyiid. In Takahe Valley, where masting is most pronounced, cecidomyiids attacked all six Chionochloa species in all four years studied. Mean annual losses were almost constant (10.0 to 13.4%) while flowering effort varied 100-fold. The invariant losses are consistent with other evidence that the cecidomyiid may have extended diapause, which would make it harder to satiate by mast seeding. We hypothesise that one possible factor favouring such extremely high levels of mast seeding in Chionochloa is that its seed predator is very hard to satiate. Kelly and A. L. Harrison, Plant and Microbial Sciences, Uni6. of Canterbury, Christchurch 1, New Zealand (d.kelly@botn.canterbury.ac.nz). -W. G. Lee, Landcare Research, Pri6ate Bag 1930, Dunedin, New Zealand. -I. J. Payton, Landcare Research, P.O. Box 69, Lincoln, New Zealand. -P. R. Wilson, Landcare Research, Pri6ate Bag 6, Nelson, New Zealand. -E. M. Schauber, Dept of Ecology and E6olutionary Biology, Uni6. of Connecticut, Storrs, CT, USA and Inst. of Ecosystem Studies, Millbrook, NY, USA. Mast seeding is the intermittent synchronous production of large seed crops by a population of plants (Kelly 1994). It requires variation among years in the reproductive effort of individual plants and synchrony between individuals within a population. Mast seeding is found in plants from many different taxonomic groups and from most parts of the world, although it seems to be especially common in temperate forest trees (Silvertown 1980) and in the New Zealand flora (Webb and Kelly 1993, Kelly 1994). From an...

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Section: Degree Of Masting and Synchronymentioning

confidence: 99%

Predator satiation and extreme mast seeding in 11 species of Chionochloa (Poaceae)

Kelly¹,

Harrison²,

Lee³

et al. 2000

Oikos

126

120

View full text Add to dashboard Cite

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“…White spruce regeneration and juvenile growth are highly variable, and are impeded by factors such as competition, site quality, low soil temperature, climate, and seed predation. Natural regeneration of white spruce is often inadequate to meet reforestation standards due to its sporadic seed production cycle, the lack of persistence of seeds in soil, and inadequate seedbed or microsite conditions [38,40,42,43]. Even when white spruce does regenerate successfully, overstocking and other competition can result in slow growth rates; after 27 years, naturally regenerated white spruce on an interior Alaska site measured less than 4 m in height [40].…”

Section: Introductionmentioning

confidence: 99%

Effects of competing vegetation on juvenile white spruce (Picea glauca (Moench) Voss) growth in Alaska

2003

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-We examined the impacts of competing vegetation on survival and juvenile growth of white spruce (Picea glauca (Moench) Voss) on 3 units in south-central Alaska and on 3 units in interior Alaska. Treatments consisted of herbicide site preparation and release treatments, and also included a treatment in which competition was minimized for 5 years (weed-free treatment). At all units, the weed-free treatment resulted in significant increases in white spruce height and basal diameter by ages 10 or 11 compared to untreated plots. Average heights and diameters in the weed-free treatments were 1.5 to 3.8 times and 2.0 to 3.8 times those in the untreated plots, respectively. Results from the other treatments differed by unit based on the efficacy of a particular treatment on the vegetation at that unit. For all units, regression equations indicated a significant decrease in diameter at year 10 or 11 with increasing competitive cover and overtopping.

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“…In a later report (1955) he suggests that squirrels take most of the spruce cones and seed except in heavy seed years. Waldron (1965) from a study of seedfall under a mature white spruce stand in Manitoba reports a count of 52,000 white spruce seeds per acre on top of the snow in February of 1960.…”

Section: Discussionmentioning

confidence: 99%

Winter Scarification and White Spruce Regeneration, Saskatchewan

Gilmour¹

1966

The Forestry Chronicle

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During the frost free period in Saskatchewan, access to many forest areas is restricted, and the movement of heavy machinery in the forest is limited. Because of this, an experiment to test the effectiveness o f winter seedbed disturbance was established on a 2-chain cut strip. Adequate natural restocking to white spruce was recorded on winter disturbed seedbeds the following summer. A link between a lengthy period o f seed dissemination and a heavy cone crop seems evident from the results. This feature, coupled with a winter seedbed disturbance, may prove ziseful to assisted spruce regeneration in this province. Regeneration resulting from the residual trees obscured the results o f artificially sown white spruce. However, the results show the effect o f different sowing rates and indicate that spring sowing produces more seedlings.The restoration of native conifers, particularly the spruces, in Boreal Saskatchewan is a diverse problem.White spruce (P. glauca (Moench) Voss) is co-existent with the shorter-lived aspen in "the characteristic forest association of the well drained uplands" in Saskatchewan (Rowe 1959). Logged-over spruce lands are heavy to aspen (P. tremuloides Michx.) with a frequent white birch admixture ( B . papyrifera Marsh.). Balsam f i r V A . balsamea (L.) Mill.) is often present when this species forms an understory to white spruce.No certain silvicultural prescription has as yet evolved for spruce producing areas in the province, but Hurd (1965) sets forth a useful guideline for "uncertain foresters". Our job, he writes, is "to grow timber best adapted to (his) particular soils and to produce the best quality forest at the least expense." Tree association classifications of nature provide the gudeline as to what species to grow (and even how to grow them) but the "least expense" require ment is not always met when trying to maintain the premium species.The effort to maintain white spruce is well founded. Winter scarification For personal use only. 168FORESTRY CHRONICLE at present is one hopeful means of approaching this goal, keeping the "least expense" requirement to the fore. The physical limitations to area accessibility involved in summer scarification, along with the fact that the timber operator with his men and machines is established in a cutting area during the winter, prompted the present experiment.In 1959 alternate strip-cutting and summer scarscation was initiated in our white spruce-aspen stands by the Saskatchewan and Federal departments of forestry. Early results in terms of numbers of white spruce seedlings and their survival have been good (Jarvis 1963). Winter scarification in alternately stripcut lowland black spruce was initiated in 1963 and in upland white spruce in 1964, by the Saskatchewan forestry branch.An analysis of data from four meteorological stations on the southern edge of the mixedwood zone in Saskatchewan by Kagis (1962) indicated that Thornthwaite's climatic type varies from one year to another from a moist subhumid (C2), to dry subhumid (C,) ,...

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Cone Production and Seedfall in a Mature White Spruce Stand

Cited by 30 publications

References 1 publication

Predator satiation and extreme mast seeding in 11 species of Chionochloa (Poaceae)

Predator satiation and extreme mast seeding in 11 species of Chionochloa (Poaceae)

Effects of competing vegetation on juvenile white spruce (Picea glauca (Moench) Voss) growth in Alaska

Winter Scarification and White Spruce Regeneration, Saskatchewan

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