Seed release from black spruce cones in logging slash

1996 ◽  
Vol 26 (2) ◽  
pp. 266-276 ◽  
Author(s):  
R.L. Fleming ◽  
D.S. Mossa

Seed release from black spruce (Piceamariana (Mill.) BSP) cones on two clearcut sites in northwestern Ontario was evaluated over a 5-year period. Newly ripened cones were set out at seven locations on or above upland raw humus, upland mineral soil, and lowland raw humus substrates, and periodically sampled to determine the number of seeds remaining, and their germinability. Cones elevated above the substrates released 45–55% of their seeds within 1 year, and 65–75% of their seeds within 2 years. Seed release was largely confined to the growing season. Filled seeds were released more rapidly than empty seeds, and germination percent of the remaining filled seeds declined with time. Cones lying on or just above the substrates released about 25% of their seeds within 2 years, but the proportion of seeds remaining that were filled, and their germination percent, declined more rapidly with time than for elevated cones. Seed release occurred most rapidly from cones associated with upland raw humus substrates. Estimated viable seed release from cones elevated above the substrates was two to three times greater than that from cones lying on the substrates. Depending on cone location, 65–90% of all viable seed released was released within the first year after harvesting. This seed source should be considered when designing silvicultural regeneration systems for black spruce.

1994 ◽  
Vol 70 (2) ◽  
pp. 151-158 ◽  
Author(s):  
R. L. Fleming ◽  
D. S. Mossa

A series of spot seeding experiments was set out on coarse-textured upland sites in northwestern Ontario to investigate how black spruce (Picea mariana [Mill.] B.S.P.) seedling establishment and growth could be improved by site selection and seedbed preparation. Virtually all germination occurred within the first growing season. Annual seedling mortality rates were greatest during the first year, then declined steadily and stabilized at low levels (<10%) after the third year. The highest fifth-year establishment ratios (seedlings/viable seed sown) were found on seedbeds derived from materials near the mineral soil/humus interface. On wetter sites (i.e., higher Soil Moisture Regimes) the best seedbeds occurred closer to the soil surface. Mean fifth year establishment ratios for the best seedbeds were 0.032 on moderately fresh to fresh sites, 0.146 on very fresh to moderately moist sites, and 0.082 on moist to very moist sites. On adjacent lowland sites, slow-growing, compact Sphagnum mosses had a mean establishment ratio of 0.179. Mean fifth-year seedling heights on upland sites ranged from 12 to 14 cm, and were not strongly correlated with site or seedbed type. Key words: direct seeding, black spruce, seedbed, seedling establishment, site type and germination


1992 ◽  
Vol 9 (3) ◽  
pp. 107-112 ◽  
Author(s):  
Laird W. Van Damme ◽  
Lisa Buse ◽  
Steve Warrington

Abstract The effects of microsite soil compaction on direct seeding of jack pine and black spruce were tested in conjunction with Bracke scarification. The compaction effect was achieved by manually tamping the seed spot. It was anticipated that compaction might decrease the number of seeds required to establish seedlings and extend the sowing season in Northwestern Ontario Experimental results showed that compaction increased the number of scalps stocked with jack pine by 30% after the first growing season. Compaction with a pyramidal surface doubled the percent stocked scalps over conventional sowing for the latest sowing date. Compaction may allow an extension of the jack pine sowing season from late June into early July. Still, early spring sowing provided the best overall results for both species. Compaction effects were not detected for black spruce. The experimental sowing rate of five seeds per scalp may have been insufficient to detect black spruce treatment responses on the dry mineral soil seed spots. North. J. Appl. For. 9(3):107-112.


2017 ◽  
Vol 10 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Antonio DiTommaso ◽  
Lindsey R. Milbrath ◽  
Scott H. Morris ◽  
Charles L. Mohler ◽  
Jeromy Biazzo

Pale swallowwort and black swallowwort are European viny milkweeds that have become invasive in many habitats in the northeastern United States and southeastern Canada. A multiyear seedbank study was initiated in fall 2011 to assess annual emergence of seedlings and longevity of seeds of pale swallowwort and black swallowwort at four different burial depths (0, 1, 5, and 10 cm) over 4 yr. One hundred swallowwort seeds were sown in seed pans buried in individual pots, and emerged seedlings were counted and removed from May through September each year. A subset of seed pans was retrieved annually in October, and recovered seeds were counted and tested for viability. The majority of seedling emergence occurred during the first year (92% in 2012), and no new seedlings emerged in the third (2014) or fourth (2015) years. Pale swallowwort had relatively poor emergence at sowing depths of 0 cm (11%), 5 cm (6%), and 10 cm (0.05%—only one seedling), while 37% of pale swallowwort seeds emerged at 1 cm. The larger-seeded black swallowwort was more successful, with two-thirds of all sown seeds emerging at depths of 1 cm (71%) and 5 cm (66%), and 26% emerging at 10 cm. Only 16% of the surface-sown black swallowwort emerged. A large portion of the seeds that germinated at 10 cm, as well as at 5 cm for pale swallowwort, died before reaching the soil surface. Of filled seeds that were recovered in 2012 (black swallowwort at the 0-cm depth), 66% were viable. No viable seeds were recovered after the second growing season. Seeds recovered following the third year had become too deteriorated to accurately assess. Swallowwort seeds do not appear to survive more than 2 yr in the soil, at least in our experiment, suggesting that the elimination of seed production over 3 yr will exhaust the local seedbank. Seeds would need to be buried at least 10 cm for pale swallowwort but more than 10 cm for black swallowwort to prevent seedling emergence. Burial of swallowwort seeds as a management strategy may, however, only be practical in natural areas where high swallowwort densities occur.


1982 ◽  
Vol 60 (9) ◽  
pp. 1601-1605 ◽  
Author(s):  
E. Jennifer Christy ◽  
Phillip Sollins ◽  
James M. Trappe

Roots of western hemlock (Tsuga heterophylla) seedlings 1–5+ years old that had established naturally on logs in three states of decay or on mineral soil were compared for numbers and kinds of ectomycorrhizae. Mycobionts colonizing root systems included Cenococcum geophilum Fr., Piloderma croceum (Bres.) Erikss. & Hjorts., and four unidentified fungi distinguished by color and morphology. About half the seedlings surviving the first growing season (2–7 months) were nonmycorrhizal. Nonmycorrhizal seedlings were most frequent on the least decayed logs. However, mycotrophy appeared to be advantageous to hemlock; 1st-year mycorrhizal seedlings had shoots 60% longer and roots 47% longer than 1st-year nonmycorrhizal seedlings. All 2nd-year and older seedlings were mycorrhizal. The ability of western hemlock to survive the first growing season without mycorrhizae may contribute to its success in colonizing decaying logs, which may contain microsites devoid of effective ectomycorrhizal inocula.


2002 ◽  
Vol 32 (9) ◽  
pp. 1607-1615 ◽  
Author(s):  
I Charron ◽  
D F Greene

We studied the post-wildfire establishment of jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana (Mill.) BSP), and white spruce (Picea glauca (Moench) Voss) in the southern mixedwood boreal forest of Saskatchewan, Canada. The major objective of the study was to determine the influence of post-wildfire seedbed types on the juvenile survivorship of trees. Through a combination of permanent plots and sowing experiments, we demonstrated that mineral soil, thin Polytrichum Hedw. moss, and humus are much more favorable than the organic fermentation (Of) and litter seedbeds. We also show that differences among seedbeds are significantly more important than differences among species. In addition, the first year of a cohort has the highest rate of mortality, about 85% on mineral and humus seedbeds and 98% on Of seedbeds; differences in age-specific survivorship between seedbeds become muted by the end of the second year, and survivorship rates approach 1 by the end of the third summer. Finally, age structures showed that germination rates of black spruce and jack pine were very low the initial summer of the fire; that there was a peak in recruitment in the first post-fire summer; and that by the fourth year the recruitment declined to nearly zero.


Agriculture ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 67
Author(s):  
Piotr Żurawik

Crustaceans, including shrimps, are an important group of marine products processed in over 50 countries around the world. It is one of the most profitable and fast-growing processing branches. About 30 to 40% of crustaceans are used immediately after fishing, while 60–70% are processed. This generates thousands of tons of waste, proper management of which becomes increasingly important. The study was conducted in the years 2015–2017. Planting material included rhizomes of Miscanthus sinensis and Miscanthus × giganteus. Shrimp shells, dried and fragmented into 2–3 mm long pieces, were added to the soil at a dose of 5%, 10% and 15%. Mineral soil without the dried waste served as control. pH and substrate salinity were determined both before and after the growing season, and vegetative and generative traits of the plants were assessed. Shrimp biowaste is rich in N, P, K, Ca and Mg, has alkaline pH and high salinity. Its effects on plants depend on its dose and plant species. Miscanthus sinensis turned out more sensitive to the substrate salinity but in both species shrimp biowaste improved their ornamental value. For Miscanthus sinensis the most beneficial dose was 5%, while for Miscanthus × giganteus it was 15%.


2009 ◽  
Vol 89 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Dave M Morris

The current study was conducted to quantify and compare dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) fluxes through black-spruce-dominated forests, to compare the source/sink characteristics of sphagnum- versus feathermoss-dominated forest floors, and to identify changes in DOC and DON flow patterns occurring as a result of clearcut harvesting. After 2 yr of pre-harvest monitoring, replicated, experimental harvests of varying intensities of biomass removals were conducted followed by 4 yr of post-harvest sampling. Prior to harvest, the upland site type, dominated by feathermoss, was a significant source of DOC and DON, whereas, the wet-sphagnum-dominated sites exported minor amounts of these solutes. After harvest, DOC and DON fluxes peaked in the second year, but then dropped off significantly to at or below pre-harvest levels. On the upland site type, chipper debris appeared to be a major source of DOC and DON generating fluxes well above the pre-harvest levels. On the wetter site types, it appeared that microclimate differences between harvest treatments had a stronger influence on DOC and DON production than did the amount or type of harvest residue. Full-tree harvesting did not significantly alter the production of DOC and DON when compared with stem-only harvesting on the sites included in this study. Key words: DOC, DON, forest floor leachate, black spruce, harvesting response


1981 ◽  
Vol 11 (2) ◽  
pp. 259-274 ◽  
Author(s):  
Keith Van Cleve ◽  
Richard Barney ◽  
Robert Schlentner

Selected indices of structure and function were used to evaluate the effect of differing soil thermal regimes on soil-permafrost-dominated (muskeg) and permafrost-free (north-slope) black spruce ecosystems in interior Alaska. The poorly drained, permafrost site displayed cooler soil temperatures and higher soil moisture content than were encountered on the well-drained north slope. Mineral soil nutrient pools generally were largest on the permafrost site. However, low soil temperature acted as a negative feedback control, suppressing soil biological activity, nutrient mineralization, and tree primary production to lower levels on the soil-permafrost-dominated site as compared with the permafrost-free site. Forty percent larger accumulation of tree biomass and 80% greater annual tree productivity occurred on the warmer site.


1978 ◽  
Vol 54 (6) ◽  
pp. 296-297 ◽  
Author(s):  
Douglas A. Mead

Height growth of eastern larch (Larix laricina (Du Roi) K. Koch) and black spruce (Picea mariana (Mill.) B.S.P.) was determined using standard stem analysis methods on trees from two sites in northwestern Ontario. The data were obtained from mixed larch-spruce stands which were relatively undisturbed. The larch exhibited substantially better height growth than the spruce through age 65.


Author(s):  
С. І. Силенко ◽  
О. С. Силенко

Доведено, що ступінь фенотипового домінування у гібридів F1 може варіювати від hp > +1 до hp < -1 залежно від компонентів схрещування. Встановлено, що переважна більшість гібридів F1 тривалість веґетаційного періоду та його міжфазних періодів успадковують за типами позитивного наддомінування та позитивним домінуванням. Успадкування висоти рослин відбувається за типами позитивного домінування, проміжного успадкування та за типом негативного домінування. Характер успадкування висоти прикріплення нижнього ярусу бобів у значній мірі визначається поєднанням батьківських компонентів. Так, у першому поколінні у гібридних комбінаціях спостерігається явище наддомінування. За ознаками урожайності та її елементів (урожайність насіння, маса насіння з рослини, маса 1000 насінин, кількість бобів на рослині, кількість насінин із рослини, кількість насінин у бобі) у всіх без виключення гібридів першого покоління спостерігався гетерозис. It was demonstrated that the degree of phenotypic predominance in F1 hybrids can vary from hp to hp < +1 > -1 depending on mating components. The vast majority of the F1 hybrids inherit the length of the growing season and its interphase by type of over& positive dominance. F1 hybrids inherit the height of plants by types of positive dominance, intermediate inheritance and negative domination. The height of the attachment of the lower tier of the beans is largely determined by a combination of parent components. Thus, in the first generation in hybrid combinations there is the phenomenon of over dominance. Due to the yield and its components (seed yield, seed mass per plant, 1000 seeds, number of beans per plant, number of seeds per plant, number of seeds per seedpod) in all first generation hybrids heterosis is observed.


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