Crews from Cal Fire and Pacific Gas and Electric Co also are at work using chainsaws and wood chippers to remove dangerous trees. Kathryn Phillips, director of the Sierra Club California, said the die-off from drought should signal to policymakers the urgency of curbing pollution that contributes to climate change.
Trees and forests California drought Wildfires Drought news. Order by newest oldest recommendations. Show 25 25 50 All. Viable seed is disseminated from mid-October to mid-March; the percentage of viability, which ranges from 5 to 20 percent, is about equal throughout the period. Yellow-poplar is a prolific seeder, and large crops are produced almost annually 29, In North Carolina, a cm in tree produced cones with 7, sound seeds, and a cm in tree produced 3, cones with 29, sound seeds.
Measurement of the seed crop in 19 southern Appalachian stands showed an average of 3. In general, southern seeds are larger than northern ones. The individual, winged samaras may be scattered by the wind to distances equal to four or five times the height of a tree.
In southern Indiana, a seedfall pattern was shown to be oval, with the center north of the seed tree. Prevailing south and southwest winds occasionally carried seeds more than m ft. Yellow-poplar seeds retain their viability in the forest floor from 4 to 7 years Large quantities of seeds in the forest floor are capable of producing seedlings when suitable environmental conditions exist.
Seedling Development- Yellow-poplar seeds must overwinter under natural conditions, or be stratified under controlled conditions, to overcome dormancy.
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However, seedling yield increases with increasing time of stratification. Germinating yellow-poplar seedlings need a suitable seedbed and adequate moisture to survive and become established. Seed germination and seedling development is better on mineral soils or well-decomposed organic matter than on a thick, undecomposed litter layer. Scarification and fires, which put seeds in contact with mineral soil, increases the number of seedlings established significantly 10, Under normal conditions, however, the site disturbance caused by logging the mature stand is the only seedbed preparation needed to provide enough yellow-poplar seedlings for a new stand.
66 million dead trees in California could fuel 'catastrophic' wildfires, officials say
On occasional sites, deep accumulations of litter may require some seedbed treatment, particularly on the drier sites dominated by oaks or beech, and both disking and burning have proven effective. These treatments have also been recommended for sites with few seeds in the forest floor, especially if the site is covered with dense herbaceous growth. Yellow-poplar seedlings reach maximum or near-maximum photosynthetic efficiency at relatively low light intensities, as low as 3 to 10 percent of full sunlight 29, Growth was poor, however, under an overstory canopy where the amount of sunlight reaching the forest floor was limited to 1.
Sufficient sunlight can be admitted by various cutting practices. Harvest cuts ranging from removal of 30 percent of basal area to complete clearcuts have resulted in establishment and growth of large numbers of seedlings. Clearcutting, seed-tree cutting, and shelterwood cutting have all been used successfully to regenerate yellow-poplar 26,28,38, However, when partial cuts such as shelterwood are used, height growth is severely limited by the overstory.
Seedlings in clearcuts may be two to three times taller than seedlings under a shelterwood after the first 5 to 10 years. The minimum size opening that can be used to regenerate yellow-poplar is fairly small Numbers of seedlings per hectare vary little in openings of 0. Opening size, however, does affect growth significantly. Both diameter and height are retarded in openings smaller than 1. Season of logging, though not of critical importance, does have some effect on establishment and growth of yellow-poplar seedlings In West Virginia, Ohio, and Indiana, summer logging produced fewer seedlings than logging at other times of the year.
Apparently, in summer-logged stands most of the seeds did not germinate until the following year, and these small seedlings were not as well able to compete with the rank vegetation that started the previous year. Nevertheless, cuttings in summer months usually have produced sufficient seedlings where a good seed source previously was present. If seed supply is expected to be scarce, logging in fall, winter, or early spring might be advisable.
After germination, several critical years follow. During this period sufficient soil moisture must be available, good drainage and protection against drying and frost heaving are necessary, and there must be no severe competition from nearby sprout growth. In a study in which various mulches were used to induce soil temperature variation, seedlings grew faster in warm soil than in cool soil.
Soil temperatures as high as Yellow-poplar seedlings normally survive dormant-season flooding, but it was found that 1-year-old seedlings were usually killed by 4 days or more of flooding during the growing season This vulnerability during the growing season explains why yellow-poplar does not grow on flood plains of rivers that flood periodically for several days at a time. After the first growing season, vegetative competition may become the most important factor affecting survival and growth. Reducing competition by cutting, burning, disking, or by using herbicides may be needed to assure success.
On favorable sites the success of regeneration can usually be determined by the size and vigor of the seedlings at the end of the third year. Height growth during the first year ranges from a few centimeters to more than 0. With full light, rapid height growth begins the second year, and at the end of 5 years trees may be 3 to 5. During its seedling and sapling stages, yellow-poplar is capable of making extremely rapid growth.
An year-old natural seedling The behavior and duration of height growth of yellow-poplar vary by latitude. In a Pennsylvania study, seedlings had a day height-growth period beginning late in April and ending about August 1. A sharp peak in height growth was reached about June 1. In a northwestern Connecticut study, yellow-poplar had a day height-growth period beginning in late April and ending in mid-August. Ninety percent of this growth took place in a day period from May 20 to July 20, and a sharp peak in height growth was noted in the middle of June. In a study conducted in the lower Piedmont of North Carolina, yellow-poplar had a day height-growth period beginning in early April and ending about the middle of September.
Growth was fairly constant, and there was no peak in growth rate during the growing season. Vegetative Reproduction- Yellow-poplar sprouts arise chiefly from preexisting dormant buds situated near the base of dead or dying stems, or near the soil line on stumps. Sprouts may occur as high as 30 to 38 cm 12 to 15 in on high stumps, but more than 80 percent arise at or below the soil line The percentage of stumps sprouting and the number of sprouts per stump decrease with increasing stump size.
Stumps as large as 66 to 76 cm 26 to 30 in sprouted 40 percent of the time, however, with an average of eight sprouts per stump. Yellow-poplar of the age and size harvested in second-growth stands sprouts prolifically. Trees of sprout origin are more subject to butt rot than those of seedling origin Nevertheless, a high percentage of stumps that sprout produce at least one stem that is well anchored, vigorous, and of desirable quality for crop-tree development In this respect, position on stump is important to subsequent development.
Sprouts arising from roots or from the stump below groundline usually lack a heartwood connection with the stump heartwood because the roots and below-ground portions of the stump do not normally contain heartwood. Sapwood tissues separating heartwood columns of stumps and sprouts may prevent heart rot fungi, which enters the stump heartwood, from spreading to the heartwood of the sprout.
The initial growth rate of yellow-poplar sprouts far exceeds that of young seedlings. In western North Carolina, the dominant sprout on each of 60 stumps on a good site grew an average of 1. At age 24, these sprouts averaged In West Virginia, the dominant stem of each sprout clump grew at the rate of 0. The rapid, early growth rate begins to drop off rnarkedly somewhere between 20 and 30 years.
At this time, seedlings of similar age may catch up and exceed sprouts in rate of height growth. A number of investigators have attempted to root yellow-poplar cuttings, but most early attempts were not successful. In a more recent study, cuttings were rooted successfully after they were dipped in dolebutyric acid and a mist of water was sprayed over the propagation bed 6.
It is not known, however, whether these rooted cuttings would have successfully survived outplanting. Yellow-poplar has been successfully rooted from stump sprouts of 7-year-old trees; soft-tissue cuttings placed in a mist bed began rooting in 4 weeks and successfully survived transplanting. A system of splitting seedlings longitudinally and then propagating the halves was also highly successful.
However, splitting seedlings provides only one additional new plant from the ortet, while rooting stump sprouts provides several. A technique for propagating yellow-poplar by making use of its epicormic branching ability has recently been described Partial girdling into the outer one or two annual rings results in a profusion of epicormic sprouts that can then be rooted in the same way as stump sprouts.
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This method has the advantage of preserving the selected ortet for repeated use. Experience with this method, however, reveals that not every girdled tree will sprout well. Young trees and trees with low vigor are better sprouters than old trees and rapidly growing trees. Growth and Yield- The mature yellow-poplar has a striking appearance. In forest stands its trunk is very straight, tall, and clear of lateral branches for a considerable height. It is among the tallest of all Eastern United States broadleaf trees.
On the best sites, old-growth trees may be nearly 61 in ft high and 2. Age at natural death is usually about to years. However, some trees may live up to years. These data represent an average dominant tree grown under fully stocked stand conditions. The largest trees would be 7. Table 2 shows selected empirical yields for natural stands 3, Mean annual increment in total cubic volume ranges from 5. Rooting Habit- Yellow-poplar has a rapidly growing and deeply penetrating juvenile taproot, as well as many strongly developed and wide-spreading lateral roots.
It is considered to have a "flexible" rooting habit, even in the juvenile stage. Reaction to Competition- Although classed as intolerant of shade, yellow-poplar can overcome much competition because it produces numerous seedlings and sprouts, and grows very rapidly. On land of site index 23 m 75 ft and higher in the southern Appalachians, yellow-poplar has faster height growth than any of its associates except white pine up to 50 years of age If not overtopped, yellow-poplar takes and holds its place in the dominant crown canopy of the developing stand.
It is often a pioneer on abandoned old fields or clearcut land and may form essentially pure stands on very good sites. More often it regenerates as a mixed type with other species, and it commonly persists in old-growth stands as scattered individuals. Yellow-poplar expresses dominance well and seldom, if ever, stagnates because of excessive stand density. It prunes very well in closed stands. Although it produces epicormic sprouts when the bole is exposed, this trait is less pronounced than in many other hardwood species.
Because of these growth characteristics, yellow-poplar stands can develop and produce considerable quantities of large, high-quality products with no intermediate stand management.
66 million dead trees in California could fuel 'catastrophic' wildfires, officials say
In the seedling-sapling stage, dominant and codominant trees are little affected by thinning or cleaning 21, Intermediate or overtopped trees of good vigor respond to release in both diameter and height growth Officials flying over the region captured images of dead patches that have turned a rust-colored red.
California is in the fifth year of a historic drought , which officials say has deprived trees of water, making them more vulnerable to attack from beetles. Governor Jerry Brown in October declared an emergency, forming a taskforce charged with finding ways to remove the trees that threaten motorists and mountain communities. These efforts have hit obstacles, slowing the tree removal as California enters a potentially explosive wildfire season. Brown pushed for burning the trees at biomass plants to generate electricity, sending them to lumber mills or burning them in large incinerators, removing potential fuel for wildfires.
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