Treesearch

The behavior of white pine blister rust at Mountain Home State Demonstration Forest and surrounding areas in the southern Sierra Nevada of California indicates that the epidemic has not yet stabilized and that the most likely prognosis is a pandemic on white pines in this region within the next few decades. The impact on sugar pines, from young regeneration to old growth, already has been severe in some areas, and silvicultural control measures have been largely ineffective. An operational genetic program, based on selection of seed parents carrying a major resistance gene, is described...

The wood of lodgepole pines and whitebark pines from a high elevation site in the east central Sierra Nevada of California was analyzed for chemical content to determine whether there were any temporal patterns of chemical distribution in tree rings. Cores were taken from 10 trees of each species and divided into 5-year increments for chemical analysis. Correlation analysis indicated that calcium and magnesium, both of which have divalent cations, were strongly correlated for both species. The elements copper, iron, cobalt, nickel, molybdenum, chromium, tin, and arsenic were all significant...

Forty-nine species of mammals regularly occur in California chaparral, but none lives only in chaparral. Among the 49 species, 7 are found primarily in mature chaparral, 9 in young chaparral or along ecotones between chaparral and other plant communities, and 19 in riparian areas. Five species occur in many habitats but prefer chaparral in California,and 9 have wide ranges that encompass many communities including chaparral. By altering the structure of the plant community, fire in chaparral is important in determining the distribution and abundance of mammalian populations. Fire is not...

Minerotrophic peatlands or fens in California's Sierra Nevada are small wet meadows surrounded by mixed conifer forest. The dynamics of vegetation change at the meadow edge and the ages and development of fens were investigated, in the Sagehen Creek Basin near Truckee, California, through the use of radiocarbon dating of peat, pollen studies, examination of processes of peat development and accumulation, stand age analysis of trees around peatlands, and evaluation of tree-ring variation. These approaches were used to evaluate both short- and long-term changes. Fens varied in age from more...

Studies stimulated by the International Biological Program showed total insect faunal biomass and diversity to be greatest in the spring of the year, which matches increased plant growth and flowering at this time. Ground-inhabiting beetle studies indicated the family Tenebrionidae to be overwhelmingly dominant in biomass, but the family Staphylinidae to be richest in species numbers. Ant studies showed the chaparral community to be rich in ant species; seed gatherers were particularly important. Flower-visiting insects are more abundant and more species-rich in chaparral than in any other...

A probability sampling method called SALT (Selection At List Time) has been developed for collecting and summarizing data on delivery of suspended sediment in rivers. It is based on sampling and estimating yield using a suspended-sediment rating curve for high discharges and simple random sampling for low flows. The method gives unbiased estimates of total yield and variance. The technique has been modified by replacing the rating curve with a user-specified average sampling rate function. This function allows easier specification of field sampling parameters for specified conditions and...

As part of a brief study tour in California, I had the good fortune of spending a very pleasant day on the Caspar Creek watershed, ably guided by Peter Cafferata and Liz Keppeler. Amongst the many notable achievements of the Caspar Creek Study is its longevity. The study started in 1962 and has evolved over time

Spread and buildup of dwarf mistletoe, Arceuthobium abietinum, was studied on inoculated white fir, Abies concolor, and red fir, A. magnifica, in northern California for 23 to 28 years. At the end of these studies (1986), and in the absence of overstory infection, 13 of 23 trees had dwarf mistletoe populations that were the same or smaller than the original populations resulting from inoculation. Mortality of infections was the main factor limiting population increases. Live crown ratio of all trees averaged over 0.8. The average ratio of tree height growth to vertical spread rate of dwarf...

Local volume tables for ponderosa pine (Pinus ponderosa Dougl. ex Laws. var. ponderosa), sugar pine (Pinus lambertiana Dougl.), Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco), California white fir (Abies concolor var. lowiana [Gord.] Lemm.), and incense-cedar (Libocedrus decurrens Torr.) are presented by 1-inch diameter classes in the range of 3 to 40 inches for ponderosa pine, Douglas-fir, California white fir, and incense-cedar. Sugar pine is presented to 45 inches. Trees were measured by an optical dendrometer. Tables are presented for each species in terms of cubic volume to a 0-...