Reliability of macrofossils in woodrat (Neotoma) middens for detecting low-density tree populations

Paleobiology ◽  
2011 ◽  
Vol 37 (4) ◽  
pp. 603-615 ◽  
Author(s):  
Mark R. Lesser ◽  
Stephen T. Jackson
Keyword(s):  
Pinus Ponderosa ◽  
Plant Macrofossils ◽  
Pinus Edulis ◽  
Low Density ◽  
Percent Cover ◽  
Plant Migration ◽  
Local Plant ◽  
Species Population ◽  
Quercus Gambelii ◽  
Individual Trees

Macrofossils from woodrat (Neotoma) middens serve as an important proxy for reconstructing past vegetation in arid and semiarid regions of North America. The presence/absence of plant macrofossils in middens can provide valuable information on temporal and spatial patterns of plant migration and range boundaries. The primary aim of this study was to determine how local plant abundance, distance of plant populations from midden sites, and species population density on the landscape affect the probability of occurrence of macrofossils in middens. The study was designed with the primary intent of determining the reliability of middens in detecting scattered populations of Pinus ponderosa. We analyzed macrofossil assemblages from 42 modern woodrat middens from West Carrizo Canyon in southeastern Colorado, near the current eastern range margin of Pinus ponderosa. We compared midden contents with composition of the surrounding vegetation, measuring distance from the midden to the nearest individual of selected plant species, and the percent cover of each species within 30 m of the midden. We used this information to model the probability of species presence in a midden across a range of population densities on the landscape. Macrofossils of Juniperus spp., Quercus gambelii, and Opuntia spp. were consistently found in middens regardless of their local abundance in vegetation, although populations occurred within 30 m of all middens. Pinus edulis and P. ponderosa occurred in nearly all middens within 20–30 m of individual trees. P. ponderosa was rare in middens >20–30 m away from individual trees. Results of a simple simulation model suggest that middens become absolutely reliable indicators of P. ponderosa presence on the landscape only when average tree density exceeds 50 stems ha−1. Woodrats reliably collected macrofossils of Pinus edulis, P. ponderosa, Juniperus spp., Quercus gambelii, and Opuntia spp. when populations of these taxa occur within 20–30 m of a midden site. Woodrats did not collect P. ponderosa when the nearest individuals were more than 30 m away. Low-density populations of these and other species may be difficult to detect in fossil woodrat-midden series owing to reduced probability that individuals grow within foraging distance of the middens. Data from this and similar studies can be used to construct and parameterize a forward model of macrofossil representation in woodrat middens.

Ponderosa Pine Habitat Types as an Indicator of Site Quality in the Dixie National Forest, Utah

1989 ◽  
Vol 4 (2) ◽  
pp. 52-54 ◽  
Author(s):  
David L. Verbyla ◽  
Richard F. Fisher
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Tree Species ◽  
Habitat Type ◽  
Site Index ◽  
Site Quality ◽  
National Forest ◽  
Habitat Types ◽  
Quercus Gambelii ◽  
Generally True

Abstract Forest habitat types have been purported to be useful indicators of site quality. This is generally true for habitat types with different dominant tree species. However, few have studied the site indicator value of habitat types with the same dominant tree species. We measured site index (base age 25) from 172 randomly selected plots within the ponderosa pine (Pinus ponderosa) zone of the Dixie National Forest, Utah. The range of site index within any one habitat type was broad. Poor sites occurred on all five habitat types. However, the best sites occurred only on the Pinus ponderosa/Symphoricarpos oreophilus and Pinus ponderosa/Quercus gambelii habitat types. Therefore, habitat type may be useful in predicting the best sites, but only if other site information is used in addition to habitat type. West. J. Appl. For. 4(2):52-54, April 1989.

scholarly journals Ponderosa Pine and Lodgepole Pine Growth Response to One-Time Application of Herbicide During Seedling Establishment in Western Montana

2003 ◽  
Vol 18 (3) ◽  
pp. 149-154 ◽  
Author(s):  
Chad E. Keyser ◽  
Kelsey S. Milner
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Seedling Establishment ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Tree Height ◽  
Height Growth ◽  
Western Montana ◽  
Growth Effect ◽  
Percent Cover

Abstract This study examined long-term diameter and height response of ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta var. latifolia) to a one-time application of herbicide during seedling establishment in western Montana. Two herbicide trials initiated in 1981 and 1983 by Champion International Corporation were resurrected during the summer of 1997. Analysis of variance (ANOVA) F-tests along with Duncan's Multiple Range tests (DMR) were performed on mean tree dbh, tree height, and competing vegetation percent cover estimates. In addition, a graphical analysis of mean annual height growth over time was performed. Significant increases (alpha = 0.05) in ponderosa pine dbh (25 to 44%) and height (11 to 28%) were found after 16 yr of growth on Velpar L. (hexazinone) treated plots, while lodgepole pine had significant increases in dbh (70 to 118%) and height (41 to 82%) after 15 yr of growth on Velpar L. treated plots. Graphical analyses indicated a positive height growth effect for a period of 11 to 13 yr following treatment for ponderosa pine; however, total height gains had decreased in recent years. Positive increases in height growth for lodgepole pine were continuing after 15 yr of growth. These results indicate that a one-time application of herbicide applied during seedling establishment will promote faster tree growth in western Montana. We also note that proper density management will be necessary early in the life of the stand to maintain height gains. West. J. Appl. For. 18(3):149–154.

scholarly journals Influences of Conventional and Low-Density Thinning on the Lower Bole Taper and Volume Growth of Eastern White Pine

2011 ◽  
Vol 28 (3) ◽  
pp. 123-128 ◽  
Author(s):  
Christopher H. Guiterman ◽  
Aaron R. Weiskittel ◽  
Robert S. Seymour
Keyword(s):  
Management Practice ◽  
Volume Growth ◽  
The Other ◽  
Low Density ◽  
White Pine ◽  
Eastern White Pine ◽  
Breast Height ◽  
Crown Thinning ◽  
Individual Trees ◽  
Density Treatment

Abstract Throughout the northeastern United States, thinning is a common management practice in stands of eastern white pine (Pinus strobus L.), but foresters lack clear information as to whether conventional B-line or low-density thinning will best achieve their growth and financial objectives. Conventional management consists primarily of light crown thinning, whereas low-density management uses heavy crown thinning to isolate selected crop trees. To better inform silviculturists of the effects of these thinning regimes on volume growth and taper of white pine, we compared the lower bole taper—quantified as Girard form class (GFC)—and volume growth between the two thinning regimes and a nonthinned control. Over the 17-year study period, GFC increased among all treatments from an overall average of 0.77 — 0.01 (—SE) to 0.82 — 0.00. Trees under the B-line thinning regime had the most taper (lowest GFC), owing to a thinning-induced growth response at breast height but not at the top of the butt log. Low-density thinning, on the other hand, resulted in substantially larger, less tapered butt logs with significantly higher growth rates at both breast height and the top of the butt log. The volume growth of low-density trees was significantly higher than that of trees in the other treatments. At the stand level, however, the overall volume growth of the low-density treatment was significantly lower than that of the B-line treatment. Thus, this study reveals that when implementing low-density thinning, there is a tradeoff between overall stand growth and larger, less tapered individual trees.

Prediction of delayed mortality of fire-damaged ponderosa pine following prescribed fires in eastern Oregon, USA

2006 ◽  
Vol 15 (1) ◽  
pp. 19 ◽  
Author(s):  
Walter G. Thies ◽  
Douglas J. Westlind ◽  
Mark Loewen ◽  
Greg Brenner
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Management Tool ◽  
Experimental Unit ◽  
Full Model ◽  
Prescribed Burns ◽  
Blue Mountains ◽  
Growing Seasons ◽  
Individual Trees

Prescribed burning is a management tool used to reduce fuel loads in western interior forests. Following a burn, managers need the ability to predict the mortality of individual trees based on easily observed characteristics. Astudy was established in six stands of mixed-age ponderosa pine (Pinus ponderosa Dougl. ex Laws.) with scattered western junipers at the south end of the Blue Mountains near Burns, Oregon, USA. Stands were thinned in either 1994 or 1995. Three treatments, a fall burn, a spring burn, and an unburned control, were randomly assigned to 12-ha experimental units within each stand. Prescribed burns occurred during mid-October of 1997 or mid-June of 1998 and were representative of operational burns, given weather and fuel conditions. Within each experimental unit, six 0.2-ha plots were established to evaluate responses to the burns. Ponderosa pine plot trees (n =3415) alive 1 month after the burns were evaluated and observed for four growing seasons. Nine fire damage and tree morphological variables were evaluated by logistic regression. A five-factor full model and a two-factor reduced model are presented for projecting probability of mortality. Significant variables in the full model included measures of crown, bole, and basal damage.

The effect of competition from different weed species on the growth of Betula pendula seedlings

2006 ◽  
Vol 36 (8) ◽  
pp. 1900-1912 ◽  
Author(s):  
Ian Willoughby ◽  
David V Clay ◽  
Fiona L Dixon ◽  
Geoff W Morgan
Keyword(s):  
Lolium Perenne ◽  
Tree Growth ◽  
Betula Pendula ◽  
Percent Cover ◽  
Inhibitory Effects ◽  
Weed Species ◽  
Cirsium Vulgare ◽  
Weed Growth ◽  
Local Plant ◽  
Woodland Regeneration

The identification of less competitive weed species and infestation rates might allow weeding operations to be better targeted, help conserve local plant biodiversity, and facilitate reductions in the amount of herbicide used to achieve woodland regeneration. Therefore, the effect of competition from pure stands of Cirsium vulgare (Savi) Ten., Epilobium ciliatum Raf., Holcus lanatus L., Poa annua L., and Persicaria maculosa Gray on Betula pendula Roth was investigated over 2 years. All weed species reduced tree growth significantly compared with weed-free plots, but there were no significant differences among species. When Lolium perenne L., Rumex obtusifolius L., and Cirsium vulgare were established at four densities in plots containing newly planted B. pendula over a 1-year period, all weed species reduced tree growth, but Lolium perenne was the most competitive. Weed density had no significant effect, indicating that even sparse weed growth can have a major impact on tree performance. None of the treatments affected B. pendula survival. These results confirm the inhibitory effects of a range of weed species on tree growth, but not survival, and the capacity of B. pendula to recover in the second year after planting from an initial check in growth. Percent cover was a good explanatory variable for models developed to describe the effects of weeds on tree growth, and preliminary competition indices for the different species are presented.

scholarly journals Fire Effects and Fire History of Mesa Verde National Park

1991 ◽  
Vol 15 ◽  
pp. 199-202
Author(s):  
Lisa Floyd-Hanna ◽  
Ken Heil ◽  
Bill Romme
Keyword(s):  
National Park ◽  
Fire History ◽  
Fire Effects ◽  
Perennial Grasses ◽  
Pinus Edulis ◽  
Juniperus Osteosperma ◽  
The North ◽  
Mesa Verde ◽  
History Of ◽  
Quercus Gambelii

Mesa Verde consists of a series of mesas in a north to south trend. The mesa tops are narrow strips, cut by numerous canyons of varying depth. Mesa Verde sandstones, particularly the Cliff House Formation, form the canyon slopes. Long Mesa, an area of focus in this study, has an elevation 2180 m at the south to 2517 m at the north end. Long Canyon cuts down to an elevation of 2133 m. The vegetation on Long Mesa is a mosaic of mature pinon-juniper woodlands and mountain shrub associations. Shrub associations range from Gambels oak, (Quercus gambelii), and serviceberry, (Amelancheir utahensis), to Black Sagebrush, (Artemesia nova), and Bitterbrush, (Purshia tridentata). Although there is a body of information concerned with the effect of fire on pinon-juniper woodlands, there are no adequate studies of the shrub-rich pinon­juniper ecosystem of Colorado. Succession following fire was documented by Erdman (1970) in Mesa Verde National Park. He reported that annuals dominate initially, then perennial grasses and forbs, followed by shrub invasion. The open shrub stage becomes a "thicket" approximately 100 years after the fire. The shrubs, he suggests, are outcompeted by pinon (Pinus edulis) and juniper trees (Juniperus osteosperma), which dominate by about 300 years.

Lophodermella cerina. [Descriptions of Fungi and Bacteria].

1993 ◽  
Author(s):  
D. W. Minter
Keyword(s):  
New Mexico ◽  
Pinus Taeda ◽  
Geographical Distribution ◽  
Pinus Ponderosa ◽  
Pinus Contorta ◽  
Pinus Elliottii ◽  
First Year ◽  
Needle Cast ◽  
Individual Trees ◽  
Significant Mortality

Abstract A description is provided for Lophodermella cerina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Pinus contorta, Pinus elliottii var. elliottii, Pinus ponderosa, Pinus taeda. DISEASES: Needle cast of pines. Symptoms on first-year needles have been reported to appear in November on southern pines, with the ascomata visible by late February and prominent by the end of March. Czabator et al. (1971) stated that two years' needles are affected, though it is not clear whether this means there are two sets of infected needles on a tree at the same time. All ages of pines in the southern USA have been reported to be infected, though the disease was more common in older stands, and while the infection was scattered within a stand, whole crowns of individual trees are affected. Severe and repeated attacks by L. cerina on pine species in the western USA did not cause significant mortality. GEOGRAPHICAL DISTRIBUTION: USA (Alabama, Arizona, California, Colorado, Florida, Louisiana, Mississippi, New Mexico). TRANSMISSION: By airborne ascospores in wet or humid conditions.

scholarly journals Ponderosa Pine Growth Response to Soil Strength in the Volcanic Ash Soils of Central Oregon

2007 ◽  
Vol 22 (2) ◽  
pp. 134-141 ◽  
Author(s):  
Robert T. Parker ◽  
Douglas A. Maguire ◽  
David D. Marshall ◽  
Pat Cochran
Keyword(s):  
Tree Growth ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Volcanic Ash ◽  
Volume Growth ◽  
Timber Harvesting ◽  
Soil Strength ◽  
Individual Trees ◽  
Volcanic Ash Soils

Abstract Mechanical harvesting and associated logging activities have the capacity to compact soil across large portions of harvest units, but the influences of compaction on long-term site productivity are not well understood. Previous research in central Oregon has shown that volcanic ash soils compact readily under both compression and vibration loads, resulting in long-term alteration in soil density and a decline in tree growth. In this study, soil strength (SS) and tree growth were assessed in areas subject to repeated timber harvesting with the objective of quantifying the relationship between ponderosa pine (Pinus ponderosa Laws.) growth and SS. Two thinning treatments (felled only versus felled and skidded) in 70- to 80-year-old ponderosa pine stands were replicated at three sites in 1991. Subsequent 5-year growth in diameter, height, and volume of residual trees were assessed with respect to SS measured by a recording penetrometer. Felled and skidded plots had 44% higher SS values than felled-only plots (P = 0.05). Although no treatment effect on growth was detected at the plot level, diameter, height, and volume growth of individual trees within plots declined significantly as average SS within a 30-ft zone of influence increased from approximately 800 to 2,500 kPa. Results show the potential use of SS measurements for monitoring impacts of harvesting operations on tree growth.

scholarly journals Testing the Use of Bomb Radiocarbon to Date the Surface Layers of Blanket Peat

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 841-851 ◽  
Author(s):  
M H Garnett ◽  
A C Stevenson
Keyword(s):  
Mass Spectrometry ◽  
Plant Material ◽  
Plant Macrofossils ◽  
Low Density ◽  
Surface Layers ◽  
Broad Agreement ◽  
Blanket Peat ◽  
Bomb Radiocarbon ◽  
Final Interpretation

The recently formed surface layers of peatlands are archives of past environmental conditions and can have a temporal resolution considerably greater than deeper layers. The low density and conditions of fluctuating water table have hindered attempts to construct chronologies for these peats. We tested the use of the radiocarbon bomb pulse to date recently accumulated peat in a blanket mire. The site was chosen because the peat profiles contained independent chronological markers in the form of charcoal-rich layers produced from known burning events. We compared chronologies derived from accelerator mass spectrometry 14C analysis of plant macrofossils against these chronological markers. The bomb 14C-derived chronologies were in broad agreement with the charcoal dating evidence. However, there were uncertainties in the final interpretation of the 14C results because the pattern of 14C concentration in the peat profiles did not follow closely the known atmospheric 14C record. Furthermore, samples of different macrofossil materials from the same depth contained considerable differences in 14C. Suggested explanations for the observed results include the following: i) minor disturbance at the site, ii) in-situ contamination of the 14C samples by carbonaceous soot, and iii) differential incorporation of plant material during blanket peat growth.

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