Simulating Succession of Riparian Spruce Forests and White-Tailed Deer Carrying Capacity in Northwestern Montana

1987 ◽  
Vol 2 (3) ◽  
pp. 80-83 ◽  
Author(s):  
Kurt J. Jenkins ◽  
R. Gerald Wright
Keyword(s):  
Carrying Capacity ◽  
River Flow ◽  
Populus Trichocarpa ◽  
Timber Harvesting ◽  
Resource Monitoring ◽  
Black Cottonwood ◽  
Winter Range ◽  
Erosion Rates ◽  
The North ◽  
North Fork

Abstract Rates of succession were determined during the period 1945-80 in six floodplain plant communities along the North Fork of the Flathead River, Montana. A succession model was developed to forecast the long-range effects of land-use change on the carrying capacity of white-tailed deer winter range. The areas occupied by mature spruce (Picea englemannii x glauca hybrid) and spruce-black cottonwood (Populus trichocarpa) forests on the floodplain were relatively constant between 1945-1980. Early seral types were more variable due to short-term variations in river flow. Successional modelling demonstrated the effects of two timber harvesting strategies on white-tailed deer populations. Simulated populations declined following two timber harvesting schedules, but recovered after cessation of harvest. An additional application of the model showed the potential effects of increased erosion rates on deer populations and demonstrated the versatility of land succession models for resource monitoring. West. J. Appl. For. 2(3):80-83, July 1987

scholarly journals Bedrock gorge incision via anthropogenic meander cutoff

Geology ◽  
2021 ◽  
Author(s):  
Adrian M. Bender
Keyword(s):  
Gradual Transition ◽  
Historical Records ◽  
Erosion Rates ◽  
Base Level ◽  
The North ◽  
Shaping Process ◽  
North Fork ◽  
Formation Experiment ◽  
Level Lowering ◽  
Local Base

Bedrock river-gorge incision represents a fundamental landscape-shaping process, but a dearth of observational data at >10 yr timescales impedes understanding of gorge formation. I quantify 102 yr rates and processes of gorge incision using historical records, field observations, and topographic and image analysis of a human-caused bedrock meander cutoff along the North Fork Fortymile River in Alaska (USA). Miners cut off the meander in 1900 CE, abruptly lowering local base level by 6 m and forcing narrowing and steepening of the channel across a knickpoint that rapidly incised upstream. Tectonic quiescence, consistent rock erosivity, and low millennial erosion rates provide ideal boundary conditions for this 102 yr gorge-formation experiment. Initial fast knickpoint propagation (23 m/yr; 1900–1903 CE) slowed (4 m/yr; 1903–1981 CE) to diffusion (1981–2019 CE) as knickpoint slope decreased, yielding an ~350-m-long, 6-m-deep gorge within the pre–1900 CE channel. Today, diffusion dominates incision of a 500-m-long knickzone upstream of the gorge, where sediment transport likely limits ongoing adjustments to the anthropogenic cutoff. Results elucidate channel width, slope, discharge, and sediment dynamics consistent with a gradual transition from detachment- to transport-limited incision in fluvial adjustment to local base-level lowering.

Sources of Chlorophenolic Compounds to the Fraser River Estuary

1988 ◽  
Vol 23 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J. H. Carey ◽  
J. H. Hart
Keyword(s):  
River Flow ◽  
River Estuary ◽  
Low Flow ◽  
Fraser River ◽  
Pulp Mills ◽  
Flow Conditions ◽  
Downstream Site ◽  
Upstream Site ◽  
The North ◽  
Main River

Abstract The identity and concentrations of chlorophenolic compounds in the Fraser River estuary were determined under conditions of high and low river flow at three sites: a site upstream from the trifurcation and at downstream sites for each main river arm. Major chlorophenolics present under both flow regimes were 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), pentachlorophenol (PCP), tetrachloroguaiacol (TeCG) and a compound tentatively identified as 3,4,5-trichloroguaiacol (3,4,5-TCG). Under high flow conditions, concentrations of the guaiacols were higher than any of the Chlorophenols and concentrations of all five chlorophenolics appeared to correlate. Under low flow conditions, concentrations of chloroguaiacols were higher than Chlorophenols at the upstream site and at the downstream site on the Main Arm, whereas at the downstream site on the North Arm, concentrations of 2,3,4,6-TeCP and PCP were higher than the chloroguaiacols in some samples. Overall, the results indicate that pulp mills upstream from the estuary are important sources of chlorophenolics to the estuary under all flow conditions. Additional episodic inputs of 2,3,4,6-TeCP and PCP from lumber mills occur along the North Arm. When these inputs occur, they can cause the concentrations of Chlorophenols in the North Arm to exceed provisional objectives. If chloroguaiacols are included as part of the objective, concentrations of total chlorophenolics in water entering the estuary can approach and exceed these objectives, especially under low flow conditions.

scholarly journals A peroxisomal β-oxidative pathway contributes to the formation of C6–C1 aromatic volatiles in poplar

2021 ◽  
Author(s):  
Nathalie D Lackus ◽  
Axel Schmidt ◽  
Jonathan Gershenzon ◽  
Tobias G Köllner
Keyword(s):  
Cinnamic Acid ◽  
Aromatic Compounds ◽  
Populus Trichocarpa ◽  
Alternative Pathway ◽  
Gene Families ◽  
Defense Responses ◽  
In Planta ◽  
Black Cottonwood ◽  
Oxidative Pathway

AbstractBenzenoids (C6–C1 aromatic compounds) play important roles in plant defense and are often produced upon herbivory. Black cottonwood (Populus trichocarpa) produces a variety of volatile and nonvolatile benzenoids involved in various defense responses. However, their biosynthesis in poplar is mainly unresolved. We showed feeding of the poplar leaf beetle (Chrysomela populi) on P. trichocarpa leaves led to increased emission of the benzenoid volatiles benzaldehyde, benzylalcohol, and benzyl benzoate. The accumulation of salicinoids, a group of nonvolatile phenolic defense glycosides composed in part of benzenoid units, was hardly affected by beetle herbivory. In planta labeling experiments revealed that volatile and nonvolatile poplar benzenoids are produced from cinnamic acid (C6–C3). The biosynthesis of C6–C1 aromatic compounds from cinnamic acid has been described in petunia (Petunia hybrida) flowers where the pathway includes a peroxisomal-localized chain shortening sequence, involving cinnamate-CoA ligase (CNL), cinnamoyl-CoA hydratase/dehydrogenase (CHD), and 3-ketoacyl-CoA thiolase (KAT). Sequence and phylogenetic analysis enabled the identification of small CNL, CHD, and KAT gene families in P. trichocarpa. Heterologous expression of the candidate genes in Escherichia coli and characterization of purified proteins in vitro revealed enzymatic activities similar to those described in petunia flowers. RNA interference-mediated knockdown of the CNL subfamily in gray poplar (Populus x canescens) resulted in decreased emission of C6–C1 aromatic volatiles upon herbivory, while constitutively accumulating salicinoids were not affected. This indicates the peroxisomal β-oxidative pathway participates in the formation of volatile benzenoids. The chain shortening steps for salicinoids, however, likely employ an alternative pathway.

Organ culture with black cottonwood: morphogenetic response of female catkin primordia

1972 ◽  
Vol 50 (7) ◽  
pp. 1627-1631 ◽  
Author(s):  
K. S. Bawa ◽  
R. F. Stettler
Keyword(s):  
Organ Culture ◽  
Vegetative Growth ◽  
Callus Formation ◽  
Populus Trichocarpa ◽  
General Tendency ◽  
Black Cottonwood ◽  
Axillary Shoots ◽  
Female Sex ◽  
Female Catkin

Female catkin primordia of black cottonwood (Populus trichocarpa T. & G. ex Hook.) were cultured for 70 days on a modified Murashige and Skoog's (1962) medium in vitro. Explants 2–3 mm long, and with bud scales removed, gave the best results, many of them developing floral structures characteristic of the female sex. There was a general tendency to callus formation with increasing age of the culture, occasionally followed by a reversal to vegetative growth. Catkin primordia raised on Wolter's medium without auxin or kinetin, but with 6-benzylaminopurine, and at 250 ft-c for a 16-h photoperiod, proliferated axillary shoots in loco of pistils.

Ecotypic mode of regional differentiation caused by restricted gene migration: a case in black cottonwood (Populus trichocarpa) along the Pacific Northwest coast

2009 ◽  
Vol 39 (3) ◽  
pp. 519-525 ◽  
Author(s):  
Chang-Yi Xie ◽  
Cheng C. Ying ◽  
Alvin D. Yanchuk ◽  
Diane L. Holowachuk
Keyword(s):  
Genetic Differentiation ◽  
Pacific Northwest ◽  
Populus Trichocarpa ◽  
Common Garden ◽  
Northern Region ◽  
Regional Differentiation ◽  
Black Cottonwood ◽  
Gene Migration ◽  
Geographic Patterns ◽  
Leaf Flushing

Genetic differentiation of black cottonwood ( Populus balsamifera subsp. trichocarpa (Torr. & A. Gray ex Hook) Brayshaw) across a “no-cottonwood” belt on the coast of central British Columbia (BC), Canada, was examined using data on 3 year height, severity of infection by Valsa sordida Nitschke and Melampsora occidentalis H. Jacks., and abnormality of leaf flushing. The data were collected in a common-garden test consisting of 180 provenances of 36 drainages ranging from northern BC to Oregon, USA. The results demonstrated an ecotypic mode, north–south regional differentiation. Valsa sordida and M. occidentalis infected 41% and 89%, respectively, of the trees from the northern region, while 66% showed flushing abnormality. In contrast, only 1% and 27% of their southern counterparts were infected by the same diseases, and 1% had abnormal flushing. Trees from the northern region averaged 87% shorter than those from the south. Regional differentiation accounted for the highest amount of variation observed in all traits, with 60% in 3 year height, 34% in V. sordida, 76% in M. occidentalis, and 50% in abnormal leaf flushing. Regression analysis revealed geographic patterns that essentially reflected regional differentiation along the no-cottonwood belt. The species’ distribution biography, ecological characteristics, and life history suggest that restricted gene migration was the main factor responsible for the observed geographic patterns of genetic differentiation.

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