Serotiny and life history of Pinus contorta var. latifolia

1985 ◽  
Vol 63 (5) ◽  
pp. 938-945 ◽  
Author(s):  
Patricia S. Muir ◽  
James E. Lotan
Keyword(s):  
Life History ◽  
Gene Flow ◽  
Pinus Contorta ◽  
Reproductive Effort ◽  
Basal Area ◽  
Western Montana ◽  
Tree Age ◽  
Selective Pressures ◽  
Area Growth ◽  
History Of

Mature serotinous and nonserotinous trees of Pinus contorta Dougl. var. latifolia Engelm. in the Bitterroot Watershed of western Montana do not differ in most life-history characteristics (reproductive or vegetative). No differences between trees of the two cone types were found in height, basal area, basal area growth rates over the lives of the trees, or crown ratio. Cone number, weights of individual cones and seeds, and estimates of reproductive effort were similar in serotinous and non-serotinous trees. Reproductive characteristics were either independent of tree age, or related similarly in trees of the two cone types. Nonserotinous trees may, however, have more seeds per cone than serotinous trees. This difference in seed numbers may be adaptive if serotinous trees invest relatively heavily in cone materials to protect seeds (which are retained in cones for many years), while nonserotinous trees (which shed seeds each year) invest relatively heavily in seeds. Trees of the two cone types differ mainly in the particular types of disturbance favoring their regeneration, but they often grow in the same stands where there are similar selective pressures on most aspects of their biology. Gene flow between them probably homogenizes all but those differences maintained by strong selective pressures.

Gene flow from domesticated escapes alters the life history of wild Atlantic salmon

2017 ◽  
Vol 1 (5) ◽  
Author(s):  
Geir H. Bolstad ◽  
Kjetil Hindar ◽  
Grethe Robertsen ◽  
Bror Jonsson ◽  
Harald Sægrov ◽  
...  
Keyword(s):  
Life History ◽  
Gene Flow ◽  
Atlantic Salmon ◽  
History Of

Assessment of sugar maple health based on basal area growth pattern

2003 ◽  
Vol 33 (11) ◽  
pp. 2074-2080 ◽  
Author(s):  
Louis Duchesne ◽  
Rock Ouimet ◽  
Claude Morneau
Keyword(s):  
Growth Pattern ◽  
Acer Saccharum ◽  
Radial Growth ◽  
Sugar Maple ◽  
Basal Area ◽  
Tree Age ◽  
Tree Health ◽  
Health Decline ◽  
Area Growth ◽  
Natural Range

The first tree health decline symptoms usually observed are foliar deficiency symptoms, foliage loss, and dieback. To improve the subjective nature and unspecificity of these assessments, we examined sugar maple (Acer saccharum Marsh.) radial growth and health to develop an indicator of sugar maple tree health status based on radial growth pattern. We used the basal area increment (BAI) of 328 tree-ring collections from 16 sites located in southern Quebec, throughout the sugarbush natural range, that were categorized by defoliation class. BAI of trees with decline symptoms was significantly lower than that of healthy trees in 9 of the 16 stands. BAI trends since 1955 showed an inverse relationship with tree decline class measured in 1989, irrespective of tree age. The results indicate that declining trees in these stands have not recovered based on BAI. They also suggest that the decrease in slope of BAI predated the observed symptoms of sugar maple decline by at least one decade. Results suggest that sugar maple vigor and health can be assessed by measuring tree's BAI trend, an indicator that may be useful for the diagnosis of sugar maple health and status years before the appearance of visible canopy symptoms.

scholarly journals Life history of a secondary bark beetle, Pseudips mexicanus (Coleoptera: Curculionidae: Scolytinae), in lodgepole pine in British Columbia

2009 ◽  
Vol 141 (1) ◽  
pp. 56-69 ◽  
Author(s):  
G.D. Smith ◽  
A.L. Carroll ◽  
B.S. Lindgren
Keyword(s):  
Life History ◽  
Bark Beetle ◽  
Pinus Contorta ◽  
Life History Traits ◽  
Lodgepole Pine ◽  
Degree Days ◽  
Northern Portion ◽  
History Of ◽  
Bark Beetle Associates

AbstractPseudips mexicanus (Hopkins) is a secondary bark beetle native to western North and Central America that attacks most species of pine (Pinus L. (Pinaceae)) within its range. A pair of life-history studies examined P. mexicanus in other host species, but until now, no work has been conducted on lodgepole pine (Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson). Pseudips mexicanus in lodgepole pine was found to be polygynous. Galleries were shorter, offspring smaller, and the eggs laid per niche and the potential progeny fewer than in populations from California and Guatemala. Development from the time of female attack to emergence of adult offspring took less than 50 days at 26.5 °C, and the accumulated heat required to complete the life cycle was determined to be 889.2 degree days above 8.5 °C, indicating that in the northern portion of its range P. mexicanus is univoltine. Determination of these life-history traits will facilitate study of interactions between P. mexicanus and other bark beetle associates in lodgepole pine.

scholarly journals Evolution of morphological and climatic adaptations inVeronica L.(Plantaginaceae)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2333 ◽  
Author(s):  
Jian-Cheng Wang ◽  
Bo-Rong Pan ◽  
Dirk C. Albach
Keyword(s):  
Life History ◽  
Substitution Rate ◽  
Parallel Evolution ◽  
Morphological Characters ◽  
Annual Species ◽  
Selective Pressures ◽  
History Of ◽  
Phylogenetic Perspective ◽  
Drought Resistant ◽  
Annual Life History

Perennials and annuals apply different strategies to adapt to the adverse environment, based on ‘tolerance’ and ‘avoidance’, respectively. To understand lifespan evolution and its impact on plant adaptability, we carried out a comparative study of perennials and annuals in the genusVeronicafrom a phylogenetic perspective. The results showed that ancestors of the genusVeronicawere likely to be perennial plants. Annual life history ofVeronicahas evolved multiple times and subtrees with more annual species have a higher substitution rate. Annuals can adapt to more xeric habitats than perennials. This indicates that annuals are more drought-resistant than their perennial relatives. Due to adaptation to similar selective pressures, parallel evolution occurs in morphological characters among annual species ofVeronica.

Ecological Life-History of the Larch Sawfly, Pristiphora erichsonii (Htg.) (Hymenoptera: Tenthredinidae), in Manitoba and Saskatchewan

1960 ◽  
Vol 92 (7) ◽  
pp. 500-516 ◽  
Author(s):  
W. J. Turnock
Keyword(s):  
United States ◽  
Life History ◽  
The United States ◽  
Western Montana ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
History Of ◽  
Lake States ◽  
Holarctic Region ◽  
North Western

The larch sawfly is a common defoliator of trees of the genus Larix throughout the Holarctic Region. In North America it has been reported from every province of Canada but in the United States it is confined to the northeastern States, the Lake States, and north-western Montana (Drooz, 1956). The northern limits of distribution have not been determined, but extend as far as 61° N. lat. north of Saskatchewan.

Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals

1999 ◽  
Keyword(s):  
Life History ◽  
Management Plan ◽  
Fishing Effort ◽  
Life History Strategies ◽  
Shark Species ◽  
Fishing Pressure ◽  
Marine Animals ◽  
Selective Pressures ◽  
Stock Assessments ◽  
History Of

<em> Abstract.</em>—Sharks have the reputation of being particularly vulnerable to fishing pressure, a fact attributed to their generally ‘<EM> K</EM>-selected’ life history strategies. The history of shark fisheries is not encouraging, and their poor record of sustainability is compounded by the fact that few countries have any form of management for these resources. The Australian Southern Shark Fishery provides an example of a well-studied shark fishery with a long history of exploitation that has been under a management plan for some ten years. This fishery is unique in that it exploits, under a similar fishing regime, two similar target shark species that show very different responses to fishing pressure. Stock assessments suggest that under current fishing effort the catch of one species is sustainable while the other species is overexploited. The vulnerability of the two species to the fishing gear is similar but their biological productivity is very different. The selective pressures that may have given rise to these different life history strategies are discussed.

Factors affecting the relationship between sapwood area and leaf area of balsam fir

1992 ◽  
Vol 22 (11) ◽  
pp. 1684-1693 ◽  
Author(s):  
Marie R. Coyea ◽  
Hank A. Margolis
Keyword(s):  
Leaf Area ◽  
Basal Area ◽  
Tree Height ◽  
Balsam Fir ◽  
Tree Age ◽  
Cross Sectional ◽  
Sapwood Area ◽  
Crown Length ◽  
Basal Area Growth ◽  
Area Growth

The ratio between projected leaf area (LA) and cross-sectional sapwood area (SA) of dominant and codominant balsam fir trees (Abiesbalsamea (L.) Mill.) was determined in 24 forest stands across the province of Quebec. Various physical factors proposed in the Whitehead hydraulic model, and some of the easily measured surrogates of these factors, were tested for their influence on LA:SA ratios. Average growing season vapor pressure deficit, temperature, precipitation, and stand drainage class did not significantly influence LA:SA ratios. On the other hand, LA:SA ratios were positively influenced by sapwood permeability (k), tree height, and crown length. As suggested by the model, there was a positive correlation between sapwood permeability and LA:SA ratio and a negative correlation between tree height or crown length and LA/(SA k). Increases in sapwood permeability with tree age were associated with longer tracheids having larger lumen diameters. Of the various empirical factors tested, only site quality, 5-year basal area growth, and age had a significant influence on LA:SA ratios. Sapwood cross-sectional area at breast height by itself was a reasonable linear predictor of LA for all stands (LA = −0.158 + 0.709 SABH, R2 = 0.75). Using the variables that were previously determined to influence LA:SA ratios, stepwise regressions revealed that only crown length and 5-year basal area growth significantly improved linear predictions of LA based on sapwood area. However, the increase in R2 was relatively modest, i.e., 0.83 for all three independent variables versus 0.75 for SA alone. The results from this study will be useful in integrating physiologically based measurements, such as growth efficiency, into standard forest inventory practices for balsam fir and thus could be beneficial in developing new silvicultural strategies for protecting Quebec's forest resource.

scholarly journals Geography is more important than life history in the recent diversification of the tiger salamander complex

2020 ◽  
Author(s):  
Kathryn M. Everson ◽  
Levi N. Gray ◽  
Angela G. Jones ◽  
Nicolette M. Lawrence ◽  
Mary E. Foley ◽  
...  
Keyword(s):  
Life History ◽  
Gene Flow ◽  
Life History Strategies ◽  
Conservation Priorities ◽  
Tiger Salamander ◽  
Life History Variation ◽  
Wide Range ◽  
History Of ◽  
Lineage Divergence ◽  
Salamander Species

AbstractThe North American tiger salamander species complex, including its flagship species the axolotl, has long been a source of biological fascination. The complex exhibits a wide range of variation in developmental life history strategies, including populations and individuals that undergo metamorphosis and those able to forego metamorphosis and retain a larval, aquatic lifestyle (i.e., paedomorphosis). Such disparate life history strategies are assumed to cause populations to become reproductively isolated, but the degree to which they have actually shaped population- and species-level boundaries is poorly understood. Using a large multi-locus dataset from hundreds of samples across North America, we identified genetic clusters with clear signs of admixture across the geographic range of the tiger salamander complex. Population clusters often contain a mixture of paedomorphic and metamorphic taxa, and we conclude that geography has played a large role in driving lineage divergence relative to obligate paedomorphosis in this system. This conclusion is bolstered by model-based analyses demonstrating gene flow between metamorphic and paedomorphic populations. Even the axolotl, a paedomorphic species with an isolated native range, apparently has a history of gene flow with its neighboring populations. This fine-scale genetic perspective on life-history variation establishes a framework for understanding how plasticity, local adaptation, and gene flow contribute to lineage divergence. The axolotl is currently used as the vertebrate model system in regenerative biology, and our findings chart a course for more informed use of these and other tiger salamander species in experimental and field research, including conservation priorities.Significance StatementPopulation structure and speciation are shaped by a variety of biotic and abiotic factors. In the tiger salamander complex, one factor that may influence diversification is life history: some taxa are obligately paedomorphic–a condition where adults maintain an aquatic, larval phenotype–while others are facultatively paedomorphic or entirely metamorphic. Using a large multi-locus dataset, we found evidence of gene flow and/or panmixia between obligately and facultatively paedomorphic taxa, suggesting that an obligately paedomorphic life history is not a strong driver of speciation in the tiger salamander complex. We also recovered a history of gene flow between the critically endangered axolotl and its neighboring populations, providing important information for its conservation and captive management.

Coarse woody debris in sub-boreal spruce forests of west-central British Columbia

1998 ◽  
Vol 28 (2) ◽  
pp. 284-290 ◽  
Author(s):  
D F Clark ◽  
D D Kneeshaw ◽  
P J Burton ◽  
J A Antos
Keyword(s):  
British Columbia ◽  
Coarse Woody Debris ◽  
Picea Glauca ◽  
Boreal Forests ◽  
Pinus Contorta ◽  
Woody Debris ◽  
Basal Area ◽  
Stand Age ◽  
Abies Lasiocarpa ◽  
History Of

An evaluation of how coarse woody debris (CWD) changes in quantity and quality during stand development was conducted using a 426-year chronosequence of 71 stands in sub-boreal forests in British Columbia. Additional characteristics of CWD were determined in 14 of the stands. Most stands are fire initiated and input from the predisturbance stand is critical in controlling the amounts and characteristics of CWD within young stands. Log volume declines from over 100 m3/ha in young stands (0-50 years) to just over 60 m3/ha in stands from 51 to 200 years old, and then increases to greater than 140 m3/ha in the oldest (>= 400-year-old) stands. Mean snag basal area is highest (31.6 m2/ha) in young, postfire stands, decreases to a very low value (2.0 m2/ha) in stands 51-100 years old, and then reaches a second maximum (12.1 m2/ha) in stands that are 201-250 years old; it declines slightly in very old stands. The high snag basal area in stands 201-250 years old coincides with the successional transition from lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) to stands dominated by subalpine fir (Abies lasiocarpa (Hook.) Nutt.) and interior spruce (hybrids of Picea glauca (Moench) Voss and Picea engelmannii Parry). Stand age, characteristics of the predisturbance forest, and the disturbance history of stands subsequent to stand initiation all appear to be very important in determining variation in both the quality and quantity of CWD in these sub-boreal forests.

BIOLOGY AND LIFE HISTORY OF EPURAEA OBLIQUUS HATCH (COLEOPTERA: NITIDULIDAE) ON WESTERN GALL RUST

1996 ◽  
Vol 128 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Cameron R. Currie ◽  
John R. Spence ◽  
W. Jan A. Volney
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Late Summer ◽  
Natural Control ◽  
Larval Instars ◽  
Endocronartium Harknessii ◽  
History Of ◽  
The Impact

AbstractThe life cycle, phenology, and abundance of Epuraea obliquus Hatch was studied near Hinton, Alberta. Most of the life cycle occurs on galls of Endocronartium harknessii (J.P. Moore) Y. Hiratsuka (western gall rust) infecting lodgepole pine (Pinus contorta Dougl. var latifolia Engelm.). Both adults and larvae feed on the spores of the fungus. Individuals of this beetle were found on most galls sampled. Adults overwinter in the soil. They emerge in the spring to seek out and colonize galls. Eggs are laid on the surface of galls, mainly under the periderm, and larvae feed on the fungus, developing through three larval instars. Larvae in the last instar drop from galls to pupate in the soil. Adults leave the soil in late summer and return to feed on inactive galls before overwintering in the soil. The phenology of E. obliquus is closely synchronized with the timing of rust sporulation and the impact of beetle feeding may be an important natural control of western gall rust.

Sign in / Sign up

Export Citation Format

Share Document