Late-glacial climate and ecology of a kettle section at Brampton, Ontario, Canada, as determined from fossil Coleoptera

1997 ◽  
Vol 34 (7) ◽  
pp. 926-934 ◽  
Author(s):  
John E. Motz ◽  
Alan V. Morgan

A 5 m sequence of organic-rich sediments (ca. 13 000 years BP to ca. 4500 BP) from a drained glacial kettle pond near Brampton, Ontario, has yielded a rich and varied assemblage of coleopteran fossils. This paper discusses the beetles recovered from the basal 1 m of the section (ca. 13 000 to 12 500 BP), which represent the earliest phase of deposition in the kettle, prior to the final melt-out of underlying ice. The species are typical of northern boreal or tree-line habitats today. They illustrate that during this time the landscape was predominantly open ground, with herb and shrub vegetation. Individual trees or isolated clumps of conifers were nearby, as suggested by the presence of scolytids (bark beetles). The mean July temperature was in the range from 12.5 to 15 °C, indicating that the lack of trees is a lag effect in colonization, perhaps due to unsuitable substrate conditions rather than to an unfavourable climate.

1979 ◽  
Vol 12 (2) ◽  
pp. 226-240 ◽  
Author(s):  
Alan V. Morgan ◽  
Anne Morgan

A 21-kg sample of plant detritus from the Two Creeks forest bed at the junction of Kewaunee and Manitowoc Counties, Wisconsin, has produced a small, but well-preserved fauna of Coleoptera, Hymenoptera, and Diptera. Among the Coleoptera the majority of Carabidae (ground beetles) indicate moderately moist to fairly dry, open ground conditions with a sparsely vegetated substrate. Another significant beetle group is represented by the Scolytidae (bark beetles) nearly all of which inhabit spruce. The restricted number of Coleoptera species (21) is believed to represent an in situ assemblage and is part of about 50 taxa. Most of the Coleoptera identified to the species level have a transcontinental distribution, with the exception of two carabids which are extreme western forms, and nearly all reside within the boreal forest. The beetles indicate that the mean July temperature at Two Creeks approximately 11,850 yr B.P. was 14° to 16°C.


2001 ◽  
Vol 38 (10) ◽  
pp. 1451-1462 ◽  
Author(s):  
John E Motz ◽  
Alan V Morgan

An unusually rich and extensive 5 m sequence of organic-rich sediments (ca. 13 000 to ca. 4500 BP) from a drained glacial kettle near Brampton, Ontario, has produced a large and varied assemblage of fossil insects. Coleoptera (beetles) from the base include species typical of northern boreal or tree line habitats today. Approximately one metre above the base of the section (ca. 11 500 BP), there is an abrupt appearance of numerous bark beetles (family Scolytidae) and other Coleoptera that inhabit boreal forests. Temperate species whose ranges are predominantly or totally south of the Ontario border, appear, beginning at ca. 9500 BP, suggesting environmental conditions similar to modern ones. Younger Dryas and Pre-Boreal Oscillation cold events may be evident in lower parts of the boreal sequence, although considerations of temporal and climatic resolution make interpretation somewhat ambiguous.


2018 ◽  
Vol 22 (1) ◽  
pp. 22
Author(s):  
Jayusman Jayusman ◽  
Muhammad Na’iem ◽  
Sapto Indrioko ◽  
Eko Bhakti Hardiyanto ◽  
ILG Nurcahyaningsih

Surian Toona sinensis Roem is one of the most widely planted species in Indonesia. This study aimed to estimate the genetic diversity between a number of surian populations in a progeny test using RAPD markers, with the goal of proposing management strategies for a surian breeding program. Ninety-six individual trees from 8 populations of surian were chosen as samples for analysis. Eleven polymorphic primers (OP-B3, OP-B4, OP-B10, OP-H3, OP-Y6, OP-Y7, OP-Y8, OP-Y10, OP-Y11, OP-Y14, and OP-06) producing reproducible bands were analyzed for the 96 trees, with six trees per family sampled. Data were analyzed using GenAlEx 6.3, NTSYS 2.02. The observed percentage of polymorphic loci ranged from 18.2% to 50%. The mean level of genetic diversity among the surian populations was considered to be moderate (He 0.304). Cluster analysis grouped the genotypes into two main clusters, at similarity levels of 0.68 and 0.46. The first two axes of the PCoA explained 46.16% and 25.54% of the total variation, respectively. The grouping of samples into clusters and subclusters did not correspond with family and their distances, but the grouping was in line with the genetic distances of the samples.


2016 ◽  
pp. 59-68
Author(s):  
Mara Tabaković-Tošić ◽  
Marija Milosavljević

The paper presents the results of the research on the correlation between changes in microclimate, the intensity of spruce decline and active abundance of its two economically most significant harmful insects-eight-toothed (Ips typographus) and six-toothed (Pityogenes chalcographus) spruce bark beetles (Coleoptera: Curculionidae) in Golija Nature Park whose pure and mixed conifer stands are dominated by spruce. The route method and ocular inspection were applied to study the presence and determine the intensity of spruce decline-both of individual trees and groups of trees in the management units of Dajićke planine, Kolješnica, Golija and Brusničke šume. Population dynamics of the two species of bark beetles and their active abundance were monitored by the method of trapping with barrier traps and the use of combined pheromone dispensers-PCIT Ecolure. Although the decline of individual conifer trees, primarily of spruce, had already been present in certain areas of these management units for several decades, it reached epidemic proportions due to extreme adverse climatic conditions in the period between 2011 and 2012 and culminated in 2015. A large number of physiologically weakened trees raised the population levels of secondary harmful insects and the number or the active abundance of the two investigated species of insects reached a peak in 2016. The inability to take appropriate and timely remedial measures in the areas under stricter protection regimes greatly contributed to this situation.


Author(s):  
Marilyn W. Walker ◽  
Mary E. Edwards

Historically the boreal forest has experienced major changes, and it remains a highly dynamic biome today. During cold phases of Quaternary climate cycles, forests were virtually absent from Alaska, and since the postglacial re-establishment of forests ca 13,000 years ago, there have been periods of both relative stability and rapid change (Chapter 5). Today, the Alaskan boreal forest appears to be on the brink of further significant change in composition and function triggered by recent changes that include climatic warming (Chapter 4). In this chapter, we summarize the major conclusions from earlier chapters as a basis for anticipating future trends. Alaska warmed rapidly at the end of the last glacial period, ca 15,000–13,000 years ago. Broadly speaking, climate was warmest and driest in the late glacial and early Holocene; subsequently, moisture increased, and the climate gradually cooled. These changes were associated with shifts in vegetation dominance from deciduous woodland and shrubland to white spruce and then to black spruce. The establishment of stands of fire-prone black spruce over large areas of the boreal forest 5000–6000 years ago is linked to an apparent increase in fire frequency, despite the climatic trend to cooler and moister conditions. This suggests that long-term features of the Holocene fire regime are more strongly driven by vegetation characteristics than directly by climate (Chapter 5). White spruce forests show decreased growth in response to recent warming, because warming-induced drought stress is more limiting to growth than is temperature per se (Chapters 5, 11). If these environmental controls persist, projections suggest that continued climate warming will lead to zero net annual growth and perhaps the movement of white spruce to cooler upland forest sites before the end of the twenty-first century. At the southern limit of the Alaskan boreal forest, spruce bark beetle outbreaks have decimated extensive areas of spruce forest, because warmer temperatures have reduced tree resistance to bark beetles and shortened the life cycle of the beetle from two years to one, shifting the tree-beetle interaction in favor of the insect (Chapter 9).


The Holocene ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 847-857 ◽  
Author(s):  
Nick Schafstall ◽  
Niina Kuosmanen ◽  
Christopher J Fettig ◽  
Miloš Knižek ◽  
Jennifer L Clear

Outbreaks of conifer bark beetles in Europe and North America have increased in scale and severity in recent decades. In this study, we identify existing fossil records containing bark beetle remains from the end of the Last Glacial Maximum (~14,000 cal. yr BP) to present day using the online databases Neotoma and BugsCEP and literature searches, and compare these data with modern distribution data of selected tree-killing species. Modern-day observational data from the Global Biodiversity Information Facility (GBIF) database was used to map recorded distributions from AD 1750 to present day. A total of 53 fossil sites containing bark beetle remains, from both geological and archeological sites, were found during our searches. Fossil sites were fewer in Europe ( n = 21) than North America ( n = 32). In Europe, 29% of the samples in which remains were found were younger than 1000 cal. yr BP, while in North America, remains were mainly identified from late Glacial (~14,000–11,500 cal. yr BP) sites. In total, the fossil records contained only 8 of 20 species we consider important tree-killing bark beetles in Europe and North America based on their impacts during the last 100 years. In Europe, Ips sexdentatus was absent from the fossil record. In North America, Dendroctonus adjunctus, Dendroctonus frontalis, Dendroctonus jeffreyi, Dendroctonus pseudotsugae, Dryocoetes confusus, Ips calligraphus, Ips confusus, Ips grandicollis, Ips lecontei, Ips paraconfusus, and Scolytus ventralis were absent. Overall, preserved remains of tree-killing bark beetles are rare in the fossil record. However, by retrieving bulk material from new and existing sites and combining data from identified bark beetle remains with pollen, charcoal, tree rings, and geochemistry, the occurrence and dominance of bark beetles, their outbreaks, and other disturbance events can be reconstructed.


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