Forest landscape change in the northwestern Wisconsin Pine Barrens from pre-European settlement to the present

1999 ◽  
Vol 29 (11) ◽  
pp. 1649-1659 ◽  
Author(s):  
Volker C Radeloff ◽  
David J Mladenoff ◽  
Hong S He ◽  
Mark S Boyce
Keyword(s):  
Populus Tremuloides ◽  
Vegetation Cover ◽  
Pinus Banksiana ◽  
Forest Cover ◽  
Natural Disturbance ◽  
Pine Barrens ◽  
Data Set ◽  
Forest Density ◽  
The North ◽  
European Settlement

Natural disturbance patterns can provide useful information for ecosystem management. Our objective was to provide a detailed spatial picture of the pre-European settlement vegetation cover for the northwestern Wisconsin Pine Barrens and to compare it with the present vegetation cover. We analyzed the presettlement conditions using an extensive data set comprised of U.S. General Land Office surveyor records from the mid-19th century and related it to the vegetation cover in 1987 as depicted in a Landsat satellite forest classification. Changes were quantified by calculating differences in abundance and relative importance of tree species at presettlement time and today. Our results revealed a strong decline of jack, red, and white pine (Pinus banksiana Lamb., Pinus resinosa Ait., and Pinus strobus L., respectively), accompanied by an increase of oak (Quercus spp.), trembling aspen (Populus tremuloides Michx.), and other hardwood species. Certain vegetation types, e.g., red pine and oak savannas, were removed from the landscape. The forest density gradient of the presettlement landscape with open savannas and woodlands in the South and denser forests in the North disappeared. These changes, especially the increase in forest cover, are ecologically significant because numerous species are adapted to open habitat, which was previously created by fire, and their populations are declining.

Adapting forestry practices to address old-growth concerns in the Great Lakes–St.Lawrence forests of Ontario

2003 ◽  
Vol 79 (3) ◽  
pp. 613-620 ◽  
Author(s):  
Fred Pinto
Keyword(s):  
Great Lakes ◽  
Populus Tremuloides ◽  
Pinus Banksiana ◽  
Natural Disturbance ◽  
Red Pine ◽  
Forest Composition ◽  
White Birch ◽  
Site Factors ◽  
Old Growth ◽  
Old Growth Forests

The Great Lakes–St. Lawrence forest, particularly the eastern white (Pinus strobus L.) and red pine (P. resinosa Ait.) forests around Temagami and Sault Ste. Marie, was the centre of controversy regarding the treatment of old-growth forests in Ontario in the 1980s and 1990s. The controversy stemmed from changes in forest composition and structure occurring in the forest. For example, the Ontario public was concerned with the obvious reduction in numbers of large eastern white and red pine trees and their replacement with small, often poor quality, white birch (Betula papyrifera Marsh.), aspen (Populus tremuloides Michx.), and jack pine (Pinus banksiana Lamb.) trees. Over the past two decades, changes in legislation, forest planning and stand prescriptions have been made in Ontario and practices at the forest and stand levels have also changed significantly. The new practices are based on linking forest activities to a better understanding of ecological processes in the forest; in particular, linking harvest and regeneration activities to our current understanding of natural disturbances and plant adaptations. These practices attempt to match more closely the conditions found in forests with a heritage of natural disturbance and reproduction, i.e., old-growth forests. For example, stand-initiating disturbances result in some trees being killed, some being damaged, and some surviving. The new harvest practices consider tree adaptations and site factors when deciding whether a tree will be cut or not. This paper provides examples of how this ecosystem-based forestry is being applied in Ontario. Key words: old growth in Ontario, conservation of old growth, application of old growth conservation practices, stand practices for old growth, landscape practices for old growth

Dendrochronological reconstruction of forest tent caterpillar outbreaks in time and space, western Manitoba, Canada

2007 ◽  
Vol 37 (9) ◽  
pp. 1643-1657 ◽  
Author(s):  
Alanna Sutton ◽  
Jacques C. Tardif
Keyword(s):  
20Th Century ◽  
Tree Ring ◽  
Populus Tremuloides ◽  
Pinus Banksiana ◽  
Large Scale ◽  
Growth Suppression ◽  
Forest Tent Caterpillar ◽  
Mixed Stands ◽  
The North ◽  
Tent Caterpillar

A tree-ring reconstruction of forest tent caterpillar ( Malacosoma disstria Hubner) outbreaks was conducted in the Duck Mountain Provincial Forest. Trembling aspen ( Populus tremuloides Michx.), balsam poplar ( Populus balsamifera L.), and paper birch ( Betula papyrifera Marsh.) tree-ring chronologies were used to identify periods of outbreaks from approximately 1800 to 2002. The impacts of the major forest tent caterpillar outbreaks of the 20th century were compared among four stand types and two age classes. The presence of white rings and growth suppression were used to identify three important outbreak periods, 1939–1948, 1961–1965, and 1982–1985, with another large-scale outbreak suspected during the 1870s. A roughly 20-year interval was observed between major outbreaks. Few differences were found between stand types, except during the 1960s, when mixed stands with jack pine ( Pinus banksiana Lamb.) registered more growth suppression and white rings. In general, the outbreak signal in the younger sites was variable. The importance of utilizing white rings and growth suppression data together is discussed. The major outbreaks of the 20th century generally started in the north of the Duck Mountain Provincial Forest. The technique was successful at identifying forest tent caterpillar outbreaks during the 20th and late 19th centuries, when no historical surveys were available.

Vegetation structure of tundra and taiga on the map of the natural vegetation of Europe

2007 ◽  
pp. 13-22 ◽  
Author(s):  
T. K. Yurkovskaya
Keyword(s):  
Vegetation Cover ◽  
Abiotic Factors ◽  
Self Regulation ◽  
Space Structure ◽  
Middle Taiga ◽  
Russian Plain ◽  
Forest Communities ◽  
The North ◽  
Tundra Vegetation ◽  
Starting Point

I have focused only on some features of structure in the taiga vegetation cover. In conclusion I would like to tell some words about the causes of complicated space structure of the taiga and tundra vegetation cover. The causes of latitudinal differentiation are climatic undoubtedly, but heterogeneity of vegetation cover within the limits of tundra and taiga subzones is accounted for different factors. In tundra abiogenic factors prevail, first of all the permafrost processes. That is the reason why tundra vegetation cover is so sensible to any disturbances and so hard regenerates after various transformations. In taiga the space structure is mostly the result of self-regulation and self- restoration of biota. The abiotic factors, certainly, play significant role, but they recede to the second plan. So we showed that in the north and middle taiga the structure of vegetation cover, during the Holocene up to present time, is determined in many respects by the increasing role of mires. Suffice it to look at the map of distribution of mires in order to estimate their role in vegetation cover of the easteuropean taiga (Yurkovskaya, 1980). So, the increase of mire area on the Russian Plain in m2/year per 1000 ha varies between 200 and 700, the average increas is ca 300—400 m2/year (Elina et all., 2000). The mires favour peniplenization and unite the separate areas of forest communities into the whole by means of forming the buffer paludificated territories (various hydrophilous variants of forest communities). But if mires, at all their stability, after destroying practically don't restore, the forests even after continuous cuttings restore their structure and composition through the series of successional stages unless an ecotope is damaged completely. Hence the space structure of taiga is the result, first of all, self development and self regulation of its vegetation cover. But, as it is known, at present time the process of destruction of natural biota has gone too far that the question arises not only about supporting its state and structure but also about the survival of the mankind itself. In this regard the vegetation map of Europe is the invaluable basis, which gives the starting point for all conservational, ecological and economical measures. But it is important to learn reading and using the map. And this is one of our actual goals.

scholarly journals Regional differences in the evolution of the merger of /ʃ/ and /ç/ in Luxembourgish

2021 ◽  
pp. 1-18
Author(s):  
François Conrad
Keyword(s):  
Language Contact ◽  
Sound Change ◽  
Young Generation ◽  
The South ◽  
Data Set ◽  
West Germanic ◽  
The North ◽  
Minimal Pairs ◽  
Old Men ◽  
Middle Generation

The merger of post-alveolar /ʃ/ and palatal /ç/ into alveolopalatal /ɕ/ has recently gained growing interest in sociophonetic research, especially in the Middle German dialect area. In Luxembourgish, a Continental West Germanic language, the sound change has been linked to age differences, while its origins remain unclear. Two studies with a regional focus are presented in this paper. The first study examines the merger in the Centre and the South of Luxembourg. The acoustic examination of both the spectral peak and the centre of gravity of a spoken data set of five minimal pairs embedded in read and orally translated sentences from 48 speakers (three generations (old generation, 65–91 years; middle generation, 40–64 years; young generation, 20–39 years; each generation, n = 16), men and women) reveals interesting results related to their regional background. In the old generation, the merger is further advanced in the speech of old men from the former mining region in the South compared to their peers in the Centre, the former leading this sound change. On the other hand, young speakers in both regions produce only alveolopalatal /ɕ/, the merger being complete in this generation. The second study presents exploratory data from the East and the North of the country. The analysis of this smaller sample (n = 6 speakers) reveals patterns similar to the central region. Pointing to language contact with Romance in the South as cradle and/or catalyser of the merger, these results not only give further clues as to the development in Luxembourg, but also add to a deeper understanding of sound changes in process in complex sibilant systems.

Stochastic inversion of pressure and saturation changes from time-lapse AVO data

Geophysics ◽  
2006 ◽  
Vol 71 (5) ◽  
pp. C81-C92 ◽  
Author(s):  
Helene Hafslund Veire ◽  
Hilde Grude Borgos ◽  
Martin Landrø
Keyword(s):  
Stochastic Model ◽  
Seismic Data ◽  
Synthetic Data ◽  
Time Lapse ◽  
Bayesian Framework ◽  
Reservoir Modeling ◽  
Data Set ◽  
The North ◽  
Fluid Saturation ◽  
Likelihood Model

Effects of pressure and fluid saturation can have the same degree of impact on seismic amplitudes and differential traveltimes in the reservoir interval; thus, they are often inseparable by analysis of a single stacked seismic data set. In such cases, time-lapse AVO analysis offers an opportunity to discriminate between the two effects. We quantify the uncertainty in estimations to utilize information about pressure- and saturation-related changes in reservoir modeling and simulation. One way of analyzing uncertainties is to formulate the problem in a Bayesian framework. Here, the solution of the problem will be represented by a probability density function (PDF), providing estimations of uncertainties as well as direct estimations of the properties. A stochastic model for estimation of pressure and saturation changes from time-lapse seismic AVO data is investigated within a Bayesian framework. Well-known rock physical relationships are used to set up a prior stochastic model. PP reflection coefficient differences are used to establish a likelihood model for linking reservoir variables and time-lapse seismic data. The methodology incorporates correlation between different variables of the model as well as spatial dependencies for each of the variables. In addition, information about possible bottlenecks causing large uncertainties in the estimations can be identified through sensitivity analysis of the system. The method has been tested on 1D synthetic data and on field time-lapse seismic AVO data from the Gullfaks Field in the North Sea.

Effects of commercial thinning on site occupancy and habitat use by spruce grouse in boreal Quebec

2011 ◽  
Vol 41 (3) ◽  
pp. 501-508 ◽  
Author(s):  
Ambroise Lycke ◽  
Louis Imbeau ◽  
Pierre Drapeau
Keyword(s):  
Habitat Use ◽  
Boreal Forest ◽  
Breeding Season ◽  
Vegetation Cover ◽  
Forest Cover ◽  
Site Occupancy ◽  
Lower Proportion ◽  
Large Mammals ◽  
Dense Vegetation ◽  
Commercial Thinning

Partial cuts are increasingly proposed to maintain habitats for species negatively affected by clearcutting, even if their benefits on nonpasserine birds and large mammals are still poorly documented. Our main objective was to evaluate effects of commercial thinning (CT) on spruce grouse ( Falcipennis canadensis L.), a game bird of the boreal forest. Because this species is known to be associated with a dense vegetation cover, we hypothesized that habitat use would be lower in treated sites. In spring 2006, we evaluated site occupancy in 94 forest stands (50 CT and 44 uncut stands) in Quebec by visiting each on three occasions during the breeding season (March–May). Additionally, during the molting period (May–July), we used radiotelemetry to monitor habitat use by 19 males. As compared with uncut stands, results show that a lower proportion of CTs were used in spring (39% versus 60%, after accounting for detection). During the molting period, CTs were also used less than expected according to their availability. The significant reduction of lateral and vertical forest cover in CT may explain these results. We conclude that even if CT is perceived beneficial for wildlife, it does not completely fulfill the needs of species associated with dense understory vegetation, such as spruce grouse.

Catastrophic disturbance in the presettlement forests of the Upper Peninsula of Michigan

1999 ◽  
Vol 29 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Quanfa Zhang ◽  
Kurt S Pregitzer ◽  
David D Reed
Keyword(s):  
Forest Cover ◽  
Vegetation Type ◽  
Natural Disturbance ◽  
Growth Stages ◽  
Mosaic Landscape ◽  
Upper Peninsula ◽  
Rotation Periods ◽  
General Land Office ◽  
Ecological Unit ◽  
Upper Peninsula Of Michigan

The General Land Office (GLO) survey notes (1840-1856) were used to examine the interaction among natural disturbance, vegetation type, and topography in the presettlement forests of the Luce District, an ecological unit of approximately 902 000 ha in the Upper Peninsula of Michigan, U.S.A. The surveyors recorded 104 fire and 126 windthrow incidences covering 3.1 and 2.8% of the total length of the surveyed lines, respectively. The rotation periods over the entire landscape were 480 years for fire and 541 years for windthrow, but these varied with vegetation type and topographic position. Fire occurred more frequently on southerly aspects and at elevations where pinelands were concentrated. The density of windthrow events increased with elevation and slope, with the highest occurrence on westerly aspects. Based on the estimated rotation periods, we calculated that 7.5, 24.4, and 68.1% of the presettlement forest were in the stand initiation, stem exclusion, and old forest (including both understory reinitiation and old growth) stages, respectively. Pinelands and mixed conifers were the major components in both the stand initiation (34.5 and 31.1%) and the stem exclusion stage (20.9 and 39.8%), while mixed conifers (39.3%) and northern hardwoods (34.7%) were the major old-forest cover types. The diverse mosaic of various successional stages generated by natural disturbance suggests a "shifting-mosaic" landscape in this region.

scholarly journals Global estimation of burned area using MODIS active fire observations

2006 ◽  
Vol 6 (4) ◽  
pp. 957-974 ◽  
Author(s):  
L. Giglio ◽  
G. R. van der Werf ◽  
J. T. Randerson ◽  
G. J. Collatz ◽  
P. Kasibhatla
Keyword(s):  
Vegetation Cover ◽  
Regression Trees ◽  
The United States ◽  
Tree Cover ◽  
Burned Area ◽  
Data Set ◽  
Active Fire ◽  
Terra Modis ◽  
Good Agreement ◽  
Area Data

Abstract. We present a method for estimating monthly burned area globally at 1° spatial resolution using Terra MODIS data and ancillary vegetation cover information. Using regression trees constructed for 14 different global regions, MODIS active fire observations were calibrated to burned area estimates derived from 500-m MODIS imagery based on the assumption that burned area is proportional to counts of fire pixels. Unlike earlier methods, we allow the constant of proportionality to vary as a function of tree and herbaceous vegetation cover, and the mean size of monthly cumulative fire-pixel clusters. In areas undergoing active deforestation, we implemented a subsequent correction based on tree cover information and a simple measure of fire persistence. Regions showing good agreement between predicted and observed burned area included Boreal Asia, Central Asia, Europe, and Temperate North America, where the estimates produced by the regression trees were relatively accurate and precise. Poorest agreement was found for southern-hemisphere South America, where predicted values of burned area are both inaccurate and imprecise; this is most likely a consequence of multiple factors that include extremely persistent cloud cover, and lower quality of the 500-m burned area maps used for calibration. Application of our approach to the nine remaining regions yielded comparatively accurate, but less precise, estimates of monthly burned area. We applied the regional regression trees to the entire archive of Terra MODIS fire data to produce a monthly global burned area data set spanning late 2000 through mid-2005. Annual totals derived from this approach showed good agreement with independent annual estimates available for nine Canadian provinces, the United States, and Russia. With our data set we estimate the global annual burned area for the years 2001-2004 to vary between 2.97 million and 3.74 million km2, with the maximum occurring in 2001. These coarse-resolution burned area estimates may serve as a useful interim product until long-term burned area data sets from multiple sensors and retrieval approaches become available.

Velocity changes across the Ganos segment of the North Anatolian Fault Zone in NW Turkey from systematic variations in body wave arrival times

2021 ◽  
Author(s):  
Esref Yalcinkaya ◽  
Marco Bohnhoff ◽  
Patricia Martinez-Garzon ◽  
Ethem Görgün ◽  
Ali Pınar ◽  
...  
Keyword(s):  
Body Wave ◽  
Waveform Analysis ◽  
Marmara Region ◽  
Rupture Directivity ◽  
Data Set ◽  
High Resolution Data ◽  
Arrival Times ◽  
The North ◽  
Nw Turkey ◽  
Geological Units

<p>Imaging and characterizing transform fault sections that are capable to produce large earthquakes is crucial for evaluating seismic hazard and subsequent risk for nearby population centers. The Marmara Fault near the megacity of Istanbul is one of the best defined seismic gaps in the world and its complexity is captured by seismological, geodetic and geological data. A local dense seismic array (MONGAN) provides a high resolution data set allowing to image the Ganos fault separating two different geological units in the western Marmara region. First results of the waveform analysis from this array present systematic early-phase arrivals at the seismic stations located on the northern block of the Ganos fault which comprises geological units including older and more compact materials than that of the southern block. This difference in the arrival times causes the earthquake epicenters to shift further north than the real locations. In this preliminary results, the early-arrivals will be evaluated according to source azimuths and distances, and possible earth models and wave paths will be discussed. The results have implications for rupture directivity during future earthquakes as input for hazard and risk models for the Marmara region.</p>

scholarly journals Transport and storage of anthropogenic C in the North Atlantic Subpolar Ocean

2018 ◽  
Vol 15 (14) ◽  
pp. 4661-4682 ◽  
Author(s):  
Virginie Racapé ◽  
Patricia Zunino ◽  
Herlé Mercier ◽  
Pascale Lherminier ◽  
Laurent Bopp ◽  
...  
Keyword(s):  
Interannual Variability ◽  
North Atlantic ◽  
General Circulation ◽  
Meridional Overturning Circulation ◽  
Intermediate Water ◽  
Data Set ◽  
The North ◽  
Storage Rate ◽  
The North Atlantic ◽  
And Storage

Abstract. The North Atlantic Ocean is a major sink region for atmospheric CO2 and contributes to the storage of anthropogenic carbon (Cant). While there is general agreement that the intensity of the meridional overturning circulation (MOC) modulates uptake, transport and storage of Cant in the North Atlantic Subpolar Ocean, processes controlling their recent variability and evolution over the 21st century remain uncertain. This study investigates the relationship between transport, air–sea flux and storage rate of Cant in the North Atlantic Subpolar Ocean over the past 53 years. Its relies on the combined analysis of a multiannual in situ data set and outputs from a global biogeochemical ocean general circulation model (NEMO–PISCES) at 1∕2∘ spatial resolution forced by an atmospheric reanalysis. Despite an underestimation of Cant transport and an overestimation of anthropogenic air–sea CO2 flux in the model, the interannual variability of the regional Cant storage rate and its driving processes were well simulated by the model. Analysis of the multi-decadal simulation revealed that the MOC intensity variability was the major driver of the Cant transport variability at 25 and 36∘ N, but not at OVIDE. At the subpolar OVIDE section, the interannual variability of Cant transport was controlled by the accumulation of Cant in the MOC upper limb. At multi-decadal timescales, long-term changes in the North Atlantic storage rate of Cant were driven by the increase in air–sea fluxes of anthropogenic CO2. North Atlantic Central Water played a key role for storing Cant in the upper layer of the subtropical region and for supplying Cant to Intermediate Water and North Atlantic Deep Water. The transfer of Cant from surface to deep waters occurred mainly north of the OVIDE section. Most of the Cant transferred to the deep ocean was stored in the subpolar region, while the remainder was exported to the subtropical gyre within the lower MOC.

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