The reduction of organic-layer depth by wildfire in the North American boreal forest and its effect on tree recruitment by seed

2007 ◽  
Vol 37 (6) ◽  
pp. 1012-1023 ◽  
Author(s):  
David F. Greene ◽  
S. Ellen Macdonald ◽  
Sybille Haeussler ◽  
Susy Domenicano ◽  
Josée Noël ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Inverse Function ◽  
Organic Layer ◽  
Layer Depth ◽  
Tree Recruitment ◽  
Organic Layers ◽  
Boreal Region ◽  
The North ◽  
Forest Species Composition

We compared prefire and postfire organic-layer depths in boreal forest types (14 fires) across Canada, and examined tree recruitment as a function of depth. There was extensive within-stand variation in depth, much of it due to clustering of thinner organic layers around boles. There were no significant differences in postfire organic-layer depth among sites with different prefire forest species composition, but sites in the eastern boreal region had thicker postfire organic layers than those in the western boreal region. Mean organic-layer depth was much greater in intact stands than after fires; overall, fire reduced organic-layer depth by 60%, largely because of increases in the area of thin (<3 cm) organic layers (1% in intact stands vs. 40% in postfire stands). There was more variation in organic-layer depth within postfire than within prefire stands; notably, some areas in postfire stands were deeply combusted, while adjacent parts were only lightly combusted. We speculate that the diminished role of energy loss to latent heat around tree boles increased organic-layer consumption around tree boles. Seedlings were clustered around burned tree bases, where organic layers were thinner, and the dependence of a species on thin organic layers was an inverse function of seed size.

Wounding of aspen roots promotes suckering

2004 ◽  
Vol 82 (3) ◽  
pp. 310-315 ◽  
Author(s):  
Erin C Fraser ◽  
Victor J Lieffers ◽  
Simon M Landhäusser
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Growing Season ◽  
Organic Layer ◽  
Trembling Aspen ◽  
Layer Depth ◽  
Injury Type ◽  
Organic Layers ◽  
Root Injury ◽  
Root Sucker

In early May, 1-m sections of trembling aspen (Populus tremuloides Michx.) roots in a forest cutblock were carefully exposed and examined for damage. Undamaged roots were subjected to one of three wounding treatments (scrape, sever, or uninjured control) and were then reburied to either the full normal organic layer depth or to one third of the normal depth. Following one growing season, the roots were reexposed and assessed for aspen sucker numbers and growth rates. Results indicate that injured roots produced suckers nearly twice as often as uninjured roots. Further, injured roots produced more suckers per root, and these suckers were taller and had greater leaf area. Roots buried under shallow organic layers also generated more suckers, regardless of injury type. The side of injury (distal or proximal) did not affect any of the measured variables. The present study suggests that moderate wounding of aspen roots increases initial sucker numbers and growth rates.Key words: trembling aspen, root sucker, root injury, regeneration.

BRYOPHYTE SUBFOSSILS OF A LATE-GLACIAL DEPOSIT FROM THE MISSOURI COTEAU, SASKATCHEWAN

1965 ◽  
Vol 43 (8) ◽  
pp. 947-953 ◽  
Author(s):  
B. de Vries ◽  
C. D. Bird
Keyword(s):  
Boreal Forest ◽  
Higher Plants ◽  
Late Glacial ◽  
Organic Layer ◽  
Middle Zone ◽  
Higher Plant ◽  
Glacial Deposit ◽  
Boreal Species ◽  
The North ◽  
Missouri Coteau

Bryophyte and associated macro-subfossils were recovered from a kettle located in prairie southwest of Moose Jaw in the Missouri Coteau of southern Saskatchewan. The higher plants were discussed in an earlier paper.Three samples taken from the organic layer gave C14 datings ranging from 11,650 ± 150 to 10,270 ± 150 B.P.Sixteen species and one variety of Musci were recovered. Eleven of these were found in the lowermost zone at a depth of 510–450 cm. This zone was composed of bryophytes and higher plants characteristic of a modern Picea forest. Fifteen bryophyte taxa were recovered from the middle zone at a depth of 450–290 cm. The macro-subfossils in this zone are typical of a present-day Populus–Picea forest. No bryophytes were found in the upper layer, 290–280 cm characterized by higher plant macro-subfossils and pollen typical of a modern Picea forest.All bryophytes recovered belong to present-day taxa; however, many of the boreal species are not now found in the region as the southern margin of the boreal forest is now 200 miles to the north.

Watershed Hydrology and Chemistry in the Alaskan Boreal Forest: The Central Role of Permafrost

2006 ◽  
Author(s):  
Larry D. Hinzman ◽  
Kevin C. Petrone
Keyword(s):  
Boreal Forest ◽  
Active Layer ◽  
Hydrological Processes ◽  
Organic Layer ◽  
Freezing And Thawing ◽  
Surface Soils ◽  
Near Surface ◽  
Organic Layers ◽  
Discontinuous Permafrost ◽  
Permafrost Soils

Hydrological processes exert strong control over biological and climatic processes in every ecosystem. They are particularly important in the boreal zone, where the average annual temperatures of the air and soil are relatively near the phase-change temperature of water (Chapter 4). Boreal hydrology is strongly controlled by processes related to freezing and thawing, particularly the presence or absence of permafrost. Flow in watersheds underlain by extensive permafrost is limited to the near-surface active layer and to small springs that connect the surface with the subpermafrost groundwater. Ice-rich permafrost, near the soil surface, impedes infiltration, resulting in soils that vary in moisture content from wet to saturated. Interior Alaska has a continental climate with relatively low precipitation (Chapter 4). Soils are typically aeolian or alluvial (Chapter 3). Consequently, in the absence of permafrost, infiltration is relatively high, yielding dry surface soils. In this way, discontinuous permafrost distribution magnifies the differences in soil moisture that might normally occur along topographic gradients. Hydrological processes in the boreal forest are unique due to highly organic soils with a porous organic mat on the surface, short thaw season, and warm summer and cold winter temperatures. The surface organic layer tends to be much thicker on north-facing slopes and in valley bottoms than on south-facing slopes and ridges, reflecting primarily the distribution of permafrost. Soils are cooler and wetter above permafrost, which retards decomposition, resulting in organic matter accumulation (Chapter 15). The markedly different material properties of the soil layers also influence hydrology. The highly porous near-surface soils allow rapid infiltration and, on hillsides, downslope drainage. The organic layer also has a relatively low thermal conductivity, resulting in slow thaw below thick organic layers. The thick organic layer limits the depth of thaw each summer to about 50–100 cm above permafrost (i.e., the active layer). As the active layer thaws, the hydraulic properties change. For example, the moisture-holding capacity increases, and additional subsurface layers become available for lateral flow. The mosaic of Alaskan vegetation depends not only on disturbance history (Chapter 7) but also on hydrology (Chapter 6).

Paludification dynamics in the boreal forest of the James Bay Lowlands: effect of time since fire and topography

2009 ◽  
Vol 39 (3) ◽  
pp. 546-552 ◽  
Author(s):  
Martin Simard ◽  
Pierre Y. Bernier ◽  
Yves Bergeron ◽  
David Paré ◽  
Lakhdar Guérine
Keyword(s):  
Organic Matter ◽  
Boreal Forest ◽  
Black Spruce ◽  
Forest Productivity ◽  
Organic Layer ◽  
Layer Depth ◽  
Potential Productivity ◽  
Organic Matter Accumulation ◽  
Soil Organic Layer ◽  
Time Since Fire

In many northern forest ecosystems, soil organic matter accumulation can lead to paludification and forest productivity losses. Paludification rate is primarily influenced by topography and time elapsed since fire, two factors whose influence is often confounded and whose discrimination would help forest management. This study, which was conducted in the black spruce ( Picea mariana (Mill.) BSP) boreal forest of northwestern Quebec (Canada), aimed to (1) quantify the effect of slope and time since fire on paludification rates, (2) determine whether soil organic layer depth could be estimated by surface variables that can potentially be remotely sensed, and (3) relate the degree of paludification to tree productivity. In this study, soil organic layer depth was used as an estimator of the degree of paludification. Slope and postfire age strongly affected paludification dynamics. Young stands growing on steep slopes had thinner organic layers and lower organic matter accumulation rates compared with young stands growing on flat sites. Black spruce basal area and Sphagnum cover were strong predictors of organic layer depth, potentially allowing mapping of paludification degree across the landscape. Tree productivity was negatively related to organic layer depth (R2 = 0.57). The equations developed here can be used to quantify forest productivity decline in stands that are undergoing paludification, as well as potential productivity recovery given appropriate site preparation techniques.

Does the post-fire organic layer compress beneath the snowpack?

2010 ◽  
Vol 19 (5) ◽  
pp. 673
Author(s):  
T. B. Splawinski ◽  
D. F. Greene ◽  
S. Gauthier ◽  
Y. Bergeron
Keyword(s):  
Boreal Forest ◽  
Positive Relationship ◽  
Seedling Recruitment ◽  
Organic Layer ◽  
Compression Rate ◽  
Initial Thickness ◽  
Layer Depth ◽  
Lower Porosity ◽  
Significant Compression ◽  
North Western

It is well known that post‐fire duff layers that are thin or of lower porosity greatly enhance juvenile survivorship of sexually recruiting boreal plant species. Nonetheless, there has been no study on duff compaction by snow following charring. We examined post‐fire duff depth for the first 3 years (two winters) after a 2006 wildfire in the boreal forest of north‐western Quebec. We found that (1) significant compression was common, with (2) a positive relationship between the initial thickness of the burned organic layer depth and the subsequent amount of compression. The proportional compression rate was, however, roughly constant: ∼14% after 2 years regardless of initial post‐fire duff depth. We conclude that this amount of compression is too little to significantly impact post‐fire seedling recruitment.

The Inherited Past of the Broch: On Antiquarian Discourse and Contemporary Archaeology

2002 ◽  
Vol 24 (1) ◽  
pp. 1-20 ◽  
Author(s):  
ANDREW BAINES
Keyword(s):  
Material Culture ◽  
19Th Century ◽  
Academic Language ◽  
Contemporary Archaeology ◽  
The North

In reading archaeological texts, we expect to be engaged in a characteristically archaeological discourse, with a specific and recognisable structure and vocabulary. In evaluating the published work of 19th Century antiquarians, we will inevitably look for points of contact between their academic language and our own; success or failure in the identification of such points of contact may prompt us to recognise a nascent archaeology in some writings, while dismissing others as naïve or absurd. With this point in mind, this paper discusses the written and material legacies of three 19th Century antiquarians in the north of Scotland who worked on a particular monument type, the broch. The paper explores the degree to which each has been admitted as an influence on the development of the broch as a type. It then proceeds to compare this established typology with the author's experiences, in the field, of the sites it describes. In doing so, the paper addresses wider issues concerning the role of earlier forms of archaeological discourse in the development of present day archaeological classifications of, and of the problems of reconciling such classifications with our experiences of material culture.

Training of Village Teachers in Vilna Educational District in the 1860s and 1870s

2020 ◽  
Vol 58 ◽  
pp. 181-192
Author(s):  
Anna A. Komzolova
Keyword(s):  
Educational Reform ◽  
Rural Teachers ◽  
Cultural Brokers ◽  
The North ◽  
Central Russia ◽  
Russian Intelligentsia ◽  
Trained Teachers ◽  
The Village ◽  
North Western

One of the results of the educational reform of the 1860s was the formation of the regular personnel of village teachers. In Vilna educational district the goal was not to invite teachers from central Russia, but to train them on the spot by establishing special seminaries. Trained teachers were supposed to perform the role of «cultural brokers» – the intermediaries between local peasants and the outside world, between the culture of Russian intelligentsia and the culture of the Belarusian people. The article examines how officials and teachers of Vilna educational district saw the role of rural teachers as «cultural brokers» in the context of the linguistic and cultural diversity of the North-Western Provinces. According to them, the graduates of the pedagogical seminaries had to remain within the peasant estate and to keep in touch with their folk «roots». The special «mission» of the village teachers was in promoting the ideas of «Russian elements» and historical proximity to Russia among Belarusian peasants.

Peranan Ombudsman Republik Indonesia Perwakilan Sumatera Utara Dalam Pengawasan Pelayanan Dinas Kependudukan dan Catatan Sipil Kota Medan

2019 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Putri Ananda Sari ◽  
Abdul Kadir ◽  
Beby Mashito Batu Bara
Keyword(s):  
Service Provider ◽  
Qualitative Approach ◽  
First Report ◽  
The North ◽  
Supervision Process ◽  
The Republic ◽  
North Sumatra

This study aims to determine the role of the Ombudsman of the Republic of Indonesia in North Sumatra Representative in the Supervision of Population and Civil Registry Service in Medan City. This study uses a qualitative approach with descriptive methods describing information about the data obtained from the field in the form of written and oral data from the parties studied. Data is collected based on interviews and documentation. The results of this study indicate that the role of the Ombudsman of the Republic of Indonesia in North Sumatra was carried out in the form of external supervision. External supervision is supervision carried out by the Ombudsman of the Republic of Indonesia Representative of North Sumatra to the Medan Population and Civil Registry Service. Actions taken in the supervision process are incoming reports, follow-up of the first report and follow-up of the report. Based on the research that has been carried out, it has been concluded that the role of the Ombudsman of the Republic of Indonesia in the North Sumatra Representative in supervising the service provider of the Population and Civil Registry services is carried out in the form of external supervision. In supervising the handling of public reports of alleged poor service in the area of population administration, it has been effective, with several efforts to handle reports such as: (1) Clarification; (2) Investigation; (3) Recommendations; (4) Monitoring.

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