Vegetation development on reclaimed lands in the Coal Valley Mine of western Alberta, Canada

2000 ◽  
Vol 78 (1) ◽  
pp. 110-118 ◽  
Author(s):  
W L Strong

Revegetated lands within the Coal Valley Mine were sampled for species composition, woody plant frequencies, and tree heights. The vegetation on 68 sampled sites was dominated by a mixture of Festuca rubra L. and Trifolium repens L. Four distinctive plant communities were present. A Lodgepole pine/Willow/Lindley's aster community represented the most advanced stage of forest development, having a multilayered structure and composed primarily of indigenous species, although only 19 years old. Deciduous shrubs and trees (<50 cm tall) occurred on 43% of the sites (mean 364 plants/ha). Salicaceae were the primary species. Total plant cover averaged >85% in all community types with plant litter covering >75% of the ground surface. There were 123 plant species found growing on the mine with 77% indigenous species, although they represented <5% of the total vegetation cover. The height of planted Pinus contorta Loudon and Picea glauca (Moench) Voss were modelled over a 24-year period. Both species had reduced height growth and significant attrition for several years after planting. On average, however, surviving trees had 8- and 14-year heights similar to local provincial reforestation standards. It is hypothesized that tree canopy closure is a key factor in facilitating the naturalization of forest understory vegetation on reclaimed lands.Key words: succession, plant community development, afforestation, perturbation.

Author(s):  
М. А. Babaeva ◽  
S. V. Osipova

The regularities of changes in the resistance of different groups of fodder plants to adverse conditions were studied. This is due to the physiological properties that allow them to overcome the harmful effects of the environment. As a result of research species - plant groups with great adaptive potential to the harsh continental semi-desert conditions were identified. Monitoring observation and experimental studies showed too thin vegetation cover as a mosaic, consisting of perennial xerophytic herbs and semishrubs, sod grasses, saltwort and wormwood, as well as ephemera and ephemeroids under the same environmental conditions, depending on various climatic and anthropogenic factors. This is due to the inability or instability of plant species to aggressive living environment. It results in horizontal heterogeneity of the grass stand, division into smaller structures, and mosaic in the vegetation cover of the Kochubey biosphere station. The relative resistance to moderate stress was identified in the following species from fodder plants Agropyron cristatum, A. desertorum, Festuca valesiaca, Cynodon dactylon, Avena fatua; as for strong increasing their abundance these are poorly eaten plant species Artemisia taurica, Atriplex tatarica, Falcaria vulgaris, Veronica arvensis, Arabidopsis thaliana and other. On the site with an increasing pressure in the herbage of phytocenoses the number of xerophytes of ruderal species increases and the spatial structure of the vegetation cover is simplified. In plant communities indigenous species are replaced by adventive plant species. The mosaic of the plant cover of phytocenoses arises due to the uneven distribution in the space of environmental formation, i.e. an edificatory: Salsola orientalis, S. dendroides, Avena fatua, Cynodon dactylon, Artemisia taurica, A. lercheanum, Xanthium spinosum, Carex pachystyli, under which the remaining components of the community adapt. Based on the phytocenotic indicators of pasture phytocenoses it can be concluded that the vegetation cover is in the stage of ecological stress and a decrease in the share of fodder crops and an increase in the number of herbs indicates this fact.


Koedoe ◽  
2006 ◽  
Vol 49 (1) ◽  
Author(s):  
M. Van Deventer ◽  
J.A.J. Nel

The effect of habitat differences and food availability on small mammal (rodent and elephant shrew) species richness, diversity, density and biomass was investigated in Namaqualand, South Africa. Species richness in the three habitats sampled, namely Upland Succulent Karoo, Dry Riverine Shrub and North-western Mountain Renosterveld was low, with only 2–4 species per habitat. Rodents trapped were predominantly Gerbillurus paeba and Aethomys namaquensis, with fewer Mus minutoides and Petromyscus sp. The only non-rodent was the elephant shrew Elephantulus edwardii. Ten habitat features, the percentage of total plant cover, tree cover, shrub cover, grass cover, plant litter, total basal cover, sand, gravel or rock cover, and the dominant plant height were recorded at 30 randomly chosen points on five sampling grids in each habitat. Small mammal density and biomass was significantly correlated with food availability (green foliage cover, seeds, and relative density and biomass of insects). Species richness and diversity of small mammals were significantly correlated with shrub cover. Numbers and biomass of specific species correlated significantly with different habitat features in each case.


2010 ◽  
Vol 86 (1) ◽  
pp. 118-129 ◽  
Author(s):  
M J Waterhouse ◽  
E. C. Wallich ◽  
N. M. Daintith ◽  
H. M. Armleder

Mature lodgepole pine (Pinus contorta) forests were harvested using group selection (GS) (0.02-ha openings) and irregular group shelterwood (IGS) (0.05-ha openings) systems to maintain arboreal and terrestrial lichens in the winter range of northern woodland caribou (Rangifer tarandus caribou). Ten years after planting, lodgepole pine showed excellent survival, but were smaller in the partial cut openings compared to the clearcuts. Pine grew less in the Sub-Boreal Pine–Spruce biogeoclimatic subzone (SBPSxc) than in the Montane Spruce subzone (MSxv), and trees were smaller in the GS versus IGS treatment within the MSxv subzone. Interior spruce (Picea glauca × engelmannii) grew best in the MSxv and partial cut treatments, but was significantly affected by summer frost in the clearcuts. In an operational-scale Adaptive Management trial, openings were enlarged to 0.15 ha, and both pine and spruce showed excellent survival, minimal frost damage, and 10-year size similar to clearcut conditions. This study suggests that lodgepole pine and interior spruce can be successfully regenerated in partial cut openings with acceptable growth in gaps of 0.15 ha. Key words: caribou, group selection, interior spruce, irregular group shelterwood, light level, lodgepole pine, Montane Spruce zone, partial harvest, soil moisture, soil temperature, Sub-Boreal Pine Spruce zone, summer frost


Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 315 ◽  
Author(s):  
Erik A. Lehnhoff ◽  
Lisa J. Rew ◽  
Jane M. Mangold ◽  
Tim Seipel ◽  
Devon Ragen

Cheatgrass (Bromus tectorum L.) is one of the most problematic weeds in western United States rangelands and sagebrush steppe. It responds positively to different forms of disturbance, and its management has proven difficult. Herbicide or targeted grazing alone often fail to provide adequate long-term control. Integrating both may afford better control by providing multiple stressors to the weed. We assessed herbicide application, targeted sheep grazing and integrated herbicide and grazing on B. tectorum and the plant community in rangeland in southwestern Montana from 2015 until 2017. Herbicide treatments included spring-applied (May 2015 and 2016) glyphosate, fall-applied (October 2015) glyphosate, imazapic and rimsulfuron, and spring-applied glyphosate plus fall-applied imazapic. Targeted grazing, consisting of four sheep/0.01 ha for a day in 5 m × 20 m plots (all vegetation removed to the ground surface), occurred twice (May 2015 and 2016). While no treatments reduced B. tectorum biomass or seed production, grazing integrated with fall-applied imazapic or rimsulfuron reduced B. tectorum cover from approximately 26% to 14% in 2016 and from 33% to 16% in 2017, compared to ungrazed control plots, and by an even greater amount compared to these herbicides applied without grazing. By 2017, all treatments except spring-applied glyphosate increased total plant cover (excluding B. tectorum) by 8%–12% compared to the control plots, and forbs were generally responsible for this increase. Bromus tectorum management is difficult and our results point to a potential management paradox: Integrating grazing and fall-applied herbicide decreased B. tectorum cover but did not increase native grass cover, while some herbicides without grazing increased native grass cover, but failed to control B. tectorum. Additional research is necessary to determine grazing strategies that will complement herbicide control of B. tectorum while also stimulating native grass recovery, but this initial study demonstrates the potential of integrated management of B. tectorum compared to grazing or herbicide alone.


1991 ◽  
Vol 6 (3) ◽  
pp. 64-67 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Wayne L. Martin

Abstract The incidence of meadow vole (Microtus pennsylvanicus) and brown lemming (Lemmus sibiricus) feeding damage to young plantations of lodgepole pine (Pinus contorta var. latifolia) and interior spruce (Picea glauca × Picea engelmannii) was studied in west-central British Columbia. Fifty-eight plantations were surveyed for seedling survival and stocking, and an additional 21 older plantations of lodgepole pine were surveyed for tree damage. Average survival of pine (47.7%) was significantly lower than that of spruce (56.0%). Because of mortality from vole feeding, 24 of the 58 plantations were not satisfactorily restocked. Planted trees were attacked significantly more than natural regeneration. Severely attacked plantations occurred in the spruce-subalpine fir (Abies lasiocarpa) forest type at elevations > 800 m on N to NE aspects. Susceptible plantations generally had mechanical or no site preparation with complex post-harvest debris and limited vegetation cover. West. J. Appl. For. 6(3):64-67.


1986 ◽  
Vol 62 (4) ◽  
pp. 226-232 ◽  
Author(s):  
R. F. Sutton

In mid-June 1978, hexazinone Gridball™ pellets were individually placed on the ground surface in two10-m × 10-m plots at each of two grid spacings in moderate-to-dense, woody weed growth in each of three boreal mixedwood stands in the Chapleau and Manitouwadge areas of Ontario. The rates of application were equivalent to 0.0, 1.4 and 4.2 kg a.i./ha. In these and a similar number of untreated plots, 16 white spruce (Picea glauca [Moench] Voss) were planted centrally in each plot at the same grid spacings used for the Gridballs™ but offset so as to give maximum separation between outplants and herbicide. The main study was supplemented by another to determine safe separation distance. GridballsTM at close spacing very significantly (P 0.01) increased growth of white spruce: at one location, the mean stem volume of spruce 7 years after planting was 438% that of spruce in the no-herbicide treatment; at a second location the comparable value was 503%. The evidence suggests that white spruce may be established in the boreal mixedwoods by underplanting and, concurrently, applying Gridballs™ at 1-m × 1-m spacing.


2005 ◽  
Vol 81 (4) ◽  
pp. 575-581 ◽  
Author(s):  
Oscar Garcia

Growth and yield predictions for managed even-aged stands in British Columbia are based on TASS, an individual-tree distance-dependent growth model driven by an unusually detailed description of crown development. Because of its complexity, most applications utilize previously generated stand-level yield tables rather than running TASS directly. I have developed a differential equation approximation to the stand-level dynamics predicted by TASS that mimics the aggregate behaviour with sufficient accuracy for many practical purposes. Versions of this model, called TADAM, exist for planted coastal Douglas-fir, lodgepole pine, and white spruce. TADAM can efficiently project stand development starting from any initial conditions, and subject to any combination of thinnings. Its relative simplicity makes it suitable for embedding into landscape-level planning models and other decision support systems. It has been implemented as a C function library, as an interactive simulator running on a PDA, and as an Excel spreadsheet add-in. An example of thinning and planting density optimization is briefly described. Key words: growth and yield, stand dynamics, thinning, optimization, Pinus contorta, Picea glauca


2019 ◽  
Vol 11 (3) ◽  
pp. 308 ◽  
Author(s):  
Donato Morresi ◽  
Alessandro Vitali ◽  
Carlo Urbinati ◽  
Matteo Garbarino

Understanding post-fire regeneration dynamics is an important task for assessing the resilience of forests and to adequately guide post-disturbance management. The main goal of this research was to compare the ability of different Landsat-derived spectral vegetation indices (SVIs) to track post-fire recovery occurring in burned forests of the central Apennines (Italy) at different development stages. Normalized Difference Vegetation Index (NDVI), Normalized Difference Moisture Index (NDMI), Normalized Burn Ratio (NBR), Normalized Burn Ratio 2 (NBR2) and a novel index called Forest Recovery Index 2 (FRI2) were used to compute post-fire recovery metrics throughout 11 years (2008–2018). FRI2 achieved the highest significant correlation (Pearson’s r = 0.72) with tree canopy cover estimated by field sampling (year 2017). The Theil–Sen slope estimator of linear regression was employed to assess the rate of change and the direction of SVIs recovery metrics over time (2010–2018) and the Mann–Kendall test was used to evaluate the significance of the spectral trends. NDVI displayed the highest amount of recovered pixels (38%) after 11 years since fire occurrence, whereas the mean value of NDMI, NBR, NBR2, and FRI2 was about 27%. NDVI was more suitable for tracking early stages of the secondary succession, suggesting greater sensitivity toward non-arboreal vegetation development. Predicted spectral recovery timespans based on pixels with a statistically significant monotonic trend did not highlight noticeable differences among normalized SVIs, suggesting similar suitability for monitoring early to mid-stages of post-fire forest succession. FRI2 achieved reliable results in mid- to long-term forest recovery as it produced up to 50% longer periods of spectral recovery compared to normalized SVIs. Further research is needed to understand this modeling approach at advanced stages of post-fire forest recovery.


2005 ◽  
Vol 83 (6) ◽  
pp. 638-646 ◽  
Author(s):  
J M Kranabetter

The possible benefit of common mycorrhizal network linkages to seedling growth was tested in a low light partial-cut forest understory. Naturally regenerated western hemlock (Tsuga heterophylla Raf.) and hybrid spruce (Picea glauca × Picea sitchensis [Moench] Voss) seedlings were transplanted directly into soil or within bags of different pore sizes to restrict the amounts of root and ectomycorrhizal contact. The 5-year study included "full contact" (no bag), "moderate contact" (250-µm openings), and "low contact" (4-µm openings) treatments. Height increment was lowest for full contact seedlings over most of the experiment, and highest for low contact seedlings by years 4 and 5. Full contact seedlings also had slightly lower foliar N content than moderate and low contact seedlings. There were no significant interactions in growth detected between tree species and treatments, despite the higher potential for common mycorrhizal network linkages between a western hemlock understory and canopy. Fifty-eight ectomycorrhizal fungal morphotypes were identified on the seedlings, including many with smooth mantles or with only sparse emanating hyphae, which likely reduced the potential for common mycorrhizal network linkages. These results would support the more traditional concepts of competition for scarce resources by isolated seedlings as the primary interaction for the understory of these mature forests.Key words: common mycorrhizal networks, facilitation, shade tolerance, competition.


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