scholarly journals Satellite monitoring of the state and dynamics of disturbed natural and technogenic landscapes in Siberia

Author(s):  
N.D. Yakimov ◽  
E.I. Ponomarev ◽  
T.V. Ponomareva

A method for monitoring recovery process in post-fire and post-technogenic landscapes was proposed based on satellite data in wide spectral range including the infrared bands data. The spectral albedo in short-wavelength bands (MODIS band #1 and #2) was underestimated by 20–48% relative to the background in the first year after the wildfire and remained underestimated by 3–12% after 20 years of vegetation restoration. For the variant of post-technogenic plot with reclamation, the albedo value was corresponded to the dynamics in post-fire plots, while for post-technogenic dumps without reclamation the level of the albedo underestimation remained 45–60% throughout the observation period (> 60 years). A decrease in the spectral albedo of the surface in post-fire areas, due to destruction of on-ground vegetation, provokes excessive heating of surface and upper soil layer. Surface thermal anomalies were evaluated under conditions of changes in the heat-insulating properties of vegetation and ground cover. Temperature anomalies in post-fire plots (overestimation up to 30%) are typical for permafrost conditions of Siberia. Similar process was recorded for both natural (post-fire) and post-technogenic landscapes. Within 20 years of the fire, thermal insulation properties of the vegetation cover restore. Thus, the relative temperature anomaly has reached the background value of 3 ± 1%. In post-technogenic plots conditions are more “contrast” compared to the background, and restoration of the thermal regime takes significantly longer period (> 60 years). Forming “neo-technogenic ecosystems” are characterized with specific thermal regimes of soils compared to the background ones both for reclaimed and for non-reclaimed post-technogenic plots. In averaged, surface temperature has overestimated at least by 10–15% in post-technogenic plots.

2021 ◽  
Vol 333 ◽  
pp. 02017
Author(s):  
Nikita Yakimov ◽  
Evgenii Ponomarev ◽  
Tatiana Ponomareva

A method for recovery monitoring in post-fire and post-technogenic landscapes was proposed based on satellite data in a wide spectral range, including the infrared band data. A decrease in the spectral surface albedo in post-fire areas, caused by the destruction of on-ground vegetation, provokes excessive heating of the surface and upper soil layer. Surface thermal anomalies were evaluated under conditions of changes in the heat-insulating properties of vegetation and ground cover. The relative temperature anomalies in post-fire plots (overestimation up to 30% compared to non-disturbed territory) are typical for permafrost conditions of Siberia. Similar process was recorded for both natural (post-fire) and post-technogenic landscapes. Within 22 years after the fire, thermal insulation properties of the vegetation cover were restored. Thus, the relative temperature anomaly (of 3±1%) has reached the background value. In post-technogenic plots, conditions are more “contrast” compared to the background, and restoration of the thermal regime takes significantly longer (>60 years). “Neo-technogenic ecosystems” with specific soil thermal regimes compared to the background ones are formed both for reclaimed and for non-reclaimed post-technogenic plots. On average, surface temperature has overestimated at least by 10–15% in post-technogenic plots compared to non-disturbed territory.


Weed Science ◽  
1985 ◽  
Vol 33 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Stephen C. Weller ◽  
Walter A. Skroch ◽  
Thomas J. Monaco

Field experiments conducted over a 2-yr period demonstrated that common bermudagrass [Cynodon dactylon (L.) Pers. # CYNDA] inhibited growth of newly planted peach (Prunus persica L. ‘Norman’) trees. Common bermudagrass densities of 100, 75, 50, and 25% ground cover reduced tree fresh weight by 86, 64, 43, and 19%, respectively, the first year (1978) and 87, 62, 44, and 28%, respectively, the second year (1979) after planting. Tree trunk diameter relative growth rate (RGR) was reduced by 75 and 100% common bermudagrass ground cover densities at all measurement dates only in 1978. Tree leaf N and K were reduced in both years by common bermudagrass; however, only at the 100% common bermudagrass density in 1978 was N at a deficient level. Leaf chlorophyll was reduced in trees grown in all densities of common bermudagrass only in 1978. Reduced tree growth cannot be explained entirely by competition for essential nutrients; thus an allelopathic effect of the bermudagrass on young peach roots is suspected.


1987 ◽  
Vol 14 (2) ◽  
pp. 163 ◽  
Author(s):  
D. Lunney ◽  
B. Cullis ◽  
P. Eby

This study of the effects of logging on small mammals in Mumbulla State Forest on the south coast of New South Wales included the effects of a fire in November 1980 and a drought throughout the study period from June 1980 to June 1983. Rattus fuscipes was sensitive to change: logging had a significant impact on its numbers, response to ground cover, and recapture rate; fire had a more severe effect, and drought retarded the post-fire recovery of the population. The three species of dasyurid marsupials differed markedly in their response to ground cover, canopy cover, logging and fire. Antechinus stuartii was distributed evenly through all habitats and was not affected by logging, but fire had an immediate and adverse effect which was sustained by the intense drought. A. swainsonii markedly preferred the regenerating forest, and was not seen again after the fire, the failure of the population being attributed to its dependence on dense ground cover. Sminthopsis leucopus was found in low numbers, appeared to prefer forest with sparse ground cover, and showed no immediate response to logging or fire; its disappearance by the third year post-fire suggests that regenerating forest is inimical to the survival of this species. Mus musculus showed no response to logging. In the first year following the fire its numbers were still very low, but in the next year there was a short-lived plague which coincided with the only respite in the 3-year drought and, importantly, occurred in the intensely burnt parts of the forest. The options for managing this forest for the conservation of small mammals include minimising fire, retaining unlogged forest, extending the time over which alternate coupes are logged and minimising disturbance from heavy machinery.


1963 ◽  
Vol 39 (3) ◽  
pp. 273-278 ◽  
Author(s):  
P. K. Heringa ◽  
R. G. H. Cormack

The present paper describes the ground vegetation of even-aged pine stands in West Central Alberta on six different sites and attempts to relate the ground vegetation to soil conditions.


Landslides ◽  
2020 ◽  
Vol 17 (11) ◽  
pp. 2631-2641
Author(s):  
Francis K. Rengers ◽  
Luke A. McGuire ◽  
Nina S. Oakley ◽  
Jason W. Kean ◽  
Dennis M. Staley ◽  
...  

Abstract In the semiarid Southwestern USA, wildfires are commonly followed by runoff-generated debris flows because wildfires remove vegetation and ground cover, which reduces soil infiltration capacity and increases soil erodibility. At a study site in Southern California, we initially observed runoff-generated debris flows in the first year following fire. However, at the same site three years after the fire, the mass-wasting response to a long-duration rainstorm with high rainfall intensity peaks was shallow landsliding rather than runoff-generated debris flows. Moreover, the same storm caused landslides on unburned hillslopes as well as on slopes burned 5 years prior to the storm and areas burned by successive wildfires, 10 years and 3 years before the rainstorm. The landslide density was the highest on the hillslopes that had burned 3 years beforehand, and the hillslopes burned 5 years prior to the storm had low landslide densities, similar to unburned areas. We also found that reburning (i.e., two wildfires within the past 10 years) had little influence on landslide density. Our results indicate that landscape susceptibility to shallow landslides might return to that of unburned conditions after as little as 5 years of vegetation recovery. Moreover, most of the landslide activity was on steep, equatorial-facing slopes that receive higher solar radiation and had slower rates of vegetation regrowth, which further implicates vegetation as a controlling factor on post-fire landslide susceptibility. Finally, the total volume of sediment mobilized by the year 3 landslides was much smaller than the year 1 runoff-generated debris flows, and the landslides were orders of magnitude less mobile than the runoff-generated debris flows.


1985 ◽  
Vol 36 (6) ◽  
pp. 791 ◽  
Author(s):  
AR Harradine

After 3 years of spread from sown infestations, slender thistle density in spring was 0.12 and 4.67 plants m-2 for plots in which the ground cover was dominated by cocksfoot and annual grass species, respectively. On plots maintained free of plants other than slender thistle ('bare plots'), the corresponding density was 47.31 plants m-2. Slender thistle seed was dispersed at least 10 m from the parent plant in the first year of seeding and plants were evenly spread over the bare plots after 2 years. After 3 years, slender thistle ingress was still occurring on the other plots. The results indicate the importance of ground cover, either of living plants or of litter, in reducing seedling establishment and seed dispersal of slender thistle.


1954 ◽  
Vol 32 (6) ◽  
pp. 760-783 ◽  
Author(s):  
Olli Vaartaja

Microclimate, especially temperature extremes, was studied on various plots of pine and spruce sites in Finland. Thermoelement measurements were made on clear, calm summer days. Comparisons showed that the climate of the exposed sites varied greatly from that of the sites with protective ground vegetation or canopy. Very large temperature differences between the sites existed at ground-level and moderately large differences at the 5 and 20 cm. levels. At exposed sites a temperature range of 57 °C. in 24 hr. was recorded in sandy surface soil, and still larger ranges seemed probable. Extreme diurnal fluctuation in temperature is evidently not closely correlated with general climate; it is favored by dryness of the soil and presence of ground cover, such as humus and fine litter, with low thermal conductivity. Maximum temperatures of 50° to 70 °C, are considered of normal occurrence in thin surface soil at exposed sites in large areas of northern coniferous forests. At the same time, maximum temperatures may remain from 9° to 13 °C. under the protection of canopy and surface cover, and night minima may be below 0 °C. in thin surface soil. A negative correlation was found between evaporation rate and drought injuries of plants on dry sites. Root competition was a more important factor to plants than evaporation conditions, at least as shown by the measurements from large vessels.


2014 ◽  
Vol 28 (3) ◽  
pp. 527-534 ◽  
Author(s):  
Nathan S. Boyd ◽  
Scott White ◽  
Kailang Rao

Winter bentgrass is a common, shallow-rooted perennial weed of lowbush blueberry fields. This unique production system is typically managed on a biannual cycle with blueberry shoot growth and floral bud development occurring in the first year (vegetative year) and berries harvested in the second year (crop year). An experiment was conducted in two commercial blueberry fields to determine the impact of 0, 143, or 286 kg ha−1of 14–18–10 fertilizer applied in the vegetative year, and fluazifop-P applications in the vegetative, crop, or both years of the biannual production cycle, on winter bentgrass and blueberry growth and yield. Fluazifop-P tended to reduce winter bentgrass biomass at both sites and the vegetative year-herbicide applications had a greater impact on winter bentgrass ground cover than crop-year applications. Total weed biomass following fluazifop-P applications was reduced in the vegetative year but not the crop year due to an increase in broadleaf weed biomass. Grass biomass tended to increase with fertility inputs in the vegetative year. In all years and sites, the application of fertilizers without herbicides increased grass biomass compared to the use of fertilizers combined with herbicides. Blueberry floral bud numbers per stem, flowers per stem, and berry yield tended to increase with vegetative year applications of fluazifop-P, although differences were not significant. These data indicate that winter bentgrass management is best achieved with herbicide applications in the vegetative year and this might result in yield increases, especially if broadleaf weeds also are adequately controlled.


2008 ◽  
Vol 17 (5) ◽  
pp. 559 ◽  
Author(s):  
Amy H. Groen ◽  
Scott W. Woods

Various methods are available to reduce post-wildfire erosion, but there is limited quantitative information on the relative effectiveness of these techniques. We used rainfall simulations to compare the erosion and runoff rates from adjacent 0.5-m2 plots treated with aerial grass seeding and straw mulch with untreated control plots following the July 2002 Fox Creek Fire in north-west Montana. In the first summer after the fire, plots seeded at a rate of 9 kg ha–1 had a mean of less than 5% ground cover and the seeding treatment had no effect on the rainsplash erosion rate. In contrast, straw mulch application at a rate of 2.24 Mg ha–1 resulted in ~100% ground cover and an 87% reduction in rainsplash erosion relative to the control (P = 0.001). Measurements on a subset of the plots in the second summer after the fire indicated that ground cover in the treatments and the control averaged 39%, and neither treatment provided a significant increase in ground cover or reduction in erosion relative to the control. These results add to the growing weight of evidence that straw mulch application is highly effective in reducing erosion in the first year after fire, whereas grass seeding is often ineffective because of the limited increase in ground cover that it produces.


1995 ◽  
Vol 25 (5) ◽  
pp. 713-723 ◽  
Author(s):  
Ingeborg Steijlen ◽  
Marie-Charlotte Nilsson ◽  
Olle Zackrisson

Six old-growth, late postfire Scots pine (Pinussylvestris L.) dominated forest stands of the Vaccinium–Cladina type were selected along a latitudinal gradient in northern Sweden. In two of the stands, Scots pine seedlings that had naturally regenerated during the last 40 years were surveyed in relation to field- and bottom-layer vegetation. The most abundant forest floor species, viz. Cladina spp., occupied 41% of the ground cover and dominated the microhabitat of Scots pine seedlings <10 years old. The second most common species, Pleuroziumschreberi (Bird.) Mitt., which occupied 10 and 20% of the ground cover at the two sites, was, in contrast, only found to cover less than 3% of the microhabitat of the seedlings < 10 years old. With increasing age of seedlings (>10 years), however, the cover of Cladina spp. significantly decreased and the cover of P. schreberi and various ericaceous species slightly increased. Thus Scots pine seedlings initially establish in lichen-dominated vegetation but as they develop P. schreberi and ericaceous species gradually become more abundant in the ground vegetation. The relationships between natural establishment patterns and microhabitat were further empirically tested by sowing seeds of Scots pine in patches of Cladina spp. and patches of P. schreberi. Seeding was performed in six sites during 3 consecutive years. A significant higher number of established Scots pine seedlings were found in Cladina spp. vegetation than in P. schreberi dominated vegetation, and Scots pine seedlings in P. schreberi experienced a significantly higher mortality. Laboratory studies indicated a negative chemical influence by P. schreberi on Scots pine seed germination but not on radicle growth of pregerminated seeds. The negative influence of P. schreberi on Scots pine seed germination and seedling survival in the field experiments is interpreted as an effect of moisture factors, chemical interference, and barriers of nutrient availability. Age structures of naturally established Scots pine showed evidence of continuous regeneration over the last 40 years. The study emphasizes the importance of biotically mediated regeneration patterns in explaining spatial stand structure and temporal dynamics in northern boreal Scots pine forest ecosystems during prolonged absence of fire. Tree regeneration tends not to be associated with mesoscale characteristics such as gaps and tip-up mounds, but rather with microhabitat conditions. The results have implications for predicting the effect of climatic warming.


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