TEMPERATURE AND EVAPORATION AT AND NEAR GROUND LEVEL ON CERTAIN FOREST SITES

1954 ◽  
Vol 32 (6) ◽  
pp. 760-783 ◽  
Author(s):  
Olli Vaartaja
Keyword(s):  
Surface Soil ◽  
Ground Cover ◽  
Ground Level ◽  
Root Competition ◽  
Diurnal Fluctuation ◽  
Large Temperature ◽  
Ground Vegetation ◽  
Forest Sites ◽  
Maximum Temperatures ◽  
General Climate

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.

Influence of temperature on maternity roost selection by noctule bats (Nyctalus noctula) and Leisler’s bats (N. leisleri) in Białowieża Primeval Forest, Poland

2006 ◽  
Vol 84 (6) ◽  
pp. 900-907 ◽  
Author(s):  
Ireneusz Ruczyński
Keyword(s):  
Late Pregnancy ◽  
Ground Level ◽  
Data Logger ◽  
Primeval Forest ◽  
Tree Cavities ◽  
Roost Selection ◽  
Pregnancy And Lactation ◽  
Maximum Temperatures ◽  
Białowieża Primeval Forest ◽  
Nyctalus Noctula

This study tests whether the temperature of tree cavities determines their selection by bats in Białowieża Primeval Forest (BPF), eastern Poland. Using a data logger, I simultaneously measured the temperature in cavities selected by bats as roosts and the temperature in available but unselected cavities. The maternity roosts chosen by noctule bats, Nyctalus noctula (Schreber, 1774), and Leisler’s bats, N. leisleri (Kuhl, 1817), during late pregnancy and lactation were warmer than unoccupied cavities, but temperature ranges in the two types of cavity did not differ. A logistic regression model showed that the mean cavity temperature during the night (2200–0400) and the minimum cavity temperature over a 24 h period were crucial for roost selection. This suggests that female noctule and Leisler’s bats selected roosts that promoted juvenile growth and used tree cavities that could save them energy while they were active because the cavity temperatures were close to the lower critical temperature of their thermoneutral zone. I also suggest that selection of warmer cavities minimized the bats' energy expenditure prior to emergence from the roost and that passive rewarming inside the cavity was an important factor in minimizing energetic costs of roosting by bats in BPF. Mean and maximum temperatures recorded near tree trunks increased with the height at which the temperature was measured (ground level, 10, 20, and 30 m), suggesting that bats can gain thermal benefits from insolation of the trunk by selecting highly placed cavities, as was observed in BPF.

scholarly journals RELATION OF SOILS AND GROUND COVER VEGETATION IN EVEN-AGED PINE STANDS OF CENTRAL ALBERTA

1963 ◽  
Vol 39 (3) ◽  
pp. 273-278 ◽  
Author(s):  
P. K. Heringa ◽  
R. G. H. Cormack
Keyword(s):  
Ground Cover ◽  
Soil Conditions ◽  
Ground Vegetation ◽  
West Central ◽  
Pine Stands ◽  
Ground Cover Vegetation

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.

Soil temperatures and seed burial in relation to the performance of Heteropogon contortus and Themeda australis in burnt native woodland pastures in Eastern Queensland

1969 ◽  
Vol 17 (2) ◽  
pp. 269 ◽  
Author(s):  
JC Tothill
Keyword(s):  
Ground Cover ◽  
Ground Level ◽  
Maximum Temperature ◽  
Seed Burial ◽  
Ambient Temperatures ◽  
Seasonally Dry ◽  
Heteropogon Contortus ◽  
Average Maximum ◽  
Soil Temperatures ◽  
Native Pastures

The factors underlying the increasing dominance of Heteropogon contortus (bunch or black spear grass) as a result of regularly burning native pastures in eastern Queensland have been investigated. In the subtropical environment of this experiment the removal of ground cover by burning or other means significantly increased the average maximum temperature of the surface soil. Burning favoured the germination of buried H. contortus seed at a time when ambient temperatures were too low for this to occur in unburnt situations. In late seasons and in the seasonally dry tropics insufficient soil moisture would tend to limit growth and germination until ambient temperatures are high, in which case the burning effect would be less pronounced. The efficient seed burial mechanism of H. contortus places it at an establishment advantage over other commonly associated species such as blue grasses (Bothriochloa, Dichanthium) and others whose seeds remain largely in the surface litter. Fire destroys much of this litter, the microhabitat for seed germination at ground level, and some of the weaker perennial plants. The implications of these results in relation to the increased dominance of either H. contortus or Themeda australis (kangaroo grass) are discussed.

Response of plant growth to removal of surface soil of the rangelands of western Queensland.

1987 ◽  
Vol 9 (2) ◽  
pp. 74 ◽  
Author(s):  
AJ Pressland ◽  
DC Cowan
Keyword(s):  
Surface Soil ◽  
Ground Cover ◽  
Field Studies ◽  
Potential Effect ◽  
Plant Production ◽  
Grass Species ◽  
Pasture Grass ◽  
Subsurface Soil ◽  
Test Plants ◽  
Or History

Pot and field studies were conducted to determine the potential effect on plant production of soil erosion in western Queensland. Soil from both the Mitchell grass (Astrebla spp.) and mulga (Acacin aneura) woodlands were used, but the studies concentrated on the latter soils. Test plants (oats, sorghum and pasture grass species) were grown in soil taken from sequential 5 cm intervals from the surface to 20 cm down the profile of each of the selected soils. Plants growing in subsurface soil, irrespective of soil type or history, were less productive than those growing on surface soil. This was attributed in part to reduced soil fertility and a difference in soil pH. Buffel grass (Cenchrur ciliaris), a species which has some use as an improved pasture in these rangelands, would be seriously disadvantaged on eroded soils. It is concluded that erosion of surface soil on these landscapes should be minimized by conserving ground cover.

scholarly journals Photosynthesis of boreal ground vegetation after a forest clear-cut

2009 ◽  
Vol 6 (11) ◽  
pp. 2495-2507 ◽  
Author(s):  
L. Kulmala ◽  
J. Pumpanen ◽  
T. Vesala ◽  
P. Hari
Keyword(s):  
Photosynthetic Activity ◽  
Calluna Vulgaris ◽  
Ground Level ◽  
Growing Season ◽  
Plant Size ◽  
Rubus Idaeus ◽  
Temperature History ◽  
Ground Vegetation ◽  
Clear Cut ◽  
Species Specific

Abstract. Heather (Calluna vulgaris), rosebay willowherb (Epilobium angustifolium), wavy hair-grass (Deschampsia flexuosa) and raspberry (Rubus idaeus) are typical species at boreal clear-cut sites. In this study, we measured their photosynthesis separately in the growing season of 2005 using a manual chamber. All measured species showed clear and species-specific seasonal cycles of photosynthetic activity (Pmax). The maxima of C. vulgaris and E. angustifolium occurred around June and July, while that of R. idaeus occurred as late as August. A simple model of photosynthetic activity is presented, addressing the photosynthesis of C. vulgaris was mainly explained by temperature history when the soil moisture is high. The activity of deciduous D. flexuosa also followed the temperature history, unlike the activities of E. angustifolium and R. idaeus. During a short drought, some shoots decreased their Pmax levels but none of the species showed similar reactions between individuals. We also observed that the comparison of the whole-plant Pmax or respiration of different-sized individuals were less scattered than the results based on full-grown leaf mass, implying that species-specific rates of photosynthesis at ground level are rather similar regardless of the plant size. Using species composition and continuous temperature and light measurements, we upscaled the species-specific process rates and integrated fixed and respired CO2 of ground vegetation for the entire 2005 growing season. The photosynthetic production per surface area of soil was 760 g C m−2 y−1 at the fertile site and 300 g C m−2 y−1 at the infertile site. During the snow-free period (18 April–21 November), the above ground parts of measured species released 75 g C m−2 y−1 at the infertile site. At the fertile site, E. angustifolium and R. idaeus respired 22 and 12 g C m−2 y−1, respectively.

scholarly journals Biological activity, nitrogen dynamics, and chemical characteristics of forest soils in the Šumava national park

2012 ◽  
Vol 49 (No. 7) ◽  
pp. 302-312 ◽  
Author(s):  
M. Svoboda
Keyword(s):  
Forest Soils ◽  
National Park ◽  
Large Scale ◽  
Ground Vegetation ◽  
Mountain Forest ◽  
Respiration Activity ◽  
Forest Sites ◽  
Tree Layer ◽  
Spruce Stands ◽  
Microclimatic Conditions

This paper deals with large-scale mountain forest decline in the Šumava National Park. The changes in biotic and abiotic properties of forest sites follow the tree layer disintegration. Changed microclimatic conditions such as intensity of irradiance, moisture and temperature of the top holorganic layers together with altered development of ground vegetation could strongly affect the values of microbiological respiration activity and the rates of nitrogen mineralization and nitrification. Soil substrates, built of organic mater, located on stony locations, are endangered by introskeletal erosion. This paper compares these features in pairs of research plots, consisting of dead or cut forest and of living stand. According to the results of this study, higher rates of organic matter decomposition, transformed dynamics of nitrogen and other nutrients and possible nutrient leaching from soil solutions were demonstrated in the forest floor under declined spruce stands. The extent and seriousness of these adverse processes for forest soils are strongly site dependent.

Seed regeneration of Scots pine in boreal forest stands dominated by lichen and feather moss

1995 ◽  
Vol 25 (5) ◽  
pp. 713-723 ◽  
Author(s):  
Ingeborg Steijlen ◽  
Marie-Charlotte Nilsson ◽  
Olle Zackrisson
Keyword(s):  
Seed Germination ◽  
Scots Pine ◽  
Field Experiments ◽  
Temporal Dynamics ◽  
Ground Cover ◽  
Tree Regeneration ◽  
Ground Vegetation ◽  
Forest Stands ◽  
Pine Seedlings ◽  
Natural Establishment

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.

scholarly journals Sampling event dataset for ecological monitoring of riparian restoration effort in Colorado foothills

2020 ◽  
Vol 8 ◽  
Author(s):  
Richard Levy ◽  
Margo Paces ◽  
Rebecca Hufft
Keyword(s):  
Species Abundance ◽  
Measurement Data ◽  
Ground Cover ◽  
Ground Vegetation ◽  
Botanic Gardens ◽  
Post Intervention ◽  
Aquatic Macroinvertebrate ◽  
Anthropogenic Habitat ◽  
Sampling Event ◽  
Restoration Effort

The foothills and shortgrass prairie ecosystems of Colorado, United States, have undergone substantial and sustained anthropogenic habitat change over the past two centuries. Riparian systems have been dramatically altered by agriculture, hydrological engineering, urbanisation and the introduction of non-native invasive species. In 2016, Denver Botanic Gardens began a restoration effort of Deer Creek which seeks to modify the hydrology of the creek by mimicking the effects of beaver dams with artificial structures. The site, owned by the US Army Core of Engineers and managed by Denver Botanic Gardens, had been the subject of previous botanical surveys. With the initiation of the restoration project, permanent transects were established along the stream and are sampled for ground vegetation richness and abundance, canopy cover, soil and stream conditions and aquatic macroinvertebrate community makeup on an annual basis. To provide a means for tracking any post-intervention changes in the riparian ecosystem, this resource reports all recorded occurrences and measurements, along with methodologies and motivations from past and current surveys in the form of a sampling event dataset. The current project and past surveys document 382 plant taxa and 157 aquatic macroinvertebrate taxa. A total of 16304 occurrences and 7422 measurements are included in the resource. Occurrence and measurement data taken from transects provide a means to measure species abundance, ground cover and other biotic and abiotic characteristics relevant to assessing the effects of hydrological restoration on riparian plant communities.

scholarly journals Satellite data in thermal range for natural and technogenic ecosystems monitoring

2021 ◽  
Vol 333 ◽  
pp. 02017
Author(s):  
Nikita Yakimov ◽  
Evgenii Ponomarev ◽  
Tatiana Ponomareva
Keyword(s):  
Satellite Data ◽  
Soil Layer ◽  
Ground Cover ◽  
Similar Process ◽  
Ground Vegetation ◽  
Infrared Band ◽  
Relative Temperature ◽  
Thermal Anomalies ◽  
Thermal Range ◽  
Technogenic Landscapes

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.

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