Soil nitrogen dynamics in high-altitude ski runs during the winter season (Monterosaski - Vallée d

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Freppaz, M.; Icardi, M.; Filippa, G.; Zanini, E.

2009-04-01

In many Alpine catchments, the development of winter tourism determined a widespread change in land use, shifting from forested and cultivated lands to ski slopes. The construction of a ski slope implies a strong impact on the landscape, with potential consequences on the soil quality. In most cases, the construction procedures include the total or partial removal of the soil body, the reallocation of the fine hearth fraction, the subsequent seeding of plants and the use of organic fertilizers. This work aims to evaluate soil physical and chemical properties and nitrogen (N) dynamics in anthropogenic soils from ski slopes of different age. Study sites were located in Champoluc (AO)- NW Italy between 2400 and 2700 m ASL. Topsoils (0-10 cm depth) were sampled in 4 ski slopes hydroseeded with commercial mixtures 4, 6, 10 and 12 years earlier, and in 4 control plots at the same exposure and altitude as the ski slopes. Soil samples were characterized, N dynamics in winter was evaluated with the buried bag technique and snowpack was analyzed for chemical and physical properties. Total nitrogen (TN) content in topsoil ranged 0.75-1.06 g kg-1 and was not correlated with the ski slope age. In all but one site, the TN content was significantly lower in the ski slope than in the control plot. A positive net ammonification and nitrification throughout the winter were found in all but one ski runs. These results suggest a high variability in the evolution degree of these anthropogenic soils. The net overwinter N mineralization that we report demonstrates that these soils are biologically active during the winter season. Such activity results in a pool of labile inorganic nitrogen potentially available for plant demand at the spring snowmelt.

Seasonal change in precipitation, snowpack, snowmelt, soil water and streamwater chemistry, northern Michigan

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Stottlemyer, R.; Toczydlowski, D.

1999-01-01

We have studied weekly precipitation, snowpack, snowmelt, soil water and streamwater chemistry throughout winter for over a decade in a small (176 ha) northern Michigan watershed with high snowfall and vegetated by 60 to 80 year-old northern hardwoods. In this paper, we examine physical, chemical, and biological processes responsible for observed seasonal change in streamwater chemistry based upon intensive study during winter 1996-1997. The objective was to define the contributions made to winter and spring streamwater chemical concentration and flux by processes as snowmelt, over-winter forest floor and surface soil mineralization, immobilization, and exchange, and subsurface flowpath. The forest floor and soil were unfrozen beneath the snowpack which permitted most snowmelt to enter. Over-winter soil mineralization and other biological processes maintain shallow subsurface ion and dissolved organic carbon (DOC) reservoirs. Small, but steady, snowmelt throughout winter removed readily mobilized soil NO3- which resulted in high over-winter streamwater concentrations but little flux. Winter soil water levels and flowpaths were generally deep which increased soil water and streamwater base cation (C(B)), HCO3-, and Si concentrations. Spring snowmelt increased soil water levels and removal of ions and DOC from the biologically active forest floor and shallow soils. The snowpack solute content was a minor component in determining streamwater ion concentration or flux during and following peak snowmelt. Exchangeable ions, weakly adsorbed anions, and DOC in the forest floor and surface soils dominated the chemical concentration and flux in soil water and streamwater. Following peak snowmelt, soil microbial immobilization and rapidly increased plant uptake of limiting nutrients removed nearly all available nitrogen from soil water and streamwater. During the growing season high evapotranspiration increased subsurface flowpath depth which in turn removed weathering

Soil CO2 efflux among four coniferous forest types of Kashmir Himalaya, India.

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Dar, Javid Ahmad; Ganie, Khursheed Ahmad; Sundarapandian, Somaiah

2015-11-01

Soil CO2 efflux was measured in four different coniferous forest types (Cedrus deodara (CD), Pinus wallichiana (PW), mixed coniferous (MC), and Abies pindrow (AP)) for a period of 2 years (April 2012 to December 2013). The monthly soil CO2 efflux ranged from 0.8 to 4.1 μmoles CO2 m(-2) s(-1) in 2012 and 1.01 to 5.48 μmoles CO2 m(-2) s(-1) in 2013. The soil CO2 efflux rate was highest in PW forest type in both the years, while it was lowest in MC and CD forest types during 2012 and 2013, respectively. Soil temperature (TS) at a depth of 10 cm ranged from 3.8 to 19.4 °C in 2012 and 3.5 to 19.1 °C in 2013 in all the four forest types. Soil moisture (MS) ranged from 19.8 to 58.6% in 2012 and 18.5 to 58.6% in 2013. Soil CO2 efflux rate was found to be significantly higher in summer than the other seasons and least during winter. Soil CO2 efflux showed a significant positive relationship with TS (R2=0.52 to 0.74), SOC% (R2=0.67), pH (R2=0.68), and shrub biomass (R2=0.51), whereas, only a weak positive relationship was found with soil moisture (R2=0.16 to 0.41), tree density (R2=0.25), tree basal area (R2=0.01), tree biomass (R2=0.07), herb biomass (R2=0.01), and forest floor litter (R2=0.02). Thus, the study indicates that soil CO2 efflux in high mountainous areas is greatly influenced by seasons, soil temperature, and other environmental factors.

Proceedings of the California Forest Soils Council Conference on Forest Soils Biology and Forest Management

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Robert F. Powers; Donald L. Hauxwell; Gary M. Nakamura

2000-01-01

Biotic properties of forest soil are the linkages connecting forest vegetation with an inert rooting medium to create a dynamic, functioning ecosystem. But despite the significance of these properties, managers have little awareness of the biotic world beneath their feet. Much of our working knowledge of soil biology seems anchored in myth and misunderstanding. To...

Soil Fauna Affects Dissolved Carbon and Nitrogen in Foliar Litter in Alpine Forest and Alpine Meadow.

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Liao, Shu; Yang, Wanqin; Tan, Yu; Peng, Yan; Li, Jun; Tan, Bo; Wu, Fuzhong

2015-01-01

Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) are generally considered important active biogeochemical pools of total carbon and nitrogen. Many studies have documented the contributions of soil fauna to litter decomposition, but the effects of the soil fauna on labile substances (i.e., DOC and TDN) in litter during early decomposition are not completely clear. Therefore, a field litterbag experiment was carried out from 13th November 2013 to 23rd October 2014 in an alpine forest and an alpine meadow located on the eastern Tibetan Plateau. Litterbags with different mesh sizes were used to provide access to or prohibit the access of the soil fauna, and the concentrations of DOC and TDN in the foliar litter were measured during the winter (the onset of freezing, deep freezing and thawing stage) and the growing season (early and late). After one year of field incubation, the concentration of DOC in the litter significantly decreased, whereas the TDN concentration in the litter increased. Similar dynamic patterns were detected under the effects of the soil fauna on both DOC and TDN in the litter between the alpine forest and the alpine meadow. The soil fauna showed greater positive effects on decreasing DOC concentration in the litter in the winter than in the growing season. In contrast, the dynamics of TND in the litter were related to seasonal changes in environmental factors, rather than the soil fauna. In addition, the soil fauna promoted a decrease in litter DOC/TDN ratio in both the alpine forest and the alpine meadow throughout the first year of decomposition, except for in the late growing season. These results suggest that the soil fauna can promote decreases in DOC and TDN concentrations in litter, contributing to early litter decomposition in these cold biomes.

Soil and soil cover changes in spruce forests after final logging

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E. M. Lapteva

2015-10-01

Full Text Available Soil cover transformation and changes of morphological and chemical properties of Albeluvisols in clear-cuttings of middle taiga spruce forests were studied. The observed changes in structure and properties of podzolic texturally-differentiated soils at cuttings of spruce forests in the middle taiga subzone do not cause their transition to any other soil type. Soil cover of secondary deciduous-coniferous forests which replace cut forests are characterized with a varied soil contour and a combination of the main type of podzolic soils under undisturbed spruce forests. The increased surface hydromorphism in cut areas causes formation of complicated sub-types of podzolic texturally differentiated soils (podzolic surface-gley soils with microprofile of podzol and enlarges their ratio (up to 35–38 % in soil cover structure. Temporary soil over-wetting at the initial (5–10 years stage of after-cutting self-restoring vegetation succession provides for soil gleyzation, improves yield and segregation of iron compounds, increases the migratory activity of humic substances. Low content and resources of total nitrogen in forest litters mark anthropogenic transformation processes of podzolic soils at this stage. Later (in 30–40 years after logging, soils in cut areas still retain signs of hydromorphism. Forest litters are denser, less acidic and thick with a low weight ratio of organic carbon as compared with Albeluvisols of undisturbed spruce forest. The upper mineral soil horizons under secondary deciduous-coniferous forests contain larger amounts of total iron, its mobile (oxalate-dissolvable components, and Fe-Mn-concretions.

Storm damage in the Black Forest caused by the winter storm "Lothar" – Part 1: Airborne damage assessment

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J. Schmoeckel

2008-08-01

Full Text Available An airborne survey of the Black Forest as affected by the winter storm "Lothar" in 1999 is performed by means of a color line scanner (CLS with a CCD sensor, whose data in a visible and a near-infrared channel provide the Normalized Difference Vegetation Index (NDVI as a measure of the damage in previously intact forest areas. The camera data, height data from a digital evelation model (DEM, land use information, and soil data are georeferenced and processed in a geographic information system (GIS to derive relationship of the damage pattern to the characteristics of the local orography and soil types. The data cover an area of 4900 km², 2767 km² of which were forested. The 363 detected storm damage areas with a minimum detection size of 1.5 ha amount to 0.8% of the total forest area. Visual inspections at certain sites prove that none of the larger damage areas are missed, but areas smaller than 1.5 ha cause the total damage area to be up to twice our result, i.e. ≈1.6% of the forest area. More than 50% of the detected damaged areas are smaller than 5 ha and most of them have a size ranging from 1.5 to 3.5 ha. Forests on slopes with an inclination angle between 10 and 15 degrees show the highest fraction of damaged forest, doubling those on plains and below 5 degrees inclination angle. Forests on northwestern slopes are more affected than those on southwestern and western slopes, which faced the wind during highest wind speed occurrence. In contrast to other studies, this paper shows, that in steep areas, lee slopes are more damaged than the luv slopes. As expected, wet to moist soils represent an unstable location for the trees. But also medium-dry to dry locations that were considered to be relatively stable exhibited a highly damaged forest fraction. This can be attributed to mostly saturated soil from previous rain.

Winter climate change and coastal wetland foundation species: salt marshes vs. mangrove forests in the southeastern United States.

Science.gov (United States)

Osland, Michael J; Enwright, Nicholas; Day, Richard H; Doyle, Thomas W

2013-05-01

We live in an era of unprecedented ecological change in which ecologists and natural resource managers are increasingly challenged to anticipate and prepare for the ecological effects of future global change. In this study, we investigated the potential effect of winter climate change upon salt marsh and mangrove forest foundation species in the southeastern United States. Our research addresses the following three questions: (1) What is the relationship between winter climate and the presence and abundance of mangrove forests relative to salt marshes; (2) How vulnerable are salt marshes to winter climate change-induced mangrove forest range expansion; and (3) What is the potential future distribution and relative abundance of mangrove forests under alternative winter climate change scenarios? We developed simple winter climate-based models to predict mangrove forest distribution and relative abundance using observed winter temperature data (1970-2000) and mangrove forest and salt marsh habitat data. Our results identify winter climate thresholds for salt marsh-mangrove forest interactions and highlight coastal areas in the southeastern United States (e.g., Texas, Louisiana, and parts of Florida) where relatively small changes in the intensity and frequency of extreme winter events could cause relatively dramatic landscape-scale ecosystem structural and functional change in the form of poleward mangrove forest migration and salt marsh displacement. The ecological implications of these marsh-to-mangrove forest conversions are poorly understood, but would likely include changes for associated fish and wildlife populations and for the supply of some ecosystem goods and services. © 2012 Blackwell Publishing Ltd.

Forest management strategy, spatial heterogeneity, and winter birds in Washington.

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B. Haveri; A.B. Carey

2000-01-01

Ecological management of second-growth forest holds great promise for conservation of biodiversity, yet little experimental evidence exists to compare alternative management approaches. Wintering birds are one of several groups of species most likely to be influenced by forest management activities. We compared species richness and proportion of stand area used over...

[Soil respiration characteristics in winter wheat field in North China Plain].

Science.gov (United States)

Chen, Shuyue; Li, Jun; Lu, Peiling; Wang, Yinghong; Yu, Qiang

2004-09-01

Experiments were conducted at the Yucheng Comprehensive Experimental Station of the Chinese Academy of Sciences during 2002-2003 to investigate the respiration of a pulverous sandstone soil under cultivation of winter wheat over a growth season. The effluent CO2 was collected and analyzed by the static-chamber/gas chromatography (GC) method at a frequency of once a week in spring and autumn, once two weeks in winter, twice a week for straw manure treatment, once a week for no straw manure treatment and nitrogen fertilization treatment in summer. The results indicated that diurnal variation of soil respiration rate showed a single peak in typical winter wheat farmlands in the North China Plain, and reached the highest at about 13 o'clock, and the lowest at about 4 o'clock in the early morning. In winter wheat growth season, the soil respiration rate was 31.23-606.85 mg x m(-2) x h(-1) under straw manure, 28.99-549.66 x m(-2) x h(-1) under no straw manure, 10.46-590.86 mg x m(-2) x h(-1) in N0, 16.11-349.88 mg x m(-2) x h(-1) in N100, 12.25-415.00 mg x m(-2) x h(-1) in N200, and 23.01-410.58 mg x m(-2) x h(-1) in N300, showing a similar seasonal variation tendency with soil temperature. Among all treatments, the straw manure had the most distinct soil respiration, though the soil respiration also increased slightly with increasing nitrogen fertilization. Soil respiration increased exponentially with increasing soil temperature, and the correlation of soil temperature at the depth of 5 cm was the best. This relationship was usually described with the Q10 model, which represented the sensitivity of soil respiration to temperature. Q10 was not a fixed value, which varied with the depth at which the temperature was measured and the depth of the active soil layer and soil temperature. At same time, the Q10 value decreased with increasing soil temperature. Soil water content was another important factor affecting soil respiration rate, but in this region, the relationship

Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field.

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Liang, Guopeng; Houssou, Albert A; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

2015-01-01

Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013-2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha(-1) year(-1) (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013-2014 and 2014-2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013-2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014-2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration.

Soil Fauna Communities and Soil Attributes in the Agroforests of Paraty

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Miguel Seabra Corrêa da Silva

Full Text Available ABSTRACT We conducted the present study in Paraty, southeastern Brazil, in areas under different management regimes and plant cover. The study comprised two different agroforestry systems (AFS-1 and AFS-2, a secondary forest, and a cassava monoculture. We aimed at assessing the effects of land use on the soil fauna and its relationship with soil chemical (pH, Al, Ca, Mg, P, K, carbon, and organic matter and microbiological attributes (soil microbial biomass carbon - SMB-C, soil respiration – SR, metabolic quotient - qCO2, microbial biomass carbon - C-mic. During winter, AFS-2 showed higher abundance of microphagous, saprophagous, and total individuals than the other areas. AFS-1 and the forest showed an increased abundance of Formicidae and phytophagous groups from winter to summer. The soil fauna and community structure showed that the studied agroforests are under regeneration, becoming more similar to the native forest, where ecological processes are considered efficient.

ALOS PALSAR Winter Coherence and Summer Intensities for Large Scale Forest Monitoring in Siberia

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Thiel, Christian; Thiel, Carolin; Santoro, Maurizio; Schmullius, Christiane

2008-11-01

In this paper summer intensity and winter coherence images are used for large scale forest monitoring. The intensities (FBD HH/HV) have been acquired during summer 2007 and feature the K&C intensity stripes [1]. The processing consisted of radiometric calibration, orthorectification, and topographic normalisation. The coherence has been estimated from interferometric pairs with 46-days repeat-pass intervals. The pairs have been acquired during the winters 2006/2007 and 2007/2008. During both winters suited weather conditions have been reported. Interferometric processing consisted of SLC co-registration at sub-pixel level, common-band filtering in range and azimuth and generation of a differential interferogram, which was used in the coherence estimation procedure based on adaptive estimation. All images were geocoded using SRTM data. The pixel size of the final SAR products is 50 m x 50 m. It could already be demonstrated, that by using PALSAR intensities and winter coherence forest and non-forest can be clearly separated [2]. By combining both data types hardly any overlap of the class signatures was detected, even though the analysis was conducted on pixel level and no speckle filter has been applied. Thus, the delineation of a forest cover mask could be executed operationally. The major hitch is the definition of a biomass threshold for regrowing forest to be distinguished as forest.

Effect of summer throughfall exclusion, summer drought, and winter snow cover on methane fluxes in a temperate forest soil

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Borken, W.; Davidson, E.A.; Savage, K.; Sundquist, E.T.; Steudler, P.

2006-01-01

Soil moisture strongly controls the uptake of atmospheric methane by limiting the diffusion of methane into the soil, resulting in a negative correlation between soil moisture and methane uptake rates under most non-drought conditions. However, little is known about the effect of water stress on methane uptake in temperate forests during severe droughts. We simulated extreme summer droughts by exclusion of 168 mm (2001) and 344 mm (2002) throughfall using three translucent roofs in a mixed deciduous forest at the Harvard Forest, Massachusetts, USA. The treatment significantly increased CH4 uptake during the first weeks of throughfall exclusion in 2001 and during most of the 2002 treatment period. Low summertime CH4 uptake rates were found only briefly in both control and exclusion plots during a natural late summer drought, when water contents below 0.15 g cm-3 may have caused water stress of methanotrophs in the A horizon. Because these soils are well drained, the exclusion treatment had little effect on A horizon water content between wetting events, and the effect of water stress was smaller and more brief than was the overall treatment effect on methane diffusion. Methane consumption rates were highest in the A horizon and showed a parabolic relationship between gravimetric water content and CH4 consumption, with maximum rate at 0.23 g H2O g-1 soil. On average, about 74% of atmospheric CH4 was consumed in the top 4-5 cm of the mineral soil. By contrast, little or no CH4 consumption occurred in the O horizon. Snow cover significantly reduced the uptake rate from December to March. Removal of snow enhanced CH4 uptake by about 700-1000%, resulting in uptake rates similar to those measured during the growing season. Soil temperatures had little effect on CH4 uptake as long as the mineral soil was not frozen, indicating strong substrate limitation of methanotrophs throughout the year. Our results suggest that the extension of snow periods may affect the annual rate

Soil fauna as an indicator of soil quality in forest stands, pasture and secondary forest

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Felipe Vieira da Cunha Neto

2012-11-01

Full Text Available The interactions between soil invertebrates and environmental variations are relatively unknown in the assessment of soil quality. The objective of this study was to evaluate soil quality in areas with different soil management systems, based on soil fauna as indicator, in Além Paraíba, Minas Gerais, Brazil. The soil invertebrate community was sampled using pitfall traps, in the dry and rainy seasons, from areas with five vegetation types (acacia, mimosa, eucalyptus, pasture, and secondary forest. The abundance of organisms and the total and average richness, Shannon's diversity index, the Pielou uniformity index, and change index V were determined. The fauna was most abundant in the areas of secondary forest and mimosa plantations in the dry season (111.3 and 31.7 individuals per trap per day, respectively. In the rainy season, the abundance of organisms in the three vegetation types did not differ. The highest values of average and total richness were recorded in the secondary forest in the dry season and in the mimosa stand in the rainy season. Shannon's index ranged from 1.57 in areas with acacia and eucalyptus in the rainy season to 3.19 in the eucalyptus area in the dry season. The uniformity index was highest in forest stands (eucalyptus, acacia and mimosa in the dry season, but higher in the rainy season in the pasture and secondary forest than in the forest stands. The change index V indicated that the percentage of extremely inhibited groups was lowest in the area with mimosa, both in the dry and rainy season (36 and 23 %, respectively. Of all forest stands, the mimosa area had the most abundant soil fauna.

Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field

Science.gov (United States)

Liang, Guopeng; Houssou, Albert A.; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

2015-01-01

Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013–2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha-1 year-1 (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013–2014 and 2014–2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013–2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014–2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration. PMID:26629695

Dependence of Soil Respiration on Soil Temperature and Soil Moisture in Successional Forests in Southern China

Institute of Scientific and Technical Information of China (English)

Xu-Li Tang; Guo-Yi Zhou; Shu-Guang Liu; De-Qiang Zhang; Shi-Zhong Liu; Jiong Li; Cun-Yu Zhou

2006-01-01

The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (± SD) soil respiration rate in the DNR forests was (9.0±4.6) Mg CO2-C/hm2 per year, ranging from (6.1±3.2) Mg CO2-C/hm2 per year in early successional forests to (10.7±4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

Dependence of soil respiration on soil temperature and soil moisture in successional forests in Southern China

Science.gov (United States)

Tang, X.-L.; Zhou, G.-Y.; Liu, S.-G.; Zhang, D.-Q.; Liu, S.-Z.; Li, Ji; Zhou, C.-Y.

2006-01-01

The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (±SD) soil respiration rate in the DNR forests was (9.0 ± 4.6) Mg CO2-C/hm2per year, ranging from (6.1 ± 3.2) Mg CO2-C/hm2per year in early successional forests to (10.7 ± 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities.

Soil strength and forest operations

OpenAIRE

Beekman, F.

1987-01-01

The use of heavy machinery and transport vehicles is an integral part of modern forest operations. This use often causes damage to the standing trees and to the soil. In this study the effects of vehicle traffic on the soil are analysed and the possible consequences for forest management discussed. The study is largely restricted to sandy and loamy soils because of their importance for Dutch forestry.

Soil strength, defined as the resistance of soil structure against the impa...

The Snow Must Go On: Ground Ice Encasement, Snow Compaction and Absence of Snow Differently Cause Soil Hypoxia, CO2 Accumulation and Tree Seedling Damage in Boreal Forest.

Science.gov (United States)

Martz, Françoise; Vuosku, Jaana; Ovaskainen, Anu; Stark, Sari; Rautio, Pasi

2016-01-01

At high latitudes, the climate has warmed at twice the rate of the global average with most changes observed in autumn, winter and spring. Increasing winter temperatures and wide temperature fluctuations are leading to more frequent rain-on-snow events and freeze-thaw cycles causing snow compaction and formation of ice layers in the snowpack, thus creating ice encasement (IE). By decreasing the snowpack insulation capacity and restricting soil-atmosphere gas exchange, modification of the snow properties may lead to colder soil but also to hypoxia and accumulation of trace gases in the subnivean environment. To test the effects of these overwintering conditions changes on plant winter survival and growth, we established a snow manipulation experiment in a coniferous forest in Northern Finland with Norway spruce and Scots pine seedlings. In addition to ambient conditions and prevention of IE, we applied three snow manipulation levels: IE created by artificial rain-on-snow events, snow compaction and complete snow removal. Snow removal led to deeper soil frost during winter, but no clear effect of IE or snow compaction done in early winter was observed on soil temperature. Hypoxia and accumulation of CO2 were highest in the IE plots but, more importantly, the duration of CO2 concentration above 5% was 17 days in IE plots compared to 0 days in ambient plots. IE was the most damaging winter condition for both species, decreasing the proportion of healthy seedlings by 47% for spruce and 76% for pine compared to ambient conditions. Seedlings in all three treatments tended to grow less than seedlings in ambient conditions but only IE had a significant effect on spruce growth. Our results demonstrate a negative impact of winter climate change on boreal forest regeneration and productivity. Changing snow conditions may thus partially mitigate the positive effect of increasing growing season temperatures on boreal forest productivity.

Carbon in boreal coniferous forest soil

Energy Technology Data Exchange (ETDEWEB)

Westman, C J; Ilvesniemi, H; Liski, J; Mecke, M [Helsinki Univ. (Finland). Dept. of Forest Ecology; Fritze, H; Helmisaari, H S; Pietikaeinen, J; Smolander, A [Finnish Forest Research Inst., Vantaa (Finland)

1997-12-31

The working hypothesis of the research was that the soil of boreal forests is a large carbon store and the amount of C is still increasing in young soils, like in the forest soils of Finland, which makes these soils important sinks for atmospheric CO{sub 2}. Since the processes defining the soil C balance, primary production of plants and decomposition, are dependent on environmental factors and site properties, it was assumed that the organic carbon pool in the soil is also dependent on the same factors. The soil C store is therefore likely to change in response to climatic warming. The aim of this research was to estimate the C balance of forest soil in Finland and predict changes in the balance in response to changes in climatic conditions. To achieve the aim (1) intensive empirical experimentation on the density of C in different pools in the soil and on fluxes between the pools was done was done, (2) the effect of site fertility and climate on the amount and properties of organic C in forest soil was investigated and (3) dynamic modelling for investigating dynamics of the soil C storage was used

Carbon in boreal coniferous forest soil

Energy Technology Data Exchange (ETDEWEB)

Westman, C.J.; Ilvesniemi, H.; Liski, J.; Mecke, M. [Helsinki Univ. (Finland). Dept. of Forest Ecology; Fritze, H.; Helmisaari, H.S.; Pietikaeinen, J.; Smolander, A. [Finnish Forest Research Inst., Vantaa (Finland)

1996-12-31

The working hypothesis of the research was that the soil of boreal forests is a large carbon store and the amount of C is still increasing in young soils, like in the forest soils of Finland, which makes these soils important sinks for atmospheric CO{sub 2}. Since the processes defining the soil C balance, primary production of plants and decomposition, are dependent on environmental factors and site properties, it was assumed that the organic carbon pool in the soil is also dependent on the same factors. The soil C store is therefore likely to change in response to climatic warming. The aim of this research was to estimate the C balance of forest soil in Finland and predict changes in the balance in response to changes in climatic conditions. To achieve the aim (1) intensive empirical experimentation on the density of C in different pools in the soil and on fluxes between the pools was done was done, (2) the effect of site fertility and climate on the amount and properties of organic C in forest soil was investigated and (3) dynamic modelling for investigating dynamics of the soil C storage was used

Estimation of soil respiration using automated chamber systems in an oak (Quercus mongolica) forest at the Nam-San site in Seoul, Korea.

Science.gov (United States)

Joo, Seung Jin; Park, Soon-Ung; Park, Moon-Soo; Lee, Chang Seok

2012-02-01

Soil respiration (R(soil)) is the largest component of ecosystem respiration produced by the autotrophic and heterotrophic respirations. Its variability on multiple time scales strongly depends on environmental variables such as temperature and moisture. To investigate the temporal variations of R(soil) in a cool-temperate oak (Quercus mongolica) forest at the Nam-San site in Seoul, Korea, continuous measurements of R(soil) using the automated chamber systems, air and soil temperatures and soil moisture are made for the period from April 2010 to March 2011. The observed data indicate that the R(soil) shows a remarkable seasonal variation in accordance with temperatures with high in summer and low in winter. The R(soil) is found to be strongly correlated with soil temperature (T(s)) at the 5cm depth throughout the year. However, the high fluctuation of R(soil) is found to be related with soil moisture content (M(s)) during the forest growing season. The estimated annual Q(10) value using the 1.5m-high air temperature is found to be 2.4 that is comparable with other studies in temperate forest ecosystems. The optimal regression equation of R(soil) with the T(s) at 5cm depth and the M(s) at 15cm depth is found to be R(soil)=124.3 exp (0.097T(s))-55.3 (M(s))(2)+2931.9 (M(s))-38516 for T(s)≥0°C and R(soil)=0 for T(s)soil). The annual total soil respiration estimated by the optimal regression equation is found to be 1264gCm(-2) with a maximum of 685gCm(-2) in the summer season and a minimum of 33gCm(-2) in the winter season. The present study can be implemented for the determination of the carbon balance of a cool-temperate Q. mongolica forest with the provision of photosynthesis. Copyright © 2011 Elsevier B.V. All rights reserved.

Summer fallow soil management - impact on rainfed winter wheat

DEFF Research Database (Denmark)

Li, Fucui; Wang, Zhaohui; Dai, Jian

2014-01-01

Summer fallow soil management is an important approach to improve soil and crop management in dryland areas. In the Loess Plateau regions, the annual precipitation is low and varies annually and seasonally, with more than 60% concentrated in the summer months from July to September, which...... is the summer fallow period in the winter wheat-summer fallow cropping system. With bare fallow in summer as a control, a 3-year location-fixed field experiment was conducted in the Loess Plateau to investigate the effects of wheat straw retention (SR), green manure (GM) planting, and their combination on soil...... water retention (WR) during summer fallow, winter wheat yield, and crop water use and nitrogen (N) uptake. The results showed that SR increased soil WR during summer fallow by 20 mm on average compared with the control over 3 experimental years but reduced the grain yield by 8% in the third year...

Winter climate limits subantarctic low forest growth and establishment.

Science.gov (United States)

Harsch, Melanie A; McGlone, Matt S; Wilmshurst, Janet M

2014-01-01

Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E) is oceanic (Conrad Index of Continentality  =  -5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

UNDERSTANDING AND APPLICABILITY OF THE FOREST SOIL CONCEPT

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Ana Paula Moreira Rovedder

2013-08-01

Full Text Available http://dx.doi.org/10.5902/1980509810563The forestry sector plays an important role in the socioeconomic and environmental Brazilian context, therefore the improvement of the knowledge about forest soil becomes essential for its sustainable use as a conservation base of natural heritage as resource for economical development. Forest soil can be characterized by pedogenesis occurred under influence of a forestry typology or under a currently natural or cultivated forest coverage. Differentiating forest soils from those occupied with other uses helps the understanding of possible alterations related to vegetal coverage and the developing of better management strategies to soil and forest use. Nevertheless, there is no consensus about this term because the soils present variations according to the forest characteristics, stimulating the discussion concerning its interpretation and applicability. This review aimed to analyze the utilization of forest soil concept, highlighting the differentiation characteristics and the relation with coverage type, natural or cultivated. Aspects related to deposition, quality and management of residues, nutrients cycling, soil compaction and site productivity are emphasized. The forest soil concept is widely used by specific literature and useful to collect specific information and to plan the sustainable use of soil and forest. The improvement of knowledge about these resources provides the creation of a common identity, supporting comparative studies and consolidating the research regarding to this theme.

Soil strength and forest operations

NARCIS (Netherlands)

Beekman, F.

1987-01-01

The use of heavy machinery and transport vehicles is an integral part of modern forest operations. This use often causes damage to the standing trees and to the soil. In this study the effects of vehicle traffic on the soil are analysed and the possible consequences for forest management

Nitrous oxide emission inventory of German forest soils

Science.gov (United States)

Schulte-Bisping, Hubert; Brumme, Rainer; Priesack, Eckart

2003-02-01

Annual fluxes of N2O trace gas emissions were assessed after stratifying German forest soils into Seasonal Emission Pattern (SEP) and Background Emission Pattern (BEP). Broad-leaved forests with soil pH(KCl) ≤ 3.3 were assigned to have SEP, broad-leaved forests with soil pH(KCl) > 3.3 and all needle-leaved forests to have BEP. BEPs were estimated by a relationship between annual N2O emissions and carbon content of the O-horizon. SEPs were primarily controlled by temperature and moisture and simulated by the model Expert-N after calibration to a 9-year record of N2O measurements. Analysis with different climate and soil properties indicated that the model reacts highly sensitive to changes in soil temperature, soil moisture, and soil texture. A geographic information system (ARC/INFO) was used for a spatial resolution of 1 km × 1 km grid where land cover, dominant soil units, and hygro climate classes were combined. The mean annual N2O emission flux from German forest soils was estimated as 0.32 kg ha-1 yr-1. Broad-leaved forests with SEP had the highest emissions (2.05 kg ha-1 yr-1) followed by mixed forests (0.38 kg ha-1 yr-1), broad-leaved forests (0.37 kg ha-1 yr-1), and needle-leaved forests with BEP (0.17 kg ha-1 yr-1). The annual N2O emission from German forest soils was calculated as 3.26 Gg N2O-N yr-1. Although needle-leaved trees cover about 57% of the entire forest area in Germany, their contribution is low (0.96 Gg N2O-N yr-1). Broad-leaved forests cover about 22% of the forest area but have 55% higher emissions (1.49 Gg N2O-N yr-1) than needle-leaved. Mixed forests cover 21% of the area and contribute 0.81 Gg N2O-N yr-1. Compared to the total N2O emissions in Germany of 170 Gg N yr-1, forest soils contribute only 1.9%. However, there are some uncertainties in this emission inventory, which are intensely discussed.

Acidification and Nitrogen Eutrophication of Austrian Forest Soils

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Robert Jandl

2012-01-01

Full Text Available We evaluated the effect of acidic deposition and nitrogen on Austrian forests soils. Until thirty years ago air pollution had led to soil acidification, and concerns on the future productivity of forests were raised. Elevated rates of nitrogen deposition were believed to cause nitrate leaching and imbalanced forest nutrition. We used data from a soil monitoring network to evaluate the trends and current status of the pH and the C : N ratio of Austrian forest soils. Deposition measurements and nitrogen contents of Norway spruce needles and mosses were used to assess the nitrogen supply. The pH values of soils have increased because of decreasing proton depositions caused by reduction of emissions. The C : N ratio of Austrian forest soils is widening. Despite high nitrogen deposition rates the increase in forest stand density and productivity has increased the nitrogen demand. The Austrian Bioindicator Grid shows that forest ecosystems are still deficient in nitrogen. Soils retain nitrogen efficiently, and nitrate leaching into the groundwater is presently not a large-scale problem. The decline of soil acidity and the deposition of nitrogen together with climate change effects will further increase the productivity of the forests until a limiting factor such as water scarcity becomes effective.

Soil moisture in sessile oak forest gaps

Science.gov (United States)

Zagyvainé Kiss, Katalin Anita; Vastag, Viktor; Gribovszki, Zoltán; Kalicz, Péter

2015-04-01

By social demands are being promoted the aspects of the natural forest management. In forestry the concept of continuous forest has been an accepted principle also in Hungary since the last decades. The first step from even-aged stand to continuous forest can be the forest regeneration based on gap cutting, so small openings are formed in a forest due to forestry interventions. This new stand structure modifies the hydrological conditions for the regrowth. Without canopy and due to the decreasing amounts of forest litter the interception is less significant so higher amount of precipitation reaching the soil. This research focuses on soil moisture patterns caused by gaps. The spatio-temporal variability of soil water content is measured in gaps and in surrounding sessile oak (Quercus petraea) forest stand. Soil moisture was determined with manual soil moisture meter which use Time-Domain Reflectometry (TDR) technology. The three different sizes gaps (G1: 10m, G2: 20m, G3: 30m) was opened next to Sopron on the Dalos Hill in Hungary. First, it was determined that there is difference in soil moisture between forest stand and gaps. Second, it was defined that how the gap size influences the soil moisture content. To explore the short term variability of soil moisture, two 24-hour (in growing season) and a 48-hour (in dormant season) field campaign were also performed in case of the medium-sized G2 gap along two/four transects. Subdaily changes of soil moisture were performed. The measured soil moisture pattern was compared with the radiation pattern. It was found that the non-illuminated areas were wetter and in the dormant season the subdaily changes cease. According to our measurements, in the gap there is more available water than under the forest stand due to the less evaporation and interception loss. Acknowledgements: The research was supported by TÁMOP-4.2.2.A-11/1/KONV-2012-0004 and AGRARKLIMA.2 VKSZ_12-1-2013-0034.

Winter climate limits subantarctic low forest growth and establishment.

Directory of Open Access Journals (Sweden)

Melanie A Harsch

Full Text Available Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E is oceanic (Conrad Index of Continentality  =  -5 with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C, dry winters (total winter precipitation <400 mm. Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

Winter Climate Limits Subantarctic Low Forest Growth and Establishment

Science.gov (United States)

Harsch, Melanie A.; McGlone, Matt S.; Wilmshurst, Janet M.

2014-01-01

Campbell Island, an isolated island 600 km south of New Zealand mainland (52°S, 169°E) is oceanic (Conrad Index of Continentality  = −5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6°C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026

The soil indicator of forest health in the Forest Inventory and Analysis Program

Science.gov (United States)

Michael C. Amacher; Charles H. Perry

2010-01-01

Montreal Process Criteria and Indicators (MPCI) were established to monitor forest conditions and trends to promote sustainable forest management. The Soil Indicator of forest health was developed and implemented within the USFS Forest Inventory and Analysis (FIA) program to assess condition and trends in forest soil quality in U.S. forests regardless of ownership. The...

Changes in soil respiration after thinning activities in dense Aleppo pine forests

Science.gov (United States)

Llovet, Joan; Alonso, Macià; Cerdà, Artemi

2015-04-01

variables (i.e. soil characteristics, potential soil heterotrophic respiration, plant biomass surrounding each plot, soil temperature, and soil moisture). Main results showed a seasonal variation of soil respiration as related by other authors (i.e. Almagro et al., 2009), being soil respiration restricted by drying during summer, and by low temperatures during winter. On the other hand, thinning significantly diminished soil respiration, its decrease was around 33% (from 5.3 micromole CO2 m-2 second-1, to 3.6 micromole CO2 m-2 second-1). Our results suggest that autotrophic respiration could be highly responsible of this decrease: we found significant and positive relationships between soil respiration and vegetation surrounding plots, and we did not find differences in potential soil heterotrophic respiration between treatments. Acknowledgements We thanks the financial support of the RESILIEN project funded by the Spanish Government, Ministerio de Ciencia e Innovación CGL2011-30515-C02-02. The RECARE project is funded by the European Commission FP7 program, ENV.2013.6.2-4 "Sustainable land care in Europe". References Almagro, M., López, J., Querejeta, J. I., Martínez Mena, M. 2009. Temperature dependence of soil CO2 efflux is strongly modulated by seasonal patterns of moisture availability in a Meditarranean ecosystem. Soil Biology and Biochemistry, 41. 594-605 Moreno, J.M., Vázquez, A., Vélez, R. 1998. Recent history of forest fires in Spain. In: Moreno, J. M. (ed). Large Fires. Backhuys Publishers, Leiden, The Netherlands, pp. 159-185. Pausas, J. G., Ribeiro, E., Vallejo, V. R. 2004. Post-fire regeneration variability of Pinus halepensis in the eastern Iberian Peninsula. Forest Ecology and Management, 203. 251-259. Ruiz Navarro, A., Barberá, G. G., Navarro Cano, J. A., Albaladejo, J., Castillo, V. M. 2009. Soil dynamics in Pinus halepensis reforestation: Effect of microenvironment and previous land use. Geoderma, 153. 353-361.

Food preferences of winter bird communities in different forest types.

Directory of Open Access Journals (Sweden)

Swen C Renner

Full Text Available Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity.

Revegetation of coal mine soil with forest litter

Energy Technology Data Exchange (ETDEWEB)

Day, A.D.; Ludeke, K.L.; Thames, J.L.

1986-11-01

Forest litter, a good source of organic matter and seeds, was applied on undisturbed soil and on coal mine (spoils) in experiments conducted on the Black Mesa Coal Mine near Kayenta, Arizona over a 2-year period (1977-1978). Germination, seedling establishment, plant height and ground cover were evaluated for two seeding treatments (forest litter and no forest litter) and two soil moisture treatments (natural rainfall and natural rainfall plus irrigation). The forest litter was obtained at random from the Coconino National Forest, broadcast over the surface of the soil materials and incorporated into the surface 5 cm of each soil material. Germination, seedling establishment, plant height and ground cover on undisturbed soil and coal mine soil were higher when forest litter was applied than when it was not applied and when natural rainfall was supplemented with sprinkler irrigation than when rainfall was not supplemented with irrigation. Applications of forest litter and supplemental irrigation may ensure successful establishment of vegetation on areas disturbed by open-pit coal mining.

Forest soil carbon is threatened by intensive biomass harvesting.

Science.gov (United States)

Achat, David L; Fortin, Mathieu; Landmann, Guy; Ringeval, Bruno; Augusto, Laurent

2015-11-04

Forests play a key role in the carbon cycle as they store huge quantities of organic carbon, most of which is stored in soils, with a smaller part being held in vegetation. While the carbon storage capacity of forests is influenced by forestry, the long-term impacts of forest managers' decisions on soil organic carbon (SOC) remain unclear. Using a meta-analysis approach, we showed that conventional biomass harvests preserved the SOC of forests, unlike intensive harvests where logging residues were harvested to produce fuelwood. Conventional harvests caused a decrease in carbon storage in the forest floor, but when the whole soil profile was taken into account, we found that this loss in the forest floor was compensated by an accumulation of SOC in deeper soil layers. Conversely, we found that intensive harvests led to SOC losses in all layers of forest soils. We assessed the potential impact of intensive harvests on the carbon budget, focusing on managed European forests. Estimated carbon losses from forest soils suggested that intensive biomass harvests could constitute an important source of carbon transfer from forests to the atmosphere (142-497 Tg-C), partly neutralizing the role of a carbon sink played by forest soils.

Winter survival of Scots pine seedlings under different snow conditions.

Science.gov (United States)

Domisch, Timo; Martz, Françoise; Repo, Tapani; Rautio, Pasi

2018-04-01

Future climate scenarios predict increased air temperatures and precipitation, particularly at high latitudes, and especially so during winter. Soil temperatures, however, are more difficult to predict, since they depend strongly on the fate of the insulating snow cover. 'Rain-on-snow' events and warm spells during winter can lead to thaw-freeze cycles, compacted snow and ice encasement, as well as local flooding. These adverse conditions could counteract the otherwise positive effects of climatic changes on forest seedling growth. In order to study the effects of different winter and snow conditions on young Scots pine (Pinus sylvestris L.) seedlings, we conducted a laboratory experiment in which 80 1-year-old Scots pine seedlings were distributed between four winter treatments in dasotrons: ambient snow cover (SNOW), compressed snow and ice encasement (ICE), flooded and frozen soil (FLOOD) and no snow (NO SNOW). During the winter treatment period and a 1.5-month simulated spring/early summer phase, we monitored the needle, stem and root biomass of the seedlings, and determined their starch and soluble sugar concentrations. In addition, we assessed the stress experienced by the seedlings by measuring chlorophyll fluorescence, electric impedance and photosynthesis of the previous-year needles. Compared with the SNOW treatment, carbohydrate concentrations were lower in the FLOOD and NO SNOW treatments where the seedlings had almost died before the end of the experiment, presumably due to frost desiccation of aboveground parts during the winter treatments. The seedlings of the ICE treatment showed dead needles and stems only above the snow and ice cover. The results emphasize the importance of an insulating and protecting snow cover for small forest tree seedlings, and that future winters with changed snow patterns might affect the survival of tree seedlings and thus forest productivity.

Diurnal Freeze-Thaw Cycles Modify Winter Soil Respiration in a Desert Shrub-Land Ecosystem

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Peng Liu

2016-07-01

Full Text Available Winter soil respiration (Rs is becoming a significant component of annual carbon budgets with more warming in winter than summer. However, little is known about the controlling mechanisms of winter Rs in dryland. We made continuous measurements of Rs in four microsites (non-crust (BS, lichen (LC, moss (MC, and a mixture of moss and lichen (ML in a desert shrub-land ecosystem northern China, to investigate the causes of Rs dynamics in winter. The mean winter Rs ranged from 0.10 to 0.17 µmol CO2 m−2·s−1 across microsites, with the highest value in BS. Winter Q10 (known as the increase in respiration rate per 10 °C increase in temperature values (2.8–19 were much higher than those from the growing season (1.5. Rs and Q10 were greatly enhanced in freeze-thaw cycles compared to frozen days. Diurnal patterns of Rs between freeze-thaw and frozen days differed. Although the freeze-thaw period was relatively short, its cumulative Rs contributed significantly to winter Rs. The presence of biocrust might induce lower temperature, thus having fewer freeze-thaw cycles relative to bare soil, leading to the lower Rs for microsites with biocrusts. In conclusion, winter Rs in drylands was sensitive to soil temperature (Ts and Ts-induced freeze-thaw cycles. The temperature impact on Rs varied among soil cover types. Winter Rs in drylands may become more important as the climate is continuously getting warmer.

Effects of vegetation type on microbial biomass carbon and nitrogen in subalpine mountain forest soils.

Science.gov (United States)

Ravindran, Anita; Yang, Shang-Shyng

2015-08-01

Microbial biomass plays an important role in nutrient transformation and conservation of forest and grassland ecosystems. The objective of this study was to determine the microbial biomass among three vegetation types in subalpine mountain forest soils of Taiwan. Tatachia is a typical high-altitude subalpine temperate forest ecosystem in Taiwan with an elevation of 1800-3952 m and consists of three vegetation types: spruce, hemlock, and grassland. Three plots were selected in each vegetation type. Soil samples were collected from the organic layer, topsoil, and subsoil. Microbial biomass carbon (Cmic) was determined by the chloroform fumigation-extraction method, and microbial biomass nitrogen (Nmic) was determined from the total nitrogen (Ntot) released during fumigation-extraction. Bacteria, actinomycetes, fungi, cellulolytic microbes, phosphate-solubilizing microbes, and nitrogen-fixing microbes were also counted. The Cmic and Nmic were highest in the surface soil and declined with the soil depth. These were also highest in spruce soils, followed by in hemlock soils, and were lowest in grassland soils. Cmic and Nmic had the highest values in the spring season and the lowest values in the winter season. Cmic and Nmic had significantly positive correlations with total organic carbon (Corg) and Ntot. Contributions of Cmic and Nmic, respectively, to Corg and Ntot indicated that the microbial biomass was immobilized more in spruce and hemlock soils than in grassland soils. Microbial populations of the tested vegetation types decreased with increasing soil depth. Cmic and Nmic were high in the organic layer and decreased with the depth of layers. These values were higher for spruce and hemlock soils than for grassland soils. Positive correlations were observed between Cmic and Nmic and between Corg and Ntot. Copyright © 2014. Published by Elsevier B.V.

Unravelling the importance of forest age stand and forest structure driving microbiological soil properties, enzymatic activities and soil nutrients content in Mediterranean Spanish black pine(Pinus nigra Ar. ssp. salzmannii) Forest.

Science.gov (United States)

Lucas-Borja, M E; Hedo, J; Cerdá, A; Candel-Pérez, D; Viñegla, B

2016-08-15

This study aimed to investigate the effects that stand age and forest structure have on microbiological soil properties, enzymatic activities and nutrient content. Thirty forest compartments were randomly selected at the Palancares y Agregados managed forest area (Spain), supporting forest stands of five ages; from 100 to 80years old to compartments with trees that were 19-1years old. Forest area ranging from 80 to 120years old and without forest intervention was selected as the control. We measured different soil enzymatic activities, soil respiration and nutrient content (P, K, Na, Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb and Ca) in the top cm of 10 mineral soils in each compartment. Results showed that the lowest forest stand age and the forest structure created by management presented lower values of organic matter, soil moisture, water holding capacity and litterfall and higher values of C/N ratio in comparison with the highest forest stand age and the related forest structure, which generated differences in soil respiration and soil enzyme activities. The forest structure created by no forest management (control plot) presented the highest enzymatic activities, soil respiration, NH4(+) and NO3(-). Results did not show a clear trend in nutrient content comparing all the experimental areas. Finally, the multivariate PCA analysis clearly clustered three differentiated groups: Control plot; from 100 to 40years old and from 39 to 1year old. Our results suggest that the control plot has better soil quality and that extreme forest stand ages (100-80 and 19-1years old) and the associated forest structure generates differences in soil parameters but not in soil nutrient content. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of fire disturbance on soil respiration in the non-growing season in a Larix gmelinii forest in the Daxing'an Mountains, China.

Science.gov (United States)

Hu, Tongxin; Sun, Long; Hu, Haiqing; Guo, Futao

2017-01-01

In boreal forests, fire is an important part of the ecosystem that greatly influences soil respiration, which in turn affects the carbon balance. Wildfire can have a significant effect on soil respiration and it depends on the fire severity and environmental factors (soil temperature and snow water equivalent) after fire disturbance. In this study, we quantified post-fire soil respiration during the non-growing season (from November to April) in a Larix gmelinii forest in Daxing'an Mountains of China. Soil respiration was measured in the snow-covered and snow-free conditions with varying degrees of natural burn severity forests. We found that soil respiration decreases as burn severity increases. The estimated annual C efflux also decreased with increased burn severity. Soil respiration during the non-growing season approximately accounted for 4%-5% of the annual C efflux in all site types. Soil temperature (at 5 cm depth) was the predominant determinant of non-growing season soil respiration change in this area. Soil temperature and snow water equivalent could explain 73%-79% of the soil respiration variability in winter snow-covering period (November to March). Mean spring freeze-thaw cycle (FTC) period (April) soil respiration contributed 63% of the non-growing season C efflux. Our finding is key for understanding and predicting the potential change in the response of boreal forest ecosystems to fire disturbance under future climate change.

Mechanisms controlling radionuclide mobility in forest soils

International Nuclear Information System (INIS)

Delvaux, B.; Kruyts, N.; Maes, E.; Agapkina, G.I.; Kliashtorin, A.; Bunzl, K.; Rafferty, B.

1996-01-01

Soil processes strongly influence the radionuclide mobility in soils. The mobility of radionuclides in forest soils is governed by several processes involving both abiotic and biotic factors. The sorption-desorption process chiefly governs the activity of radionuclides in the soil solution, hence thereby their mobility and biological availability. Radiocaesium exhibits a very low mobility in mineral soils. Both mobility and bioavailability however increase as the thickness of organic layers and their content in organic matter increases. Clay minerals of micaceous origin strongly act as slinks for radiocaesium in forest soils. The magnitude of cesium mineral fixation in topsoils is expected to be the highest in mineral soils of Eutric cambisol type, and, to a lesser extent, of type of Distric cambisol and Podzoluvisol. A low mobility of radiocaesium in the surface horizons of forest soils may also be partially explained by a biological mobilization: fungi absorb radiocaesium and transport it to upper layers, thereby contributing to constantly recycle the radioelement in the organic horizons. This mechanism is probably important in soils with thick organic layers (Podsol, Histosol, and, to a lesser extent, Distric cambisol and Podzoluvisol). Radionuclides can be associated with soluble organic anions in the soil solution of forest acid soils. Such associations are highly mobile: they are stable in conditions of poor biological activity (low temperatures, acid soil infertility, water excess, etc.). Their magnitude is expected to be the highest in thick acid organic layers (soils of type Podzol and Histosol)

Winter time burst of CO2 from the High Arctic soils of Svalbard

DEFF Research Database (Denmark)

Friborg, Thomas; Hansen, Birger; Elberling, Bo

of relatively few measurements which appear to give small and constant emission rates. Further, most studies of the processes behind winter time emission of CO2 conclude that the flux during this time of year can be linked to the respiratory release of CO2 from soil micro organisms, which is temperature...... the winter at a high arctic location in Svalbard (78°N). Measurements were conducted in the field during the winter season of 2004-2005 and show reliable and continuous measurements of CO2 fluxes down to a level of 0.01 ìmol m-2 s-1 and good correspondence with other types of soil chambers. Our results...... indicate that a substantial part of the annual CO2 emission from the ecosystem occur during the freeze in period, where more CO2 is emitted from the soil over a few weeks than the accumulated flux for the rest of the winter. During the coldest part of the...

Controls on winter ecosystem respiration in temperate and boreal ecosystems

Directory of Open Access Journals (Sweden)

T. Wang

2011-07-01

Full Text Available Winter CO₂ fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (R_eco of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter R_eco rates (0.90 ± 0.39 g C m⁻² d⁻¹, when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter R_eco rates (0.02 ± 0.02 g C m⁻² d⁻¹. Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter R_eco rates (g C m⁻² d⁻¹ of 0.70(±0.33, 0.60(±0.38, 0.62(±0.43, 0.49(±0.22 and 0.27(±0.08, respectively. Our cross site analysis showed that winter air (T_air and soil (T_soil temperature played a dominating role in determining the spatial patterns of winter R_eco in both forest and managed ecosystems (grasslands and croplands. Besides temperature, the seasonal amplitude of the leaf area index (LAI, inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for R_eco in the subsequent winter, played a marginal role in winter CO₂ emissions from forest ecosystems. We found that winter R_eco sensitivity to temperature variation across space (

Soil mineralogy and microbes determine forest life history strategy and carbon cycling in humid tropical forests

Science.gov (United States)

Soong, J.; Verbruggen, E.; Peñuelas, J.; Janssens, I. A.; Grau, O.

2017-12-01

Tropical forests account for over one third of global terrestrial gross primary productivity and cycle more C than any other ecosystem on Earth. However, we still lack a mechanistic understanding of how such high productivity is maintained on the old, highly weathered and phosphorus depleted soils in the tropics. We hypothesized that heterogeneity in soil texture, mineralogy and microbial community composition may be the major drivers of differences in soil C storage and P limitation across tropical forests. We sampled 12 forest sites across a 200 km transect in the humid neo-tropics of French Guiana that varied in soil texture, precipitation and mineralogy. We found that soil texture was a major driver of soil carbon stocks and forest life history strategy, where sandy forests have lower soil C stocks, slower turnover and decomposition and a more closed nutrient cycle while clayey forests have higher soil C stocks, faster turnover and a more leaky nutrient cycle (using natural abundance stable isotope evidence). We found that although the presence of Al and Fe oxides in the clayey soils occludes soil organic matter and P, a greater abundance of arbuscular mycorrhizal fungi help forests to access occluded P in clayey soils fueling higher turnover and faster decomposition rates. Evidence from a laboratory incubation of tropical soils with nutrient additions further demonstrates the de-coupling of microbial P demands from C:N limitations providing further evidence for the need to examine microbial stoichiometry to explain C cycling in the P-limited tropics. We argue that microbial community composition and physiological demands, constrained within the limitations of soil mineralogical reactivity, largely controls nutrient and C cycling in tropical forest soils. Together our observational field study and laboratory incubation provide a unique dataset to shed light on the mineralogical and microbial controls on C and nutrient cycling in tropical soils. By integrating

Ecological factors governing the distribution of soil microfungi in some forest soils of Pachmarhi Hills, India

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Shashi Chauhan

2014-01-01

Full Text Available An ecological study of the microfungi occurring in the various forest soils of Pachmarhi Hills, India has been carried-out by the soil plate technique. Soil samples from 5 different forest communities viz., moist deciduous forest dominated by tree ferns, Diospyros forest, Terminalia forest, Shorea forest and scrub forest dominated by Acacia and Dalbergia sp. were collected during October, 1983. Some physico-chemical characteristics of the soil were analysed and their role in distribution of fungi in 5 soil types was studied and discussed. 43 fungal species were isolated, of which Asperigillus niger I and Penicillium janthinellum occurred in all the 5 soil types. Statistically, none of the edaphic factors showed positive significant correlation with the number of fungi.

Modelling soil water content variations under drought stress on soil column cropped with winter wheat

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Csorba Szilveszter

2014-12-01

Full Text Available Mathematical models are effective tools for evaluating the impact of predicted climate change on agricultural production, but it is difficult to test their applicability to future weather conditions. We applied the SWAP model to assess its applicability to climate conditions, differing from those, for which the model was developed. We used a database obtained from a winter wheat drought stress experiment. Winter wheat was grown in six soil columns, three having optimal water supply (NS, while three were kept under drought-stressed conditions (S. The SWAP model was successfully calibrated against measured values of potential evapotranspiration (PET, potential evaporation (PE and total amount of water (TSW in the soil columns. The Nash-Sutcliffe model efficiency coefficient (N-S for TWS for the stressed columns was 0.92. For the NS treatment, we applied temporally variable soil hydraulic properties because of soil consolidation caused by regular irrigation. This approach improved the N-S values for the wetting-drying cycle from -1.77 to 0.54. We concluded that the model could be used for assessing the effects of climate change on soil water regime. Our results indicate that soil water balance studies should put more focus on the time variability of structuredependent soil properties.

Soil carbon storage estimation in a forested watershed using quantitative soil-landscape modeling

Science.gov (United States)

James A. Thompson; Randall K. Kolka

2005-01-01

Carbon storage in soils is important to forest ecosystems. Moreover, forest soils may serve as important C sinks for ameliorating excess atmospheric CO2. Spatial estimates of soil organic C (SOC) storage have traditionally relied upon soil survey maps and laboratory characterization data. This approach does not account for inherent variability...

Dynamic of radionuclides behaviour in forest soils

International Nuclear Information System (INIS)

Ruehm, W.; Steiner, M.; Wirth, E.; Dvornik, A.; Zhuchenko, T.A.; Kliashtorin, A.; Rafferty, B.; Shaw, G.; Kuchma, N.

1996-01-01

Within the research project ECP-5, the dynamics of radionuclides in automorphic forest soils within the 30-km-zone of Chernobyl and of hydromorphic forest soils in Belarus have been investigated. In upland forest soils, the lower layers of the organic horizons are characterized by the highest residence times for radiocesium and represent the largest pool for all radionuclides investigated. According to a preliminary estimate, radiocesium is more mobile compared to 125 Sb, which in turn migrates faster than 60 Co, 144 Ce, and 154 Eu. 106 Ru shows the lowest mobility. With regard to radiocesium, hydromorphic soils exhibit migration rates and transfer factors from soil to trees, which by far exceed those in automorphic soils. Based on a two-component quasi-diffusional model the average bias of 137 Cs in mesotrophic swamp soils was predicted. The activity concentrations of U, Pu, and Cs suggest that U and Pu were originally deposited as hot particles and that U is naturally accumulated in organic horizons

Soil Effects on Forest Structure and Diversity in a Moist and a Dry Tropical Forest

NARCIS (Netherlands)

Peña-Claros, M.; Poorter, L.; Alarcon, A.; Blate, G.; Choque, U.; Fredericksen, T.S.; Justiniano, J.; Leaño, C.; Licona, J.C.; Pariona, W.; Putz, F.E.; Quevedo, L.; Toledo, M.

2012-01-01

Soil characteristics are important drivers of variation in wet tropical forest structure and diversity, but few studies have evaluated these relationships in drier forest types. Using tree and soil data from 48 and 32 1 ha plots, respectively, in a Bolivian moist and dry forest, we asked how soil

Effects of fire disturbance on soil respiration in the non-growing season in a Larix gmelinii forest in the Daxing'an Mountains, China.

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Tongxin Hu

Full Text Available In boreal forests, fire is an important part of the ecosystem that greatly influences soil respiration, which in turn affects the carbon balance. Wildfire can have a significant effect on soil respiration and it depends on the fire severity and environmental factors (soil temperature and snow water equivalent after fire disturbance. In this study, we quantified post-fire soil respiration during the non-growing season (from November to April in a Larix gmelinii forest in Daxing'an Mountains of China. Soil respiration was measured in the snow-covered and snow-free conditions with varying degrees of natural burn severity forests. We found that soil respiration decreases as burn severity increases. The estimated annual C efflux also decreased with increased burn severity. Soil respiration during the non-growing season approximately accounted for 4%-5% of the annual C efflux in all site types. Soil temperature (at 5 cm depth was the predominant determinant of non-growing season soil respiration change in this area. Soil temperature and snow water equivalent could explain 73%-79% of the soil respiration variability in winter snow-covering period (November to March. Mean spring freeze-thaw cycle (FTC period (April soil respiration contributed 63% of the non-growing season C efflux. Our finding is key for understanding and predicting the potential change in the response of boreal forest ecosystems to fire disturbance under future climate change.

Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

Science.gov (United States)

M. Mazur; C.P.J. Mitchell; C.S. Eckley; S.L. Eggert; R.K. Kolka; S.D. Sebestyen; E.B. Swain

2014-01-01

Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil-air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown.We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg...

Benchmark values for forest soil carbon stocks in Europe

DEFF Research Database (Denmark)

De Vos, Bruno; Cools, Nathalie; Ilvesniemi, Hannu

2015-01-01

Soil organic carbon (SOC) stocks in forest floors and in mineral and peat forest soils were estimated at the European scale. The assessment was based on measured C concentration, bulk density, coarse fragments and effective soil depth data originating from 4914 plots in 22 EU countries belonging...... to the UN/ECE ICP Forests 16 × 16 km Level I network. Plots were sampled and analysed according to harmonized methods during the 2nd European Forest Soil Condition Survey. Using continuous carbon density depth functions, we estimated SOC stocks to 30-cm and 1-m depth, and stratified these stocks according...... to 22 WRB Reference Soil Groups (RSGs) and 8 humus forms to provide European scale benchmark values. Average SOC stocks amounted to 22.1 t C ha− 1 in forest floors, 108 t C ha− 1 in mineral soils and 578 t C ha− 1 in peat soils, to 1 m depth. Relative to 1-m stocks, the vertical SOC distribution...

Smog nitrogen and the rapid acidification of forest soil, San Bernardino Mountains, southern California.

Science.gov (United States)

Wood, Yvonne A; Fenn, Mark; Meixner, Thomas; Shouse, Peter J; Breiner, Joan; Allen, Edith; Wu, Laosheng

2007-03-21

We report the rapid acidification of forest soils in the San Bernardino Mountains of southern California. After 30 years, soil to a depth of 25 cm has decreased from a pH (measured in 0.01 M CaCl2) of 4.8 to 3.1. At the 50-cm depth, it has changed from a pH of 4.8 to 4.2. We attribute this rapid change in soil reactivity to very high rates of anthropogenic atmospheric nitrogen (N) added to the soil surface (72 kg ha(-1) year(-1)) from wet, dry, and fog deposition under a Mediterranean climate. Our research suggests that a soil textural discontinuity, related to a buried ancient landsurface, contributes to this rapid acidification by controlling the spatial and temporal movement of precipitation into the landsurface. As a result, the depth to which dissolved anthropogenic N as nitrate (NO3) is leached early in the winter wet season is limited to within the top approximately 130 cm of soil where it accumulates and increases soil acidity.

Smog Nitrogen and the Rapid Acidification of Forest Soil, San Bernardino Mountains, Southern California

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Yvonne A. Wood

2007-01-01

Full Text Available We report the rapid acidification of forest soils in the San Bernardino Mountains of southern California. After 30 years, soil to a depth of 25 cm has decreased from a pH (measured in 0.01 M CaCl2 of 4.8 to 3.1. At the 50-cm depth, it has changed from a pH of 4.8 to 4.2. We attribute this rapid change in soil reactivity to very high rates of anthropogenic atmospheric nitrogen (N added to the soil surface (72 kg ha–1 year–1 from wet, dry, and fog deposition under a Mediterranean climate. Our research suggests that a soil textural discontinuity, related to a buried ancient landsurface, contributes to this rapid acidification by controlling the spatial and temporal movement of precipitation into the landsurface. As a result, the depth to which dissolved anthropogenic N as nitrate (NO3 is leached early in the winter wet season is limited to within the top ~130 cm of soil where it accumulates and increases soil acidity.

Soils characterisation along ecological forest zones in the Eastern Himalayas

Science.gov (United States)

Simon, Alois; Dhendup, Kuenzang; Bahadur Rai, Prem; Gratzer, Georg

2017-04-01

Elevational gradients are commonly used to characterise vegetation patterns and, to a lesser extent, also to describe soil development. Furthermore, interactions between vegetation cover and soil characteristics are repeatedly observed. Combining information on soil development and easily to distinguish forest zones along elevational gradients, creates an added value for forest management decisions especially in less studied mountain regions. For this purpose, soil profiles along elevational gradients in the temperate conifer forests of Western and Central Bhutan, ranging from 2600-4000m asl were investigated. Thereby, 82 soil profiles were recorded and classified according to the World Reference Base for Soil Resources. Based on 19 representative profiles, genetic horizons were sampled and analysed. We aim to provide fundamental information on forest soil characteristics along these elevational transects. The results are presented with regard to ecological forest zones. The elevational distribution of the reference soil groups showed distinct distribution ranges for most of the soils. Cambisols were the most frequently recorded reference soil group with 58% of the sampled profiles, followed by Podzols in higher elevations, and Stagnosols, at intermediate elevations. Fluvisols occurred only at the lower end of the elevational transects and Phaeozems only at drier site conditions in the cool conifer dry forest zone. The humus layer thickness differs between forest zones and show a shift towards increased organic layer (O-layer) with increasing elevation. The reduced biomass productivity with increasing elevation and subsequently lower litter input compensates for the slow decomposition rates. The increasing O-layer thickness is an indicator of restrained intermixing of organic and mineral components by soil organisms at higher elevation. Overall, the soil types and soil characteristics along the elevational gradient showed a continuous and consistent change, instead

Soil physical attributes in forms of sowing the annual winter pasture and intervals between grazing

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Milton da Veiga

Full Text Available The sowing of winter pastures in areas used for summer grain production and their management under direct cattle grazing can cause changes in soil physical attributes, whose intensity depends on the degree of soil mobilization, grazing interval, stocking rate and weather. To study these aspects it was conducted over four years an experiment in a randomized block with split plots design and four replications. In the main plots were applied two forms of sowing the annual winter pasture (direct seeding and seeding + harrowing and, in the subplots, four intervals between grazing (7, 14 and 28 days and ungrazed. Undisturbed soil cores were sampled at the end of each grazing cycle, in the 0-0.05 m layer to determine the saturated hydraulic conductivity and aggregate stability and in the layers of 0-0.05, 0.05-0.10, 0.10-0.15 and 0.15-0.20 m depth to determine bulk density and classes of soil pores. The direct seeding of annual winter pasture increases hydraulic conductivity and reduces soil bulk density in relation to seeding + harrowing while dairy cows trampling increases soil density and reduces macroporosity in the most superficial soil layer. The variation in climatic conditions among grazing cycles affects the soil physical attributes more markedly than forms of sowing and intervals between grazing of the annual winter pasture.

SOIL QUALITY CHANGES FOLLOWING FOREST CLEARANCE IN BENGKULU, SUMATRA

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I.P. HANDAYANI

2004-01-01

Full Text Available Intense destruction and degradation of tropical forests is recognized as one of the environmental threats and tragedies. These have increased the need to assess the effects of subsequent land-use following forest extraction on soil quality. Therefore, the objective of this study is to evaluate the impacts of land-use type on soil quality properties in Bengkulu Province, Sumatra. Soil samples were collected from adjacent sites including natural secondary forest, bare land, cultivated land and grassland. The results show that land-use following forest clearance lowered saturated hydraulic conductivity (85%, porosity (10.50%, soil water content at field capacity (34%,C organic (27%, N total (26%, inorganic N (37%, soil microbial biomass C (32%, mineralizable C (22%, and particulate organic matter (50%, but slightly increased water soluble organic C. Specific respiration activi ty rates increased about 14% in cultivated soils compared to natural forest soils, indicating greater C turnover per labile C pool in the form of soil microbial biomass, thus decreased biologically active soil organic matter. Forest conversion tends to reduce the C,ffg/Crer for all deforested sites. All of deforested areas relatively have infertile soil, with the worst case found in cultivated field. The C^g/Crd of cultivated field s was about 24% less than that of remnant fo rest (1.07. Grassland apparently mainta ins only slightly higher soil C levels than the bare land. On average, degradation index of so il following forest clearance was 35% with the highest deterioration occurred in the bare land (38%. Fallowing the fields by naturally growth of Imperata cylindrica for about 15 yr in abandoned land after 3-5 years of cultivation did not improve the soil quality. Moreover, forest clearance has an impact on soil quality as resulted in the loss of a physically protected organic matter and reduction in some labile C pools, thus declined biological activity at disturbed

Migration and bioavailability of 137Cs in forest soil of southern Germany

International Nuclear Information System (INIS)

Konopleva, I.; Klemt, E.; Konoplev, A.; Zibold, G.

2009-01-01

To give a quantitative description of the radiocaesium soil-plant transfer for fern (Dryopteris carthusiana) and blackberry (Rubus fruticosus), physical and chemical properties of soils in spruce and mixed forest stands were investigated. Of special interest was the selective sorption of radiocaesium, which was determined by measuring the Radiocaesium Interception Potential (RIP). Forest soil and plants were taken at 10 locations of the Altdorfer Wald (5 sites in spruce forest and 5 sites in mixed forest). It was found that the bioavailability of radiocaesium in spruce forest was on average seven times higher than in mixed forest. It was shown that important factors determining the bioavailability of radiocaesium in forest soil were its exchangeability and the radiocaesium interception potential (RIP) of the soil. Low potassium concentration in soil solution of forest soils favors radiocaesium soil-plant transfer. Ammonium in forest soils plays an even more important role than potassium as a mobilizer of radiocaesium. The availability factor - a function of RIP, exchangeability and cationic composition of soil solution - characterized reliably the soil-plant transfer in both spruce and mixed forest. For highly organic soils in coniferous forest, radiocaesium sorption at regular exchange sites should be taken into account when its bioavailability is considered

Nitrate and dissolved organic carbon mobilization in response to soil freezing variability

Science.gov (United States)

Colin B. Fuss; Charles T. Driscoll; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Timothy J. Fahey; Melany C. Fisk; Myron J. Mitchell; Pamela H. Templer; Jorge Durán; Jennifer L. Morse

2016-01-01

Reduced snowpack and associated increases in soil freezing severity resulting from winter climate change have the potential to disrupt carbon (C) and nitrogen (N) cycling in soils. We used a natural winter climate gradient based on elevation and aspect in a northern hardwood forest to examine the effects of variability in soil freezing depth, duration, and frequency on...

Trophic conditions of forest soils of the Pieniny National Park, southern Poland

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Wanic Tomasz

2017-12-01

Full Text Available The primary objective of this study was to characterise the edaphic conditions of forest areas in the Pieniny National Park (PNP, and to describe the dependencies between properties of forest soils and types of forest plant communities. The “Soil Trophic Index” (SIGg for mountainous areas was applied. The evaluation of the trophism for 74 forest monitoring employed the soil trophic index for mountainous areas SIGg or SIGgo. Plant communities in the forest monitoring areas were classified according to the Braun-Blanquet’s phytosociological method. Soils of PNP present in the forest monitoring areas were mostly classified as eutrophic brown soils (72.9%, rendzinas (10.8%, brown rendzinas (5.41%, and rubble initial soils (5.41%. Pararendzinas, dystrophic brown soils, and gley soils were less common (total below 5.5%. In the forest monitoring areas of PNP, eutrophic soils predominate over mesotrophic soils. High SIGg index of the soils is caused by high values of acidity and nitrogen content. The Carpathian beech forest Dentario glandulosae-Fagetum and thermophilic beech forest Carici albae-Fagetum associations are characterised by high naturalness and compatibility of theoretical habitats. The soils of the Carpathian fir forest Dentario glandulosae-Fagetum abietetosum subcommunity is characterised by a higher share of silt and clay particles and lower acidity as compared to the Carpathian beech forest Dentario glandulosae-Fagetum typicum subcommunity. The soils of the forest monitoring areas in PNP stand out in terms of their fertility against forest soils in other mountainous areas in Poland.

Earthworm effects on the incorporation of litter C and N into soil organic matter in a sugar maple forest.

Science.gov (United States)

Fahey, Timothy J; Yavitt, Joseph B; Sherman, Ruth E; Maerz, John C; Groffman, Peter M; Fisk, Melany C; Bohlen, Patrick J

2013-07-01

To examine the mechanisms of earthworm effects on forest soil C and N, we double-labeled leaf litter with 13C and 15N, applied it to sugar maple forest plots with and without earthworms, and traced isotopes into soil pools. The experimental design included forest plots with different earthworm community composition (dominated by Lumbricus terrestris or L. rubellus). Soil carbon pools were 37% lower in earthworm-invaded plots largely because of the elimination of the forest floor horizons, and mineral soil C:N was lower in earthworm plots despite the mixing of high C:N organic matter into soil by earthworms. Litter disappearance over the first winter-spring was highest in the L. terrestris (T) plots, but during the warm season, rapid loss of litter was observed in both L. rubellus (R) and T plots. After two years, 22.0% +/- 5.4% of 13C released from litter was recovered in soil with no significant differences among plots. Total recovery of added 13C (decaying litter plus soil) was much higher in no-worm (NW) plots (61-68%) than in R and T plots (20-29%) as much of the litter remained in the former whereas it had disappeared in the latter. Much higher percentage recovery of 15N than 13C was observed, with significantly lower values for T than R and NW plots. Higher overwinter earthworm activity in T plots contributed to lower soil N recovery. In earthworm-invaded plots isotope enrichment was highest in macroaggregates and microaggregates whereas in NW plots silt plus clay fractions were most enriched. The net effect of litter mixing and priming of recalcitrant soil organic matter (SOM), stabilization of SOM in soil aggregates, and alteration of the soil microbial community by earthworm activity results in loss of SOM and lowering of the C:N ratio. We suggest that earthworm stoichiometry plays a fundamental role in regulating C and N dynamics of forest SOM.

Soil heat flux measurements in an open forest

NARCIS (Netherlands)

vanderMeulen, MJW; Klaassen, W; Kiely, G

1996-01-01

The soil surface heat flux in an open oak forest was determined at four locations to account for the heterogeneity of the forest. Soil temperatures and soil water content were measured at several depths and an integration method with three layers was used. The thickness of the bottom layer was

Soil Heat Flux Measurements in an Open Forest

NARCIS (Netherlands)

Meulen, M.W.J. van der; Klaassen, W.

1996-01-01

The soil surface heat flux in an open oak forest was determined at four locations to account for the heterogeneity of the forest. Soil temperatures and soil water content were measured at several depths and an integration method with three layers was used. The thickness of the bottom layer was

VARIABILITY OF ARABLE AND FOREST SOILS PROPERTIES ON ERODED SLOPES

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Paweł Wiśniewski

2014-10-01

Full Text Available The basic method of reducing soil and land erosion is a change of land use, for example, from arable to forest. Particularly effective as a protective role – according to the Polish law – soil-protecting forests. The thesis presents differences in the deformation of the basic soil properties on moraine slopes, depending on land use. There has been presented the function and the efficiency of the soil-protecting forests in erosion control. The soil cross section transects and soil analysis displayed that soil-protecting forests are making an essential soil cover protection from degradation, inter alia, limiting the decrease of humus content, reduction of upper soil horizons and soil pedons layer. On the afforested slopes it was stated some clear changes of grain size and chemical properties of soils in relation to adjacent slopes agriculturally used.

Acid-base status and changes in Swedish forest soils

International Nuclear Information System (INIS)

Karltun, Erik; Stendahl, Johan; Lundin, Lars

2003-01-01

In this paper we use data from the Swedish National Survey of Forest Soils and Vegetation (NSFSV) to evaluate the present acid-base status of forest soils to try to answer the following questions. Which role do anthropogenic and biological acidification play for the present acid-base status of the soil profile? What is the present acid-base status of Swedish forest soils and how large areas may be considered as severely acidified? Do the current tendencies in soil acid-base status correspond with the positive development in surface waters?

Advances of study on atmospheric methane oxidation (consumption) in forest soil

Institute of Scientific and Technical Information of China (English)

WANG Chen-rui; SHI Yi; YANG Xiao-ming; WU Jie; YUE Jin

2003-01-01

Next to CO2, methane (CH4) is the second important contributor to global warming in the atmosphere and global atmospheric CH4 budget depends on both CH4 sources and sinks. Unsaturated soil is known as a unique sink for atmospheric CH4 in terrestrial ecosystem. Many comparison studies proved that forest soil had the biggest capacity of oxidizing atmospheric CH4 in various unsaturated soils. However, up to now, there is not an overall review in the aspect of atmospheric CH4 oxidation (consumption) in forest soil. This paper analyzed advances of studies on the mechanism of atmospheric CH4 oxidation, and related natural factors (Soil physical and chemical characters, temperature and moisture, ambient main greenhouse gases concentrations, tree species, and forest fire) and anthropogenic factors (forest clear-cutting and thinning, fertilization, exogenous aluminum salts and atmospheric deposition, adding biocides, and switch of forest land use) in forest soils. It was believed that CH4 consumption rate by forest soil was limited by diffusion and sensitive to changes in water status and temperature of soil. CH4 oxidation was also particularly sensitive to soil C/N, Ambient CO2, CH4 and N2O concentrations, tree species and forest fire. In most cases, anthropogenic disturbances will decrease atmospheric CH4 oxidation, thus resulting in the elevating of atmospheric CH4. Finally, the author pointed out that our knowledge of atmospheric CH4 oxidation (consumption) in forest soil was insufficient. In order to evaluate the contribution of forest soils to atmospheric CH4 oxidation and the role of forest played in the process of global environmental change, and to forecast the trends of global warming exactly, more researchers need to studies further on CH4 oxidation in various forest soils of different areas.

Soil does not explain monodominance in a Central African tropical forest.

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Kelvin S-H Peh

2011-02-01

Full Text Available Soil characteristics have been hypothesised as one of the possible mechanisms leading to monodominance of Gilbertiodendron dewerei in some areas of Central Africa where higher-diversity forest would be expected. However, the differences in soil characteristics between the G. dewevrei-dominated forest and its adjacent mixed forest are still poorly understood. Here we present the soil characteristics of the G. dewevrei forest and quantify whether soil physical and chemical properties in this monodominant forest are significantly different from the adjacent mixed forest.We sampled top soil (0-5, 5-10, 10-20, 20-30 cm and subsoil (150-200 cm using an augur in 6 × 1 ha areas of intact central Africa forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450-800 m apart, all chosen to be topographically homogeneous. Analysis--subjected to Bonferroni correction procedure--revealed no significant differences between the monodominant and mixed forests in terms of soil texture, median particle size, bulk density, pH, carbon (C content, nitrogen (N content, C:N ratio, C:total NaOH-extractable P ratio and concentrations of labile phosphorous (P, inorganic NaOH-extractable P, total NaOH-extractable P, aluminium, barium, calcium, copper, iron, magnesium, manganese, molybdenum, nickel, potassium, selenium, silicon, sodium and zinc. Prior to Bonferroni correction procedure, there was a significant lower level of silicon concentration found in the monodominant than mixed forest deep soil; and a significant lower level of nickel concentration in the monodominant than mixed forest top soil. Nevertheless, these were likely to be the results of multiple tests of significance.Our results do not provide clear evidence of soil mediation for the location of monodominant forests in relation to adjacent mixed forests. It is also likely that G. dewevrei does not influence soil chemistry in the monodominant forests.

Soil does not explain monodominance in a Central African tropical forest.

Science.gov (United States)

Peh, Kelvin S-H; Sonké, Bonaventure; Lloyd, Jon; Quesada, Carlos A; Lewis, Simon L

2011-02-10

Soil characteristics have been hypothesised as one of the possible mechanisms leading to monodominance of Gilbertiodendron dewerei in some areas of Central Africa where higher-diversity forest would be expected. However, the differences in soil characteristics between the G. dewevrei-dominated forest and its adjacent mixed forest are still poorly understood. Here we present the soil characteristics of the G. dewevrei forest and quantify whether soil physical and chemical properties in this monodominant forest are significantly different from the adjacent mixed forest. We sampled top soil (0-5, 5-10, 10-20, 20-30 cm) and subsoil (150-200 cm) using an augur in 6 × 1 ha areas of intact central Africa forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450-800 m apart), all chosen to be topographically homogeneous. Analysis--subjected to Bonferroni correction procedure--revealed no significant differences between the monodominant and mixed forests in terms of soil texture, median particle size, bulk density, pH, carbon (C) content, nitrogen (N) content, C:N ratio, C:total NaOH-extractable P ratio and concentrations of labile phosphorous (P), inorganic NaOH-extractable P, total NaOH-extractable P, aluminium, barium, calcium, copper, iron, magnesium, manganese, molybdenum, nickel, potassium, selenium, silicon, sodium and zinc. Prior to Bonferroni correction procedure, there was a significant lower level of silicon concentration found in the monodominant than mixed forest deep soil; and a significant lower level of nickel concentration in the monodominant than mixed forest top soil. Nevertheless, these were likely to be the results of multiple tests of significance. Our results do not provide clear evidence of soil mediation for the location of monodominant forests in relation to adjacent mixed forests. It is also likely that G. dewevrei does not influence soil chemistry in the monodominant forests.

Isotope geochemistry of sulfur in forest soils and in new groundwater below forest soils

International Nuclear Information System (INIS)

Mayer, B.

1993-04-01

The isotope geochemistry of sulphur in aerobic forest soils and new groundwater below forest soils was investigated for the purpose of investigating the transport and transformation behaviour of sulfate in the water-unsaturated zone. The effects of hydrodynamic and biogeochemical processes on the development of seepage water sulfate isotopes between depositions and groundwater were investigated by means of laboratory experiments, profile studies, lysimeter experiments, and field studies in order to determine the sulphur conversion processes. Dissolved sulphur from precipitates, seepage water, creek water and groundwater, as well as sulphur extracted from soil samples, were precipitated in the form of BaSO 4 or AgS 2 , decomposed thermally into SO 2 or CO 2 , and the 34 S/ 32 S and 18 O/ 16 O isotope ratios were determined by mass spectrometry. (orig.) [de

Soil-plant transfer factors in forest ecosystems

International Nuclear Information System (INIS)

Strebl, F.; Gerzabek, M.H.

1995-04-01

Within scope of an extended study about 137 Cs behaviour in forest ecosystems several parameters were found to influence soil-plant transfer factors. TF-values of different plant species cover a range of two magnitudes. This is partly due to variations in rooting depth of plants and specific physiological adaptations of nutrient supply. Perrenial plants like trees (Picea abies) and dwarf shrubs (Vaccinium myrtillus) showed a distinct age - dependency of 137 Cs - transfer factors. In young plant parts caesium concentration is higher than in old, more signified twigs. A correlation analysis of physico-chemical soil parameters and TF-values to forest vegetation showed, that soil organic matter, especially the degree of humification and the ratio between extractable fulvic to humic acids are important influencing factors of 137 Cs transfer from forest soils to plants. (author)

Soil Quality Index Determination Models for Restinga Forest

Science.gov (United States)

Bonilha, R. M.; Casagrande, J. C.; Soares, R. M.

2012-04-01

The Restinga Forest is a set of plant communities in mosaic, determined by the characteristics of their substrates as a result of depositional processes and ages. In this complex mosaic are the physiognomies of restinga forests of high-stage regeneration (high restinga) and middle stage of regeneration (low restinga), each with its plant characteristics that differentiate them. Located on the coastal plains of the Brazilian coast, suffering internal influences both the continental slopes, as well as from the sea. Its soils come from the Quaternary and are subject to constant deposition of sediments. The climate in the coastal type is tropical (Köppen). This work was conducted in four locations: (1) Anchieta Island, Ubatuba, (2) Juréia-Itatins Ecological Station, Iguape, (3) Vila das Pedrinhas, Comprida Island; and (4) Cardoso Island, Cananeia. The soil samples were collect at a depths of 0 to 5, 0-10, 0-20, 20-40 and 40 to 60cm for the chemical and physical analysis. Were studied the additive and pondering additive models to evaluate soil quality. It was concluded: a) the comparative additive model produces quantitative results and the pondering additive model quantitative results; b) as the pondering additive model, the values of Soil Quality Index (SQI) for soils under forest of restinga are low and realistic, demonstrating the small plant biomass production potential of these soils, as well as their low resilience; c) the values of SQI similar to areas with and without restinga forest give quantitative demonstration of the restinga be considered as soil phase; d) restinga forest, probably, is maintained solely by the cycling of nutrients in a closed nutrient cycling; e) for the determination of IQS for soils under restinga vegetation the use of routine chemical analysis is adequate. Keywords: Model, restinga forest, Soil Quality Index (SQI).

Forest harvesting reduces the soil metagenomic potential for biomass decomposition.

Science.gov (United States)

Cardenas, Erick; Kranabetter, J M; Hope, Graeme; Maas, Kendra R; Hallam, Steven; Mohn, William W

2015-11-01

Soil is the key resource that must be managed to ensure sustainable forest productivity. Soil microbial communities mediate numerous essential ecosystem functions, and recent studies show that forest harvesting alters soil community composition. From a long-term soil productivity study site in a temperate coniferous forest in British Columbia, 21 forest soil shotgun metagenomes were generated, totaling 187 Gb. A method to analyze unassembled metagenome reads from the complex community was optimized and validated. The subsequent metagenome analysis revealed that, 12 years after forest harvesting, there were 16% and 8% reductions in relative abundances of biomass decomposition genes in the organic and mineral soil layers, respectively. Organic and mineral soil layers differed markedly in genetic potential for biomass degradation, with the organic layer having greater potential and being more strongly affected by harvesting. Gene families were disproportionately affected, and we identified 41 gene families consistently affected by harvesting, including families involved in lignin, cellulose, hemicellulose and pectin degradation. The results strongly suggest that harvesting profoundly altered below-ground cycling of carbon and other nutrients at this site, with potentially important consequences for forest regeneration. Thus, it is important to determine whether these changes foreshadow long-term changes in forest productivity or resilience and whether these changes are broadly characteristic of harvested forests.

Occurrence of culturable soil fungi in a tropical moist deciduous forest Similipal Biosphere Reserve, Odisha, India.

Science.gov (United States)

Jena, Santanu K; Tayung, Kumanand; Rath, Chandi C; Parida, Debraj

2015-03-01

Similipal Biosphere Reserve (SBR) is a tropical moist deciduous forest dominated by the species Shorea robusta . To the best of our knowledge their rich biodiversity has not been explored in term of its microbial wealth. In the present investigation, soil samples were collected from ten selected sites inside SBR and studied for their physicochemical parameters and culturable soil fungal diversity. The soil samples were found to be acidic in nature with a pH ranging from of 5.1-6.0. Highest percentage of organic carbon and moisture content were observed in the samples collected from the sites, Chahala-1 and Chahala-2. The plate count revealed that fungal population ranged from 3.6 × 10 (4) -2.1 × 10 (5) and 5.1 × 10 (4) -4.7 × 10 (5) cfu/gm of soil in summer and winter seasons respectively. The soil fungus, Aspergillus niger was found to be the most dominant species and Species Important Values Index (SIVI) was 43.4 and 28.6 in summer and winter seasons respectively. Among the sites studied, highest fungal diversity indices were observed during summer in the sites, Natto-2 and Natto-1. The Shannon-Wiener and Simpson indices in these two sites were found to be 3.12 and 3.022 and 0.9425 and 0.9373 respectively. However, the highest Fisher's alpha was observed during winter in the sites Joranda, Natto-2, Chahala-1 and Natto-1 and the values were 3.780, 3.683, 3.575 and 3.418 respectively. Our investigation revealed that, fungal population was dependent on moisture and organic carbon (%) of the soil but its diversity was found to be regulated by sporulating species like Aspergillus and Penicillium.

Occurrence of culturable soil fungi in a tropical moist deciduous forest Similipal Biosphere Reserve, Odisha, India

Science.gov (United States)

Jena, Santanu K.; Tayung, Kumanand; Rath, Chandi C.; Parida, Debraj

2015-01-01

Similipal Biosphere Reserve (SBR) is a tropical moist deciduous forest dominated by the species Shorea robusta . To the best of our knowledge their rich biodiversity has not been explored in term of its microbial wealth. In the present investigation, soil samples were collected from ten selected sites inside SBR and studied for their physicochemical parameters and culturable soil fungal diversity. The soil samples were found to be acidic in nature with a pH ranging from of 5.1–6.0. Highest percentage of organic carbon and moisture content were observed in the samples collected from the sites, Chahala-1 and Chahala-2. The plate count revealed that fungal population ranged from 3.6 × 10 4 –2.1 × 10 5 and 5.1 × 10 4 –4.7 × 10 5 cfu/gm of soil in summer and winter seasons respectively. The soil fungus, Aspergillus niger was found to be the most dominant species and Species Important Values Index (SIVI) was 43.4 and 28.6 in summer and winter seasons respectively. Among the sites studied, highest fungal diversity indices were observed during summer in the sites, Natto-2 and Natto-1. The Shannon-Wiener and Simpson indices in these two sites were found to be 3.12 and 3.022 and 0.9425 and 0.9373 respectively. However, the highest Fisher’s alpha was observed during winter in the sites Joranda, Natto-2, Chahala-1 and Natto-1 and the values were 3.780, 3.683, 3.575 and 3.418 respectively. Our investigation revealed that, fungal population was dependent on moisture and organic carbon (%) of the soil but its diversity was found to be regulated by sporulating species like Aspergillus and Penicillium . PMID:26221092

Occurrence of culturable soil fungi in a tropical moist deciduous forest Similipal Biosphere Reserve, Odisha, India

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Santanu K. Jena

2015-03-01

Full Text Available Similipal Biosphere Reserve (SBR is a tropical moist deciduous forest dominated by the species Shorea robusta. To the best of our knowledge their rich biodiversity has not been explored in term of its microbial wealth. In the present investigation, soil samples were collected from ten selected sites inside SBR and studied for their physicochemical parameters and culturable soil fungal diversity. The soil samples were found to be acidic in nature with a pH ranging from of 5.1–6.0. Highest percentage of organic carbon and moisture content were observed in the samples collected from the sites, Chahala-1 and Chahala-2. The plate count revealed that fungal population ranged from 3.6 × 104–2.1 × 105 and 5.1 × 104–4.7 × 105 cfu/gm of soil in summer and winter seasons respectively. The soil fungus, Aspergillus niger was found to be the most dominant species and Species Important Values Index (SIVI was 43.4 and 28.6 in summer and winter seasons respectively. Among the sites studied, highest fungal diversity indices were observed during summer in the sites, Natto-2 and Natto-1. The Shannon-Wiener and Simpson indices in these two sites were found to be 3.12 and 3.022 and 0.9425 and 0.9373 respectively. However, the highest Fisher’s alpha was observed during winter in the sites Joranda, Natto-2, Chahala-1 and Natto-1 and the values were 3.780, 3.683, 3.575 and 3.418 respectively. Our investigation revealed that, fungal population was dependent on moisture and organic carbon (% of the soil but its diversity was found to be regulated by sporulating species like Aspergillus and Penicillium.

Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

Science.gov (United States)

Yang, Fan; Wang, Yong; Chan, Zhulong

2014-01-01

The establishment of riparian protection forests in the Three Gorges Reservoir (TGR) is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ). Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides) and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora) might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress and recover well

Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

Directory of Open Access Journals (Sweden)

Fan Yang

Full Text Available The establishment of riparian protection forests in the Three Gorges Reservoir (TGR is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ. Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress

Soil-pit Method for Distribution and Leaching Loss of Nitrogen in Winter Wheat’s Soil, Weishan Irrigation District

Science.gov (United States)

Zhao, Erni; Xu, Lirong; Wang, Rongzhen

2018-01-01

Unreasonable application of irrigation and fertilizer will cause the waste of water and nitrogen and environmental pollution. In this paper, a series of soil-pit experiments were carried out to study the distribution and leaching loss of nitrogen in winter wheat’s soil. The results showed that NO3 - concentration at 20-80cm depth mainly responded to fertilizer application at the beginning of field experiment, but the amount of irrigation became the dominant factor with the growth of winter wheat. It is noteworthy that the distribution of NO3 - was mainly affected by the amount of fertilizer applied at the depth of 120-160cm in the whole period of growth of winter wheat. The accumulation position of NH4 + was deepened as the amount of irrigation increased, however, the maximum aggregation depth of ammonium nitrogen was no more than 80cm owing to its poor migration. It can be concluded that the influence of irrigation amount on the concentration of NH4 + in soil solution was more obvious than that of fertilizer. Compared with fertilizer, the amount of irrigation played a leading role in the utilization ratio of nitrogen and the yield of winter wheat. In summary, the best water and fertilizer treatment occurred in No.3 soil-pit, which meant that the middle amount of water and fertilizer could get higher wheat yield and less nitrogen leaching losses in the study area.

Modelling trends in soil solution concentrations under five forest-soil combinations in the Netherlands

NARCIS (Netherlands)

Salm, van der C.; Vries, de W.; Kros, J.

1996-01-01

The influence of forest and soil properties on changes in soil solution concentration upon a reduction deposition was examined for five forest-soil combinations with the dynamic RESAM model. Predicted concentrations decreased in the direction Douglas fir - Scotch pine - oak, due to decreased

Effects of forest conversion on soil microbial communities depend on soil layer on the eastern Tibetan Plateau of China.

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Ruoyang He

Full Text Available Forest land-use changes have long been suggested to profoundly affect soil microbial communities. However, how forest type conversion influences soil microbial properties remains unclear in Tibetan boreal forests. The aim of this study was to explore variations of soil microbial profiles in the surface organic layer and subsurface mineral soil among three contrasting forests (natural coniferous forest, NF; secondary birch forest, SF and spruce plantation, PT. Soil microbial biomass, activity and community structure of the two layers were investigated by chloroform fumigation, substrate respiration and phospholipid fatty acid analysis (PLFA, respectively. In the organic layer, both NF and SF exhibited higher soil nutrient levels (carbon, nitrogen and phosphorus, microbial biomass carbon and nitrogen, microbial respiration, PLFA contents as compared to PT. However, the measured parameters in the mineral soils often did not differ following forest type conversion. Irrespective of forest types, the microbial indexes generally were greater in the organic layer than in the mineral soil. PLFAs biomarkers were significantly correlated with soil substrate pools. Taken together, forest land-use change remarkably altered microbial community in the organic layer but often did not affect them in the mineral soil. The microbial responses to forest land-use change depend on soil layer, with organic horizons being more sensitive to forest conversion.

Seasonal Belowground Ecosystem and Eco-enzymatic Responses to Soil pH and Phosphorus Availability in Temperate Hardwood Forests

Science.gov (United States)

Smemo, K. A.; Deforest, J. L.; Petersen, S. L.; Burke, D.; Hewins, C.; Kluber, L. A.; Kyker, S. R.

2013-12-01

Atmospheric acid deposition can increase phosphorus (P) limitation in temperate hardwood forests by increasing N availability, and therefore P demand, and/or by decreasing pH and occluding inorganic P. However, only recently have studies demonstrated that P limitation can occur in temperate forests and very little is known about the temporal aspects of P dynamics in acidic forest soils and how seasonal shifts in nutrient availability and demand influence microbial investment in extracellular enzymes. The objectives of this study were to investigate how P availability and soil pH influence seasonal patterns of nutrient cycling and soil microbial activity in hardwood forests that experience chronic acid deposition. We experimentally manipulated soil pH, P, or both for three years and examined soil treatment responses in fall, winter, spring, early summer, and late summer. We found that site (glaciated versus unglaciated) and treatment had the most significant influence on nutrient pools and cycling. In general, nutrient pools were higher in glaciated soils than unglaciated for measured nutrients, including total C and N (2-3 times higher), extractable inorganic nitrogen, and readily available P. Treatment had no impact on total C and N pools in either region, but did affect other measured nutrients such as ammonium, which was greatest in the elevated pH treatment for both sites. As expected, readily available P pools were highest in the elevated P treatments (3 fold increase in both sites), but raising pH decreased available P pools in the glaciated site. Raising soil pH increased both net N mineralization rates and net P mineralization rates, regardless of site. Nitrification responses were complex, but we observed an overall significant nitrification increase under elevated pH, particularly in the growing season. Extracellular enzyme activity showed more seasonal patterns than site and treatment effects, exhibiting significant growing season activity reductions for

Winter climate change and fine root biogenic silica in sugar maple trees (Acer saccharum): Implications for silica in the Anthropocene

Science.gov (United States)

Maguire, Timothy J.; Templer, Pamela H.; Battles, John J.; Fulweiler, Robinson W.

2017-03-01

Winter temperatures are projected to increase over the next century, leading to reductions in winter snowpack and increased frequency of soil freezing in many northern forest ecosystems. Here we examine biogenic silica (BSi) concentrations in sugar maple (Acer saccharum) fine roots collected from a snow manipulation experiment at Hubbard Brook Experimental Forest (New Hampshire, USA). Increased soil freezing significantly lowered the BSi content of sugar maple fine roots potentially decreasing their capacity to take up water and dissolved nutrients. The reduced silica uptake (8 ± 1 kmol silica km-2) by sugar maple fine roots is comparable to silica export from temperate forest watersheds. We estimate that fine roots account for 29% of sugar maple BSi, despite accounting for only 4% of their biomass. These results suggest that increased frequency of soil freezing will reduce silica uptake by temperate tree roots, thereby changing silica availability in downstream receiving waters.

Stress tolerance of soil fungal communities from native Atlantic forests, reforestations, and a sand mining degraded area.

Science.gov (United States)

Ferreira, Paulo C; Pupin, Breno; Rangel, Drauzio E N

2018-06-01

Microorganisms are essential to the functionality of the soil, particularly in organic matter decomposition and nutrient cycling, which regulate plant productivity and shape the soil structure. However, biotic and abiotic stresses greatly disrupt soil fungal communities and, thereby, disturb the ecosystem. This study quantified seasonal tolerances to UV-B radiation and heat of fungal communities, which could be cultured, found in soil from two native Atlantic forest fragments called F1 and F2, five reforested areas (RA) planted in 1994, 1997, 2004, 2007, and 2009 with native species of the Atlantic forest, and one sand mining degraded soil (SMDS). The cold activity of the soil fungal communities (FC) from the eight different areas was also studied. Higher tolerance to UV-B radiation and heat was found in the FC from the SMDS and the 2009RA, where the incidence of heat and UV radiation from sun was more intense, which caused selection for fungal taxa that were more UV-B and heat tolerant in those areas. Conversely, the FC from the native forests and older reforested sites were very susceptible to heat and UV-B radiation. The cold activity of the soil FC from different areas of the study showed an erratic pattern of responses among the sampling sites. Little difference in tolerance to UV-B radiation and heat was found among the FC of soil samples collected in different seasons; in general soil FC collected in winter were less tolerant to UV-B radiation, but not for heat. In conclusion, FC from SMDS soil that receive intense heat and UV radiation, as well as with low nutrient availability, were more tolerant to both UV-B radiation and heat. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Energy balance of a sparse coniferous high-latitude forest under winter conditions

NARCIS (Netherlands)

Gryning, S.E.; Batchvarova, E.; DeBruin, H.A.R.

2001-01-01

Measurements carried out in Northern Finland on radiation and turbulent fluxes over a sparse, sub-arctic boreal forest with snow covered ground were analysed. The measurements represent late winter conditions characterised by low solar elevation angles. During the experiment (12-24 March 1997) day

The impact of nitrogen deposition on carbon sequestration in European forests and forest soils

DEFF Research Database (Denmark)

de Vries, Wim; Reinds, Gert Jan; Gundersen, Per

2006-01-01

for CO2 emissions because of harvest and forest fires, was assumed 33% of the overall C pool changes by growth. C sequestration in the soil were based on calculated nitrogen (N) retention (N deposition minus net N uptake minus N leaching) rates in soils, multiplied by the C/N ratio of the forest soils......An estimate of net carbon (C) pool changes and long-term C sequestration in trees and soils was made at more than 100 intensively monitored forest plots (level II plots) and scaled up to Europe based on data for more than 6000 forested plots in a systematic 16 km x 16 km grid (level I plots). C...... pool changes in trees at the level II plots were based on repeated forest growth surveys At the level I plots, an estimate of the mean annual C pool changes was derived from stand age and available site quality characteristics. C sequestration, being equal to the long-term C pool changes accounting...

Winter survival of microbial contaminants in soil: an in situ verification.

Science.gov (United States)

Bucci, Antonio; Allocca, Vincenzo; Naclerio, Gino; Capobianco, Giovanni; Divino, Fabio; Fiorillo, Francesco; Celico, Fulvio

2015-01-01

The aim of the research was to evaluate, at site scale, the influence of freezing and freeze/thaw cycles on the survival of faecal coliforms and faecal enterococci in soil, in a climate change perspective. Before the winter period and during grazing, viable cells of faecal coliforms and faecal enterococci were detected only in the first 10 cm below ground, while, after the winter period and before the new seasonal grazing, a lower number of viable cells of both faecal indicators was detected only in some of the investigated soil profiles, and within the first 5 cm. Taking into consideration the results of specific investigations, we hypothesise that the non-uniform spatial distribution of grass roots within the studied soil can play an important role in influencing this phenomenon, while several abiotic factors do not play any significant role. Taking into account the local trend in the increase of air temperature, a different distribution of microbial pollution over time is expected in spring waters, in future climate scenarios. The progressive increase in air temperature will cause a progressive decrease in freeze/thaw cycles at higher altitudes, minimising cold shocks on microbial cells, and causing spring water pollution also during winter. Copyright © 2014. Published by Elsevier B.V.

Migration and bioavailability of {sup 137}Cs in forest soil of southern Germany

Energy Technology Data Exchange (ETDEWEB)

Konopleva, I.; Klemt, E. [Hochschule Ravensburg-Weingarten, University of Applied Sciences, 88250 Weingarten (Germany); Konoplev, A. [Scientific Production Association ' TYPHOON' , Obninsk (Russian Federation); Zibold, G. [Hochschule Ravensburg-Weingarten, University of Applied Sciences, 88250 Weingarten (Germany)], E-mail: zibold@hs-weingarten.de

2009-04-15

To give a quantitative description of the radiocaesium soil-plant transfer for fern (Dryopteris carthusiana) and blackberry (Rubus fruticosus), physical and chemical properties of soils in spruce and mixed forest stands were investigated. Of special interest was the selective sorption of radiocaesium, which was determined by measuring the Radiocaesium Interception Potential (RIP). Forest soil and plants were taken at 10 locations of the Altdorfer Wald (5 sites in spruce forest and 5 sites in mixed forest). It was found that the bioavailability of radiocaesium in spruce forest was on average seven times higher than in mixed forest. It was shown that important factors determining the bioavailability of radiocaesium in forest soil were its exchangeability and the radiocaesium interception potential (RIP) of the soil. Low potassium concentration in soil solution of forest soils favors radiocaesium soil-plant transfer. Ammonium in forest soils plays an even more important role than potassium as a mobilizer of radiocaesium. The availability factor - a function of RIP, exchangeability and cationic composition of soil solution - characterized reliably the soil-plant transfer in both spruce and mixed forest. For highly organic soils in coniferous forest, radiocaesium sorption at regular exchange sites should be taken into account when its bioavailability is considered.

Differential controls on soil carbon density and mineralization among contrasting forest types in a temperate forest ecosystem

Science.gov (United States)

You, Ye-Ming; Wang, Juan; Sun, Xiao-Lu; Tang, Zuo-Xin; Zhou, Zhi-Yong; Sun, Osbert Jianxin

2016-01-01

Understanding the controls on soil carbon dynamics is crucial for modeling responses of ecosystem carbon balance to global change, yet few studies provide explicit knowledge on the direct and indirect effects of forest stands on soil carbon via microbial processes. We investigated tree species, soil, and site factors in relation to soil carbon density and mineralization in a temperate forest of central China. We found that soil microbial biomass and community structure, extracellular enzyme activities, and most of the site factors studied varied significantly across contrasting forest types, and that the associations between activities of soil extracellular enzymes and microbial community structure appeared to be weak and inconsistent across forest types, implicating complex mechanisms in the microbial regulation of soil carbon metabolism in relation to tree species. Overall, variations in soil carbon density and mineralization are predominantly accounted for by shared effects of tree species, soil, microclimate, and microbial traits rather than the individual effects of the four categories of factors. Our findings point to differential controls on soil carbon density and mineralization among contrasting forest types and highlight the challenge to incorporate microbial processes for constraining soil carbon dynamics in global carbon cycle models. PMID:26925871

Mineral Soil Carbon in Managed Hardwood Forests of the Northeastern US

Science.gov (United States)

Vario, C.; Friedland, A.; Hornig, C.

2013-12-01

New England is characterized by extensive forest cover and large reservoirs of soil carbon (C). In northern hardwood forests, mineral soil C can account for up to 50% of total ecosystem C. There has been an increasing demand for forests to serve both as a C sink and a renewable energy source, and effective management of the ecosystem C balance relies on accurate modeling of each compartment of the ecosystem. However, the dynamics of soil C storage with respect to forest use are variable and poorly understood, particularly in mineral soils. For example, current regional models assume C pools after forest harvesting do not change, while some studies suggest that belowground mineral soil C pools can be affected by disturbances at the soil surface. We quantified mineral soil C pools in previously clear-cut stands in seven research or protected forests across New York, New Hampshire, Massachusetts, and Vermont. The ages of the sites sampled ranged from recently cleared to those with no disturbance history, with 21 forest stands represented in the study. Within each research forest studied, physical parameters such as soil type, forest type, slope and land-use history (aside from forest harvest) did not vary between the stands of different ages. Soil samples were collected to a depth of 60 cm below the mineral-organic boundary using a gas-powered augur and 9.5-cm diameter drill bit. Samples were collected in 10-cm increments in shallow mineral soil and 15-cm increments from 30-60 cm depth. Carbon, nitrogen (N), pH, texture and soil mineralogy were measured across the regional sites. At Bartlett Experimental Forest (BEF) in New Hampshire, mineral soil biogeochemistry in cut and uncut sites was studied at a finer scale. Measurements included soil temperature to 55 cm depth, carbon compound analyses using Py-GCMS and soil microbial messenger RNA extractions from mineral soil. Finally, we simulated C dynamics after harvesting by building a model in Stella, with a particular

Effect of soil compaction and biomass removal on soil CO2 efflux in a Missouri forest

Science.gov (United States)

Felix, Jr. Ponder

2005-01-01

Forest disturbances associated with harvesting activities can affect soil properties and soil respiration. A soda-lime technique was used to measure soil carbon dioxide (CO2) efflux rates in clearcut plots of a Missouri oak-hickory (Quercus spp. L.-Carya spp. Nutt.) forest 4 years after being treated with two levels of forest...

Soil Organic Carbon Responses to Forest Expansion on Mountain Grasslands

DEFF Research Database (Denmark)

Guidi, Claudia

. Changes in labile soil C were assessed by carbohydrate and thermal analyses of soil samples and fractions. Forest expansion on mountain grasslands caused a decrease in SOC stocks within the mineral soil. The SOC accumulation within the organic layers following forest establishment could not fully...... and thermally labile to resistant components decreased from grassland to forest successional stages, and corresponded to decreased SOC protection within stable aggregates. This PhD thesis showed that mineral SOC stocks and physically protected SOC fractions decreased following forest expansion on mountain......Grassland abandonment followed by progressive forest expansion is the dominant land-use change in the European Alps. Contrasting trends in soil organic carbon (SOC) stocks have been reported for mountainous regions following forest expansion on grasslands. Moreover, its effects on SOC properties...

Bioecology of pear thrips: distribution in forest soils

Science.gov (United States)

Margaret Skinner; Bruce L. Parker

1991-01-01

The vertical and horizontal distribution of pear thrips in Vermont sugar maple forest soils was investigated. In the fall, about 86% of the thrips were found in the upper 10 cm of soil, though a few were found as deep as 20 cm. No thrips were found in the leaf litter. Soil sampling tools to determine thrips populations within an entire forest were tested and a standard...

Linkages between forest soils and water quality and quantity

Science.gov (United States)

Daniel G. Neary; George G. Ice; C. Rhett Jackson

2009-01-01

The most sustainable and best quality fresh water sources in the world originate in forest ecosystems. The biological, chemical, and physical characteristics of forest soils are particularly well suited to delivering high quality water to streams, moderating stream hydrology, and providing diverse aquatic habitat. Forest soils feature litter layers and...

Granulated wood ash to forest soil - Ecological effects

International Nuclear Information System (INIS)

Rosen, K.; Eriksson, H.; Clarholm, M.; Lundkvist, H.; Rudebeck, A.

1993-01-01

This report describes research concerning ecological effects of wood ash recycling to forest soils. The main part of the minerals in the wood fuels are retained in the ashes after combustion. By returning the ashes back to the cleared forest areas, the mineral losses can be reduced. Adding ashes and limestone is a method to vitalize acidified forest soils and restore the production capacity. 48 refs, 26 figs, 8 tabs

Coastal Plain Soil Fertility Degradation And Natural Forest Ecosystem Regeneration

Science.gov (United States)

Casagrande, J. C.; Sato, C. A.; Reis-Duarte, R. M.; Soares, M. R.; Galvão Bueno, M. S.

2009-04-01

The sand coastal plain vegetation (Restinga Forest) has been described as an ecosystem associated with the Atlantic Forest, constituted of mosaics, which occur in areas of great ecological diversity, particularly the features of the soil which mostly influence the forest, therefore assigned as edaphic community. The Restinga forest is one of the most fragile, showing low resilience to human damage This work was carried out in several points (14) of Restinga Forest (six low - trees from 3 to 10 m high - and eight high forest - trees from 10 to 15 m high) in the litoral coast of the state of São Paulo. Each sample was made of 15 subsamples of each area collected in each depth (one in 0 - 5, 5 - 10, 10 - 15, 15 - 20, and another in 0 - 20, 20 - 40, 40 and 60 cm). Soil characteristics analyzed were pH, P, Na, K, Ca, Mg, S, H + Al, Al, B, Cu, Fe, Mn, Zn contents and base saturation, cation exchange capacity and aluminum saturation. The vegetation physiognomies of Restinga forest (low and high) were associated with soil results and with the history of human occupation. The soils are sandy (2 to 4% of clay), resulting in a low capacity of nutrient retention. Soil fertility analysis to low and high Restinga forest were similar and showed very low contents of phosphorous, calcium and magnesium in all areas investigated. The base saturation was low due to low amounts of Na, K, Ca and Mg. Base saturation presents low level in all cases, less than 10, indicating low nutritional reserve in the soil. The aluminum saturation values varied from 58 to 69%. The level of calcium and magnesium were low in the subsurface soil layer mainly, associate with high aluminum saturation, representing an limiting factor for the root system development in depth. If soil fertility parameters do not show any significant difference between low and high Restinga physiognomy, what make distinction is the recuperation time. In the areas of high Forest can be note a too long time of recuperation

Sources of nitrous oxide emitted from European forest soils

DEFF Research Database (Denmark)

Ambus, P.; Zechmeister-Boltenstern, S.; Butterbach-Bahl, K.

2006-01-01

Forest ecosystems may provide strong sources of nitrous oxide (N2O), which is important for atmospheric chemical and radiative properties. Nonetheless, our understanding of controls on forest N2O emissions is insufficient to narrow current flux estimates, which still are associated with great...... uncertainties. In this study, we have investigated the quantitative and qualitative relationships between N-cycling and N2O production in European forests in order to evaluate the importance of nitrification and denitrification for N2O production. Soil samples were collected in 11 different sites characterized...... by variable climatic regimes and forest types. Soil N-cycling and associated production of N2O was assessed following application of 15N-labeled nitrogen. The N2O emission varied significantly among the different forest soils, and was inversely correlated to the soil C: N ratio. The N2O emissions were...

Radon levels and transport parameters in Atlantic Forest soils

International Nuclear Information System (INIS)

Farias, E.E.G. de; Silva Neto, P.C. da; Souza, E.M. de; De Franca, E.J.; Hazin, C.A.

2016-01-01

In natural forest soils, the radon transport processes can be significantly intensified due to the contribution of living organism activities to soil porosity. In this paper, the first results of the radon concentrations were obtained for soil gas from the Atlantic Forest, particularly in the Refugio Ecologico Charles Darwin, Brazil. The estimation of permeability and radon exhalation rate were carried out in this conservation unit. For forested soils, radon concentrations as high as 40 kBq m -3 were found. Based on the radon concentrations and on the permeability parameter, the results indicated considerable radon hazard for human occupation in the neighborhood. (author)

Carbon stocks in tree biomass and soils of German forests

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Wellbrock Nicole

2017-06-01

Full Text Available Close to one third of Germany is forested. Forests are able to store significant quantities of carbon (C in the biomass and in the soil. Coordinated by the Thünen Institute, the German National Forest Inventory (NFI and the National Forest Soil Inventory (NFSI have generated data to estimate the carbon storage capacity of forests. The second NFI started in 2002 and had been repeated in 2012. The reporting time for the NFSI was 1990 to 2006. Living forest biomass, deadwood, litter and soils up to a depth of 90 cm have stored 2500 t of carbon within the reporting time. Over all 224 t C ha-1 in aboveground and belowground biomass, deadwood and soil are stored in forests. Specifically, 46% stored in above-ground and below-ground biomass, 1% in dead wood and 53% in the organic layer together with soil up to 90 cm. Carbon stocks in mineral soils up to 30 cm mineral soil increase about 0.4 t C ha-1 yr-1 stocks between the inventories while the carbon pool in the organic layers declined slightly. In the living biomass carbon stocks increased about 1.0 t C ha-1 yr-1. In Germany, approximately 58 mill. tonnes of CO2 were sequestered in 2012 (NIR 2017.

Acidification of forest soil in Russia: From 1893 to present

Science.gov (United States)

Lapenis, A.G.; Lawrence, G.B.; Andreev, A.A.; Bobrov, A.A.; Torn, M.S.; Harden, J.W.

2004-01-01

It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term buffering capacity of nineteenth century forest soils developed on calcareous silt loam. In a chemical analysis comparing archived soils with modern soils collected from the same locations ???100 years later, we found varying degrees of forest-soil acidification in the taiga and forest steppe regions. Land-use history, increases in precipitation, and acidic deposition were contributing factors in acidification. The acidification of forest soil was documented through decreases in soil pH and changes in concentrations of exchangeable calcium and aluminum, which corresponded with changes in communities of soil microfauna. Although acidification was found at all three analyzed locations, the trends in soil chemistry were most pronounced where the highest loading of acidic deposition had taken place. Copyright 2004 by the American Geophysical Union.

Soil Water Improvements with the Long Term Use of a Winter Rye Cover Crop

Science.gov (United States)

Basche, A.; Kaspar, T.; Archontoulis, S.; Jaynes, D. B.; Sauer, T. J.; Parkin, T.; Miguez, F.

2015-12-01

The Midwestern United States, a region that produces one-third of maize and one-quarter of soybeans globally, is projected to experience increasing rainfall variability with future climate change. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance soil water storage, reducing the risks of flooding and runoff as well as drought-induced crop water stress. While some research indicates that a winter cover crop in a maize-soybean rotation increases soil water, producers continue to be concerned that water use by cover crops will reduce water for a following cash crop. We analyzed continuous in-field soil moisture measurements over from 2008-2014 at a Central Iowa research site that has included a winter rye cover crop in a maize-soybean rotation for thirteen years. This period of study included years in the top third of wettest years on record (2008, 2010, 2014) as well as years in the bottom third of driest years (2012, 2013). We found the cover crop treatment to have significantly higher soil water storage from 2012-2014 when compared to the no cover crop treatment and in most years greater soil water content later in the growing season when a cover crop was present. We further found that the winter rye cover crop significantly increased the field capacity water content and plant available water compared to the no cover crop treatment. Finally, in 2012 and 2013, we measured maize and soybean biomass every 2-3 weeks and did not see treatment differences in crop growth, leaf area or nitrogen uptake. Final crop yields were not statistically different between the cover and no cover crop treatment in any of the years of this analysis. This research indicates that the long-term use of a winter rye cover crop can improve soil water dynamics without sacrificing cash crop growth.

Soil amendments effects on radiocesium translocation in forest soils.

Science.gov (United States)

Sugiura, Yuki; Ozawa, Hajime; Umemura, Mitsutoshi; Takenaka, Chisato

2016-12-01

We conducted an experiment to investigate the potential of phytoremediation by soil amendments in a forest area. To desorb radiocesium ( 137 Cs) from variable charges in the soil, ammonium sulfate (NH 4 + ) and elemental sulfur (S) (which decrease soil pH) were applied to forest soil collected from contaminated area at a rate of 40 and 80 g/m 2 , respectively. A control condition with no soil treatment was also considered. We defined four groups of aboveground conditions: planted with Quercus serrata, planted with Houttuynia cordata, covered with rice straw as litter, and unplanted/uncovered (control). Cultivation was performed in a greenhouse with a regular water supply for four months. Following elemental sulfur treatment, soil pH values were significantly lower than pH values following ammonium sulfate treatment and no treatment. During cultivation, several plant species germinated from natural seeds. No clear differences in aboveground tissue 137 Cs concentrations in planted Q. serrata and H. cordata were observed among the treatments. However, aboveground tissue 137 Cs concentration values in the germinated plants following elemental sulfur treatment were higher than the values following the ammonium sulfate treatment and no treatment. Although biomass values for Q. serrata, H. cordata, and germinated plants following elemental sulfur treatment tended to be low, the total 137 Cs activities in the aboveground tissue of germinated plants were higher than those following ammonium sulfate treatment and no treatment in rice straw and unplanted conditions. Although no significant differences were observed, 137 Cs concentrations in rice straw following ammonium sulfate and elemental sulfur treatments tended to be higher than those in the control case. The results of this study indicate that elemental sulfur lowers the soil pH for a relatively long period and facilitates 137 Cs translocation to newly emerged and settled plants or litter, but affects plant growth in

The Application of Soil-Agroclimatic Index for Assessing the Agronomic Potential of Arable Lands in the Forest-Steppe Zone of Russia

Science.gov (United States)

Bulgakov, D. S.; Rukhovich, D. I.; Shishkonakova, E. A.; Vil'chevskaya, E. V.

2018-04-01

An assessment of the agronomic potential of arable lands in the forest-steppe zone of Russia (by the example of separate soil-agronomic districts) on the basis of the soil-agroclimatic index developed under the supervision of I.I. Karmanov is considered. The agricultural areas (64) separated on the territory of Russia and characterizing soil-agroclimatic conditions for cultivation of major and accompanying crops are differentiated into soil-agronomic districts (SADs) with due account for the administrative division of the country. A large diversity of agroclimatic and agronomical conditions creates the prerequisites for the inclusion of administrative regions into different SADs. The SADs concept implies a detailed analysis of information on the soil properties, geomorphic conditions, and farming conditions. The agronomic potential for major crops in the key SADs in the forest-steppe zone of the East European Plain (Voronezh and Penza oblasts) is high, though it is 25-30% lower than that in the North Caucasus (for winter wheat, sugar beet, sunflower, and spring barley) and in Kaliningrad oblast (for oats). In Western Siberia (Tyumen, Omsk, and Novosibirsk oblasts) and Eastern Siberia (Krasnoyarsk region and Irkutsk oblast), the agronomic potential of spring crops (wheat, barley, and oats) is only utilized by 35-45% in comparison with their European analogues. In the Far East with its monsoon climate and soil conditions (meadow podbels, brown forest soils), the crops characteristic of the European forest-steppe (soybean, rice, sugar beet) and the Trans-Ural forest-steppe (spring wheat) are cultivated. Their biological potential is utilized by only 50-60% in comparison with the European analogues. The materials of this study give us information on the degree of correspondence between the soilagroclimatic potential of the territory and the biological potential of cultivated crops. This is important in the context of improving the natural-agricultural zoning of Russia

Forest management type influences diversity and community composition of soil fungi across temperate forest ecosystems

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Kezia eGoldmann

2015-11-01

Full Text Available Fungal communities have been shown to be highly sensitive towards shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L., with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L. or spruce (Picea abies Karst. which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure.We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal OTU richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera.This study extends our knowledge

Forest Management Type Influences Diversity and Community Composition of Soil Fungi across Temperate Forest Ecosystems.

Science.gov (United States)

Goldmann, Kezia; Schöning, Ingo; Buscot, François; Wubet, Tesfaye

2015-01-01

Fungal communities have been shown to be highly sensitive toward shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L.), with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L.) or spruce (Picea abies Karst.) which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure. We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal operational taxonomic units richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM) and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera. This study extends our

Molecular characterization of soil bacterial community in a perhumid, low mountain forest.

Science.gov (United States)

Lin, Yu-Te; Whitman, William B; Coleman, David C; Chih-Yu, Chiu

2011-01-01

Forest disturbance often results in changes in soil properties and microbial communities. In the present study, we characterized a soil bacterial community subjected to disturbance using 16S rRNA gene clone libraries. The community was from a disturbed broad-leaved, low mountain forest ecosystem at Huoshaoliao (HSL) located in northern Taiwan. This locality receives more than 4,000 mm annual precipitation, one of the highest precipitations in Taiwan. Based on the Shannon diversity index, Chao1 estimator, richness and rarefaction curve analysis, the bacterial community in HSL forest soils was more diverse than those previously investigated in natural and disturbed forest soils with colder or less humid weather conditions. Analysis of molecular variance also revealed that the bacterial community in disturbed soils significantly differed from natural forest soils. Most of the abundant operational taxonomic units (OTUs) in the disturbed soil community at HSL were less abundant or absent in other soils. The disturbances influenced the composition of bacterial communities in natural and disturbed forests and increased the diversity of the disturbed forest soil community. Furthermore, the warmer and humid weather conditions could also increase community diversity in HSL soils.

Production and reduction of nitrous oxide in agricultural and forest soils.

Science.gov (United States)

Yu, K; Chen, G; Struwe, S; Kjøller, A

2000-06-01

A soil-water slurry experiment was conducted to study the potentials of N2O production and reduction in denitrification of agricultural and beech forest soils in Denmark. The effects of nitrate and ammonium additions on denitrification were also investigated. The forest soil showed a higher denitrification potential than the agricultural soil. However, N2O reduction potential of the agricultural soil was higher than the beech forest soil, shown by the ratio of N2O/N2 approximately 0.11 and 3.65 in the agricultural and the beech forest soils, respectively. Both nitrate and ammonium additions stimulated the N2O production in the two soils, but reduced the N2O reduction rates in the agricultural soil slurries. In contrast to the effect on the agricultural soil, nitrate reduced the N2O reduction rate in the beech forest soil, while ammonium showed a stimulating effect on the N2O reduction activity. After one week incubation, all of the N2O produced was reduced to N2 in the agricultural soil when nitrate was still present. Nitrous oxide reduction in the beech forest soil occurred only when nitrate almost disappeared. The different nitrate inhibitory effect on the N2O reduction activity in the two soils was due to the difference in soil pH. Inhibition of nitrate on N2O reduction was significant under acidic condition. Consequently, soil could serve as a sink of atmospheric N2O under the conditions of anaerobic, pH near neutral and low nitrate content.

Long-Term Soil Chemistry Changes in Aggrading Forest Ecosystems

Science.gov (United States)

Jennifer D. Knoepp; Wayne T. Swank

1994-01-01

Assessing potential long-term forest productivity requires identification of the processes regulating chemical changes in forest soils. We resampled the litter layer and upper two mineral soil horizons, A and AB/BA, in two aggrading southern Appalachian watersheds 20 yr after an earlier sampling. Soils from a mixed-hardwood watershed exhibited a small but significant...

Biological soil crusts are the main contributor to winter soil respiration in a temperate desert ecosystem of China

Science.gov (United States)

He, M. Z.

2012-04-01

Aims Biological soil crusts (BSCs) are a key biotic component of desert ecosystems worldwide. However, most studies carried out to date on carbon (fluxes) in these ecosystems, such as soil respiration (RS), have neglected them. Also, winter RS is reported to be a significant component of annual carbon budget in other ecosystems, however, we have less knowledge about winter RS of BSCs in winter and its contribution to carbon cycle in desert regions. Therefore, the specific objectives of this study were to: (i) quantify the effects of different BSCs types (moss crust, algae crust, physical crust) on the winter RS; (ii) explore relationships of RS against soil temperature and water content for different BSCs, and (iii) assess the relative contribution of BSCs to the annual amount of C released by RS at desert ecosystem level. Methods Site Description The study sites are located at the southeast fringe of the Tengger Desert in the Shapotou region of the Ningxia Hui Autonomous Region [37°32'N and 105°02'E, at 1340 m above mean sea level (a.m.s.l.)], western China. The mean daily temperature in January is -6.9°C , while it is 24.3°C in July. The mean annual precipitation is 186 mm, approximately 80% of which falls between May and September. The annual potential evaporation is 2800 mm. The landscape of the Shapotou region is characterized by large and dense reticulate barchans chains of sand dunes that migrate south-eastward at a velocity of 3-6 m per year. The soil is loose, infertile and mobile and can thus be classified as orthic sierozem and Aeolian sandy soil. Additionally, the soil has a consistent gravimetric water content that ranges from 3 to 4%. The groundwater in the study area is too deep (>60 m) to support large areas of the native vegetation cover; therefore, precipitation is usually the only source of freshwater. The predominant native plants are Hedysarum scoparium Fisch. and Agriophyllum squarrosum Moq., Psammochloa cillosa Bor, which scattered

Contrasting Seasonal Survivorship of Two Migratory Songbirds Wintering in Threatened Mangrove Forests

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Anna M. Calvert

2010-06-01

Full Text Available Long-distance migrants wintering in tropical regions face a number of critical conservation threats throughout their lives, but seasonal estimates of key demographic parameters such as winter survival are rare. Using mist-netting-based mark-recapture data collected in coastal Costa Rica over a six-year period, we examined variation in within- and between-winter survivorship of the Prothonotary Warbler (Protonotaria citrea; 753 young and 376 adults banded, a declining neotropical habitat specialist that depends on threatened mangrove forests during the nonbreeding season. We derived parallel seasonal survivorship estimates for the Northern Waterthrush (Seiurus noveboracensis; 564 young and 93 adults banded, a cohabitant mangrove specialist that has not shown the same population decline in North America, to assess whether contrasting survivorship might contribute to the observed differences in the species’ population trajectories. Although average annual survival probability was relatively similar between the two species for both young and adult birds, monthly estimates indicated that relative to Northern Waterthrush, Prothonotary Warblers exhibited: greater interannual variation in survivorship, especially within winters; greater variation in survivorship among the three study sites; lower average between-winter survivorship, particularly among females, and; a sharp decline in between-winter survivorship from 2003 to 2009 for both age groups and both sexes. Rather than identifying one seasonal vital rate as a causal factor of Prothonotary Warbler population declines, our species comparison suggests that the combination of variable within-winter survival with decreasing between-winter survival demands a multi-seasonal approach to the conservation of this and other tropical-wintering migrants.

Weed infestation of crops in different soils in the protective zone of Roztocze National Park. Part I. Winter and spring cereals

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Marta Ziemińska-Smyk

2013-12-01

Full Text Available The study on weed infestation of crops in different soils in the protective zone of RPN was conducted in the years 1991-1995. The characterization of weed infestation of winter and spring cereals was based on 306 phytosociological records. made with the use of Braun-Blanquet method. The degree of weed infestation in the fields in the protective zone of RPN depended on environment conditions. Both winter and spring cereals in majority of soils were most infested by: Cenaturea cyanus, Apera spica-venti and Vicia hirsta. In the lightest podsolic soils, made of loose sand and slightly loamy sand. winter and spring cereals were additionally infested by Equisetum arvense and two acidophylic species: Seleranthus annuus and Spergula arvensis. The crops in brown loess soil were infested by Matricaria maritima subsp. inodora. The most difficult weed species in brown soil formed from gaizes and limestone soil were: Convolvulus arvensis, Papaver rhoeas and Galium aparine. Moreover winter cercals in limestone soil showed high or medium infestation with Consolida regalis, Aethusa cynapium, Lathyrus tuberosus and low infestation with Apera spica-venti and Centaurea cyanus. Spring cereals were less infested than winter cereals. Apera spica-venti and Centaurea cyanus were less common with spring cereals than with winter cereals. Also, spring cereals showed high or medium infestation with Convolvulus arvensis. Spring cereals in some soil units were infested by Chenopodium album and Stellaria media. There was also higher infestation of spring cereals in limestone soils with Avena fatua, Veronica persica, Sinapis arvensis and Sonchus arvensis, compared to winter cereals in limestone soils.

Transforming Pinus pinaster forest to recreation site: preliminary effects on LAI, some forest floor, and soil properties.

Science.gov (United States)

Öztürk, Melih; Bolat, İlyas

2014-04-01

This study investigates the effects of forest transformation into recreation site. A fragment of a Pinus pinaster plantation forest was transferred to a recreation site in the city of Bartın located close to the Black Sea coast of northwestern Turkey. During the transformation, some of the trees were selectively removed from the forest to generate more open spaces for the recreationists. As a result, Leaf Area Index (LAI) decreased by 0.20 (about 11%). Additionally, roads and pathways were introduced into the site together with some recreational equipment sealing parts of the soil surface. Consequently, forest environment was altered with a semi-natural landscape within the recreation site. The purpose of this study is to assess the effects of forest transformation into recreation site particularly in terms of the LAI parameter, forest floor, and soil properties. Preliminary monitoring results indicate that forest floor biomass is reduced by 26% in the recreation site compared to the control site. Soil temperature is increased by 15% in the recreation site where selective removal of trees expanded the gaps allowing more light transmission. On the other hand, the soil bulk density which is an indicator of soil compaction is unexpectedly slightly lower in the recreation site. Organic carbon (C(org)) and total nitrogen (N(total)) together with the other physical and chemical parameter values indicate that forest floor and soil have not been exposed to much disturbance. However, subsequent removal of trees that would threaten the vegetation, forest floor, and soil should not be allowed. The activities of the recreationists are to be concentrated on the paved spaces rather than soil surfaces. Furthermore, long-term monitoring and management is necessary for both the observation and conservation of the site.

Effects of exotic plantation forests on soil edaphon and organic matter fractions.

Science.gov (United States)

Xu, Gang; Liu, Yao; Long, Zhijian; Hu, Shanglian; Zhang, Yuanbin; Jiang, Hao

2018-06-01

There is uncertainty and limited knowledge regarding soil microbial properties and organic matter fractions of natural secondary forest accompanying chemical environmental changes of replacement by pure alien plantation forests in a hilly area of southwest of Sichuan province China. The aim of this study was to evaluate the impact of natural secondary forest (NSF) to pure Cryptomeria fortunei forest (CFF) and Cunninghamia lanceolata forest (CLF) on soil organic fractions and microbial communities. The results showed that the soil total phospholipid fatty acids (PLFAs), total bacteria and fungi, microbial carbon pool, organic recalcitrant carbon (C) and (N) fractions, soil microbial quotient and labile and recalcitrant C use efficiencies in each pure plantation were significantly decreased, but their microbial N pool, labile C and N pools, soil carbon dioxide efflux, soil respiratory quotient and recalcitrant N use efficiency were increased. An RDA analysis revealed that soil total PLFAs, total bacteria and fungi and total Gram-positive and Gram-negative bacteria were significantly associated with exchangeable Al 3+ , exchangeable acid, Al 3+ , available P and Mg 2+ and pH, which resulted into microbial functional changes of soil labile and recalcitrant substrate use efficiencies. Modified microbial C- and N-use efficiency due to forest conversion ultimately meets those of rapidly growing trees in plantation forests. Enlarged soil labile fractions and soil respiratory quotients in plantation forests would be a potential positive effect for C source in the future forest management. Altogether, pure plantation practices could provoke regulatory networks and functions of soil microbes and enzyme activities, consequently leading to differentiated utilization of soil organic matter fractions accompanying the change in environmental factors. Copyright © 2018 Elsevier B.V. All rights reserved.

Litter input controls on soil carbon in a temperate deciduous forest

DEFF Research Database (Denmark)

Bowden, Richard D.; Deem, Lauren; Plante, Alain F.

2014-01-01

Above- and belowground litter inputs in a temperate deciduous forest were altered for 20 yr to determine the importance of leaves and roots on soil C and soil organic matter (SOM) quantity and quality. Carbon and SOM quantity and quality were measured in the O horizon and mineral soil to 50 cm...... soil C, but decreases in litter inputs resulted in rapid soil C declines. Root litter may ultimately provide more stable sources of soil C. Management activities or environmental alterations that decrease litter inputs in mature forests can lower soil C content; however, increases in forest...

[Response of forest bird communities to forest gap in winter in southwestern China].

Science.gov (United States)

Zhao, Dong-Dong; Wu, Ying-Huan; Lu, Zhou; Jiang, Guang-Wei; Zhou, Fang

2013-06-01

Although forest gap ecology is an important field of study, research remains limited. By plot setting and point counted observation, the response of birds to forest gaps in winter as well as bird distribution patterns in forest gaps and intact canopies were studied in a north tropical monsoon forest of southwestern China from November 2011 to February 2012 in the Fangcheng Golden Camellia National Nature Reserve, Guangxi. The regression equation of bird species diversity to habitat factor was Y1=0.611+0.002 X13+0.043 X2+0.002 X5-0.003 X8+0.006 X10+0.008 X1 and the regression equation of bird species dominance index to habitat factor was Y3=0.533+0.001 X13+0.019 X2+0.002 X3-0.017 X4+0.002 X1. There were 45 bird species (2 orders and 13 families) recorded in the forest gap, accounting for 84.9% of all birds (n=45), with an average of 9.6 species (range: 2-22). Thirty-nine bird species (5 orders and 14 families) were recorded in non-gap areas, accounting for 73.6% of all birds (n=39), with an average of 5.3 species (range: 1-12). These results suggested that gap size, arbor average height (10 m from gap margin), arbor quantity (10 m from gap margin), shrub quantity (10 m from gap margin), herbal average coverage (1 m from gap margin) and bare land ratio were the key forest gap factors that influenced bird diversities. On the whole, bird diversity in the forest gap was greater than in the intact canopy. Spatial distributions in the forest gaps were also observed in the bird community. Most birds foraged in the "middle" and "canopy" layers in the vertical stratification. In addition, "nearly from" and "close from" contained more birds in relation to horizontal stratification. Feeding niche differentiation was suggested as the main reason for these distribution patterns.

Arbuscular mycorrhizal propagules in soils from a tropical forest and an abandoned cornfield in Quintana Roo, Mexico: visual comparison of most-probable-number estimates.

Science.gov (United States)

Ramos-Zapata, José A; Guadarrama, Patricia; Navarro-Alberto, Jorge; Orellana, Roger

2011-02-01

The present study was aimed at comparing the number of arbuscular mycorrhizal fungi (AMF) propagules found in soil from a mature tropical forest and that found in an abandoned cornfield in Noh-Bec Quintana Roo, Mexico, during three seasons. Agricultural practices can dramatically reduce the availability and viability of AMF propagules, and in this way delay the regeneration of tropical forests in abandoned agricultural areas. In addition, rainfall seasonality, which characterizes deciduous tropical forests, may strongly influence AMF propagules density. To compare AMF propagule numbers between sites and seasons (summer rainy, winter rainy and dry season), a "most probable number" (MPN) bioassay was conducted under greenhouse conditions employing Sorgum vulgare L. as host plant. Results showed an average value of 3.5 ± 0.41 propagules in 50 ml of soil for the mature forest while the abandoned cornfield had 15.4 ± 5.03 propagules in 50 ml of soil. Likelihood analysis showed no statistical differences in MPN of propagules between seasons within each site, or between sites, except for the summer rainy season for which soil from the abandoned cornfield had eight times as many propagules compared to soil from the mature forest site for this season. Propagules of arbuscular mycorrhizal fungi remained viable throughout the sampling seasons at both sites. Abandoned areas resulting from traditional slash and burn agriculture practices involving maize did not show a lower number of AMF propagules, which should allow the establishment of mycotrophic plants thus maintaining the AMF inoculum potential in these soils.

Human impacts on soil carbon dynamics of deep-rooted Amazonian forests

Science.gov (United States)

Nepstad, Daniel C.; Stone, Thomas A.; Davidson, Eric A.

1994-01-01

Deforestation and logging degrade more forest in eastern and southern Amazonia than in any other region of the world. This forest alteration affects regional hydrology and the global carbon cycle, but our current understanding of these effects is limited by incomplete knowledge of tropical forest ecosystems. It is widely agreed that roots are concentrated near the soil surface in moist tropical forests, but this generalization incorrectly implies that deep roots are unimportant in water and C budgets. Our results indicate that half of the closed-canopy forests of Brazilian Amazonic occur where rainfall is highly seasonal, and these forests rely on deeply penetrating roots to extract soil water. Pasture vegetation extracts less water from deep soil than the forest it replaces, thus increasing rates of drainage and decreasing rates of evapotranspiration. Deep roots are also a source of modern carbon deep in the soil. The soils of the eastern Amazon contain more carbon below 1 m depth than is present in above-ground biomass. As much as 25 percent of this deep soil C could have annual to decadal turnover times and may be lost to the atmosphere following deforestation. We compared the importance of deep roots in a mature, evergreen forest with an adjacent man-made pasture, the most common type of vegetation on deforested land in Amazonia. The study site is near the town of Paragominas, in the Brazilian state of Para, with a seasonal rainfall pattern and deeply-weathered, kaolinitic soils that are typical for large portions of Amazonia. Root distribution, soil water extraction, and soil carbon dynamics were studied using deep auger holes and shafts in each ecosystem, and the phenology and water status of the leaf canopies were measured. We estimated the geographical distribution of deeply-rooting forests using satellite imagery, rainfall data, and field measurements.

Modeling soil erosion and transport on forest landscape

Science.gov (United States)

Ge Sun; Steven G McNulty

1998-01-01

Century-long studies on the impacts of forest management in North America suggest sediment can cause major reduction on stream water quality. Soil erosion patterns in forest watersheds are patchy and heterogeneous. Therefore, patterns of soil erosion are difficult to model and predict. The objective of this study is to develop a user friendly management tool for land...

Factors of influencing dissolved organic carbon stabilization in two cambic forest soils with contrasting soil-forming processes

Science.gov (United States)

Kawasaki, M.; Ohte, N.; Asano, Y.; Uchida, T.; Kabeya, N.; Kim, S.

2004-05-01

Stabilization of Dissolved Organic Carbon (DOC) in forest soil is a major process of soil organic carbon formation. However, the factors influencing DOC stabilization are poorly understood. To clarify the factors that affect the stabilization of DOC in forest soil mantle, we measured DOC concentrations and soil properties which were DOC adsorption efficiency at two adjacent cambic forest soils with contrasting forest management histories in Tanakami Mountains, central Japan. Matsuzawa was devastated about 1,200 years ago by excessive timber use and remained denuded for a long period. Hillside restoration and reforestation work have been carried out over the last 100 years and soil loss has been reduced. Fudoji is covered with undisturbed forest (mixed stands of cypress and oaks) with developed forest soils (more than 2,600 years old). There was no apparent seasonal variation in DOC concentration in the soil solution in either catchment. In addition, there were no significant relationships between the DOC concentration, soil temperature, and new water ratio. These results indicate that temporal variation in biological activity and rainfall-runoff process have little effect on temporal variation in DOC. The vertical variation in the DOC adsorption efficiency and DOC concentration differed between Matsuzawa and Fudoji, and the highest DOC removal rate occurred at the lowest DOC adsorption efficiency in the 0 to 10-cm soil layer at Fudoji. These results suggest that DOC removal rate is independent of DOC adsorption efficiency. Below 60 cm soil depth, DOC fluxes were constant and dissolved organic Al concentrations were little or zero in either catchment. These results suggest that abiotic precipitation of DOC is a major mechanism for stabilization of DOC. Therefore, DOC content which is able to form metal complexes may be the most important factor of influencing DOC stabilization in cambic forest soil.

CO2 deficit in temperate forest soils receiving high atmospheric N-deposition.

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Fleischer, Siegfried

2003-02-01

Evidence is provided for an internal CO2 sink in forest soils, that may have a potential impact on the global CO2-budget. Lowered CO2 fraction in the soil atmosphere, and thus lowered CO2 release to the aboveground atmosphere, is indicated in high N-deposition areas. Also at forest edges, especially of spruce forest, where additional N-deposition has occurred, the soil CO2 is lowered, and the gradient increases into the closed forest. Over the last three decades the capacity of the forest soil to maintain the internal sink process has been limited to a cumulative supply of approximately 1000 and 1500 kg N ha(-1). Beyond this limit the internal soil CO2 sink becomes an additional CO2 source, together with nitrogen leaching. This stage of "nitrogen saturation" is still uncommon in closed forests in southern Scandinavia, however, it occurs in exposed forest edges which receive high atmospheric N-deposition. The soil CO2 gradient, which originally increases from the edge towards the closed forest, becomes reversed.

Sources of nitrous oxide emitted from European forest soils

Directory of Open Access Journals (Sweden)

P. Ambus

2006-01-01

Full Text Available Forest ecosystems may provide strong sources of nitrous oxide (N2O, which is important for atmospheric chemical and radiative properties. Nonetheless, our understanding of controls on forest N2O emissions is insufficient to narrow current flux estimates, which still are associated with great uncertainties. In this study, we have investigated the quantitative and qualitative relationships between N-cycling and N2O production in European forests in order to evaluate the importance of nitrification and denitrification for N2O production. Soil samples were collected in 11 different sites characterized by variable climatic regimes and forest types. Soil N-cycling and associated production of N2O was assessed following application of 15N-labeled nitrogen. The N2O emission varied significantly among the different forest soils, and was inversely correlated to the soil C:N ratio. The N2O emissions were significantly higher from the deciduous soils (13 ng N2O-N cm-3 d-1 than from the coniferous soils (4 ng N2O-N cm-3 d-1. Nitrate (NO3- was the dominant substrate for N2O with an average contribution of 62% and exceeding 50% at least once for all sites. The average contribution of ammonium (NH4+ to N2O averaged 34%. The N2O emissions were correlated with gross nitrification activities, and as for N2O, gross nitrification was also higher in deciduous soils (3.4 µg N cm-3 d-1 than in coniferous soils (1.1 µg N cm-3 d-1. The ratio between N2O production and gross nitrification averaged 0.67% (deciduous and 0.44% (coniferous. Our study suggests that changes in forest composition in response to land use activities and global change may have implications for regional budgets of greenhouse gases. From the study it also became clear that N2O emissions were driven by the nitrification activity, although the N2O was produced per se mainly from denitrification. Increased nitrification in response to accelerated N inputs predicted for forest ecosystems in Europe may

Indicators of soil quality in the implantation of no-till system with winter crops

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Marco Antonio Nogueira

Full Text Available We assessed the effect of different winter crops on indicators of soil quality related to C and N cycling and C fractions in a Rhodic Kandiudult under no-till system at implantation, during two growing seasons, in Londrina PR Brazil. The experimental design was randomized blocks with split-plot in time arrangement, with four replications. The parcels were the winter crops: multicropping of cover crops with black oat (Avena strigosa, hairy vetch (Vicia villosa and fodder radish (Raphanus sativus; sunflower (Heliantus annuus intercropped with Urochloa ruziziensis; corn (Zea mays intercropped with Urochloa; and corn; fodder radish; or wheat (Triticum aestivum as sole crops. The subplots were the years: 2008 and 2009. Determinations consisted of total organic C, labile and resistant C, total N, microbial biomass C and N, the C/N ratio of soil organic matter, and the microbial quotient (qMic, besides microbiological and biochemical attributes, assessed only in 2009. The attributes significantly changed with the winter crops, especially the multicropping of cover crops and fodder radish, as well as effect of years. Despite stimulating the microbiological/biochemical activity, fodder radish cropping decreased the soil C in the second year, likewise the wheat cropping. The multicropping of cover crops in winter is an option for management in the establishment of no-till system, which contributes to increase the concentrations of C and stimulate the soil microbiological/biochemical activity.

Complementary models of tree species-soil relationships in old-growth temperate forests

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Cross, Alison; Perakis, Steven S.

2011-01-01

Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and species specific studies of tree species soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common tree species across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess tree species soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative species based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. Tree species soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by tree species across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among species in both forest floor and mineral soil, and most of ten followed adivergence model,where by species differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent species differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent species differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and

Energy balance of a sparse coniferous high-latitude forest under winter conditions

DEFF Research Database (Denmark)

Gryning, Sven-Erik; Batchvarova, E.; Bruin, H.A.R. de

2001-01-01

was simulated for a three month period. For conditions with a cloud cover of less than 7 oktas good agreement between model predictions and measurements were found. For cloud cover 7 and 8 oktas a considerable spread can be observed. To apply the proposed energy balance model, the global radiation must......Measurements carried out in Northern Finland on radiation and turbulent fluxes over a sparse, sub-arctic boreal forest with snow covered ground were analysed. The measurements represent late winter conditions characterised by low solar elevation angles. During the experiment (12-24 March 1997) day...... and night were about equally long. At low solar elevation angles the forest shades most of the snow surface. Therefore an important part of the radiation never reaches the snow surface but is absorbed by the forest. The sensible heat flux above the forest was fairly large, reaching more than 100 W m(-2...

Effects of Forest Gaps on Litter Lignin and Cellulose Dynamics Vary Seasonally in an Alpine Forest

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Han Li

2016-01-01

Full Text Available To understand how forest gaps and the associated canopy control litter lignin and cellulose dynamics by redistributing the winter snow coverage and hydrothermal conditions in the growing season, a field litterbag trial was conducted in the alpine Minjiang fir (Abies faxoniana Rehder and E.H. Wilson forest in a transitional area located in the upper reaches of the Yangtze River and the eastern Tibetan Plateau. Over the first year of litter decomposition, the litter exhibited absolute cellulose loss and absolute lignin accumulation except for the red birch litter. The changes in litter cellulose and lignin were significantly affected by the interactions among gap position, period and species. Litter cellulose exhibited a greater loss in the winter with the highest daily loss rate observed during the snow cover period. Both cellulose and lignin exhibited greater changes under the deep snow cover at the gap center in the winter, but the opposite pattern occurred under the closed canopy in the growing season. The results suggest that decreased snowpack seasonality due to winter warming may limit litter cellulose and lignin degradation in alpine forest ecosystems, which could further inhibit litter decomposition. As a result, the ongoing winter warming and gap vanishing would slow soil carbon sequestration from foliar litter in cold biomes.

Soil Respiration of Three Mangrove Forests on Sanibel Island, Florida

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Cartwright, F.; Bovard, B. D.

2011-12-01

Carbon cycling studies conducted in mangrove forests have typically focused on aboveground processes. Our understanding of carbon storage in these systems is therefore limited by the lack information on belowground processes such as fine root production and soil respiration. To our knowledge there exist no studies investigating temporal patterns in and environmental controls on soil respiration in multiple types of mangrove ecosystems concurrently. This study is part of a larger study on carbon storage in three mangrove forests on Sanibel Island, Florida. Here we report on eight months of soil respiration data within these forests that will ultimately be incorporated into an annual carbon budget for each habitat type. Soil respiration was monitored in the following three mangrove habitat types: a fringe mangrove forest dominated by Rhizophora mangle, a basin mangrove forest dominated by Avicennia germinans, and a higher elevation forest comprised of a mix of Avicennia germinans and Laguncularia racemosa, and non-woody salt marsh species. Beginning in June of 2010, we measured soil emissions of carbon dioxide at 5 random locations within three-100 m2 plots within each habitat type. Sampling was performed at monthly intervals and conducted over the course of three days. For each day, one plot from each habitat type was measured. In addition to soil respiration, soil temperature, salinity and gravimetric moisture content were also measured. Our data indicate the Black mangrove forest, dominated by Avicennia germinans, experiences the highest rates of soil respiration with a mean rate of 4.61 ± 0.60 μmol CO2 m-2 s-1. The mixed mangrove and salt marsh habitat has the lowest soil carbon emission rates with a mean of 2.78 ± 0.40 μmol CO2 m-2 s-1. Soil carbon effluxes appear to peak in the early part of the wet season around May to June and are lower and relatively constant the remainder of the year. Our data also suggest there are important but brief periods where

[Effects of climate change on forest soil organic carbon storage: a review].

Science.gov (United States)

Zhou, Xiao-yu; Zhang, Cheng-yi; Guo, Guang-fen

2010-07-01

Forest soil organic carbon is an important component of global carbon cycle, and the changes of its accumulation and decomposition directly affect terrestrial ecosystem carbon storage and global carbon balance. Climate change would affect the photosynthesis of forest vegetation and the decomposition and transformation of forest soil organic carbon, and further, affect the storage and dynamics of organic carbon in forest soils. Temperature, precipitation, atmospheric CO2 concentration, and other climatic factors all have important influences on the forest soil organic carbon storage. Understanding the effects of climate change on this storage is helpful to the scientific management of forest carbon sink, and to the feasible options for climate change mitigation. This paper summarized the research progress about the distribution of organic carbon storage in forest soils, and the effects of elevated temperature, precipitation change, and elevated atmospheric CO2 concentration on this storage, with the further research subjects discussed.

The variations of aluminium species in mountainous forest soils and its implications to soil acidification.

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Bradová, Monika; Tejnecký, Václav; Borůvka, Luboš; Němeček, Karel; Ash, Christopher; Šebek, Ondřej; Svoboda, Miroslav; Zenáhlíková, Jitka; Drábek, Ondřej

2015-11-01

Aluminium (Al) speciation is a characteristic that can be used as a tool for describing the soil acidification process. The question that was answered is how tree species (beech vs spruce) and type of soil horizon affect Al speciation. Our hypotesis is that spruce and beech forest vegetation are able to modify the chemical characteristics of organic horizon, hence the content of Al species. Moreover, these characteristics are seasonally dependent. To answer these questions, a detailed chromatographic speciation of Al in forest soils under contrasting tree species was performed. The Jizera Mountains area (Czech Republic) was chosen as a representative mountainous soil ecosystem. A basic forestry survey was performed on the investigated area. Soil and precipitation samples (throughfall, stemflow) were collected under both beech and spruce stands at monthly intervals from April to November during the years 2008-2011. Total aluminium content and Al speciation, pH, and dissolved organic carbon were determined in aqueous soil extracts and in precipitation samples. We found that the most important factors affecting the chemistry of soils, hence content of the Al species, are soil horizons and vegetation cover. pH strongly affects the amount of Al species under both forests. Fermentation (F) and humified (H) organic horizons contain a higher content of water extractable Al and Al(3+) compared to organo-mineral (A) and mineral horizons (B). With increasing soil profile depth, the amount of water extractable Al, Al(3+) and moisture decreases. The prevailing water-extractable species of Al in all studied soils and profiles under both spruce and beech forests were organically bound monovalent Al species. Distinct seasonal variations in organic and mineral soil horizons were found under both spruce and beech forests. Maximum concentrations of water-extractable Al and Al(3+) were determined in the summer, and the lowest in spring.

The microbiology of forest soils: a literature review

Energy Technology Data Exchange (ETDEWEB)

Hendrickson, O; Robinson, J B

1982-01-01

This report discusses the activities of two major groups of forest soil microorganisms, the bacteria and the fungi. Special attention is paid to their participation in the decay of major forest litter substrates, including leaves, branches and roots. The influence of bacteria and fungi in symbiotic associations with woody plant roots upon the cycles of carbon and nitrogen is described. The impacts of certain forest mamagement alternatives are assessed in terms of the creation of elimination of suitable environments for the activity of soil microorganisms. A bibliography is included. 507 refs., 1 tab.

Nitrogen Deposition Effects on Soil Carbon Dynamics in Temperate Forests

DEFF Research Database (Denmark)

Ginzburg Ozeri, Shimon

Soils contain the largest fraction of terrestrial carbon (C). Understanding the factors regulating the decomposition and storage of soil organic matter (SOM) is essential for predictions of the C sink strength of the terrestrial environment in the light of global change. Elevated long-term nitrog...... implications for modelling the carbon sink-strength of temperate forests under global change.......Soils contain the largest fraction of terrestrial carbon (C). Understanding the factors regulating the decomposition and storage of soil organic matter (SOM) is essential for predictions of the C sink strength of the terrestrial environment in the light of global change. Elevated long-term nitrogen...... (N) deposition into forest ecosystems has been increasing globally and was hypothesized to raise soil organic C (SOC) stocks by increasing forest productivity and by reducing SOM decomposition. Yet, these effects of N deposition on forest SOC stocks are uncertain and largely based on observations...

Using synthetic polymers to reduce soil erosion after forest fires in Mediterranean soils

Science.gov (United States)

Lado, Marcos; Ben-Hur, Meni; Inbar, Assaf

2010-05-01

Forest fires are a major environmental problem in the Mediterranean region because they result in a loss of vegetation cover, changes in biodiversity, increases in greenhouse gasses emission and a potential increase of runoff and soil erosion. The large increases in runoff and sediment yields after high severity fires have been attributed to several factors, among them: increase in soil water repellency; soil sealing by detached particles and by ash particles, and the loss of a surface cover. The presence of a surface cover increases infiltration, and decreases runoff and erosion by several mechanisms which include: rainfall interception, plant evapotranspiration, preservation of soil structure by increasing soil organic matter, and increasing surface roughness. The loss of vegetation cover as a result of fire leaves the surface of the soil exposed to the direct impact of the raindrops, and therefore the sensitivity of the soil to runoff generation and soil loss increases. In this work, we propose a new method to protect soils against post-fire erosion based on the application of synthetic polymers to the soil. Laboratory rainfall simulations and field runoff plots were used to analyze the suitability of the application of synthetic polymers to reduce soil erosion and stabilize soil structure in Mediterranean soils. The combination of these two processes will potentially favor a faster recovery of the vegetation structure. This method has been successfully applied in arable land, however it has not been tested in burnt forests. The outcome of this study may provide important managerial tools for forest management following fires.

Chloride Concentration in the Soil Polluted with Bishophit Used in Winter and its Effect on Herbaceous Plants

Directory of Open Access Journals (Sweden)

Asta Strėlkutė

2014-10-01

Full Text Available For road maintenance in winter, various chemical reagents, considering their physical and chemical properties, are chosen taking into account economic indicators. After a long winter season, large amounts of chemical reagents are used. During the winter season, dusting chlorides, first of all, fall on the roadway and a part of those reach roadsides where directly pollute the soil of the buffer zone and affect vegetation during the growing season. Chloride content in soil reduces the absorption of nutrients, which hinders the development of plants. It also has an effect on the metabolism of soil organisms, and therefore the loss of soil fertility. Due to high chloride content, land becomes unsuitable for plant growth. Studies used different concentrations (9 ml, 12 ml and 46 ml of bishophit. Chloride concentration in soil extract has been determined applying the volumetric method and employing silver nitrate titration. It has been determined that the amount of chloride in the soil contaminated with 9 ml makes 89.21 mg/kg, 12 ml – 94, 25 mg/kg and 164.32 mg/kg.

Life stage influences the resistance and resilience of black mangrove forests to winter climate extremes

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Osland, Michael J.; Day, Richard H.; From, Andrew S.; McCoy, Megan L.; McLeod, Jennie L.; Kelleway, Jeffrey

2015-01-01

In subtropical coastal wetlands on multiple continents, climate change-induced reductions in the frequency and intensity of freezing temperatures are expected to lead to the expansion of woody plants (i.e., mangrove forests) at the expense of tidal grasslands (i.e., salt marshes). Since some ecosystem goods and services would be affected by mangrove range expansion, there is a need to better understand mangrove sensitivity to freezing temperatures as well as the implications of changing winter climate extremes for mangrove-salt marsh interactions. In this study, we investigated the following questions: (1) how does plant life stage (i.e., ontogeny) influence the resistance and resilience of black mangrove (Avicennia germinans) forests to freezing temperatures; and (2) how might differential life stage responses to freeze events affect the rate of mangrove expansion and salt marsh displacement due to climate change? To address these questions, we quantified freeze damage and recovery for different life stages (seedling, short tree, and tall tree) following extreme winter air temperature events that occurred near the northern range limit of A. germinans in North America. We found that life stage affects black mangrove forest resistance and resilience to winter climate extremes in a nonlinear fashion. Resistance to winter climate extremes was high for tall A. germinans trees and seedlings, but lowest for short trees. Resilience was highest for tall A. germinans trees. These results suggest the presence of positive feedbacks and indicate that climate-change induced decreases in the frequency and intensity of extreme minimum air temperatures could lead to a nonlinear increase in mangrove forest resistance and resilience. This feedback could accelerate future mangrove expansion and salt marsh loss at rates beyond what would be predicted from climate change alone. In general terms, our study highlights the importance of accounting for differential life stage responses and

Effects of annual and interannual environmental variability on soil fungi associated with an old-growth, temperate hardwood forest.

Science.gov (United States)

Burke, David J

2015-06-01

Seasonal and interannual variability in temperature, precipitation and chemical resources may regulate fungal community structure in forests but the effect of such variability is still poorly understood. In this study, I examined changes in fungal communities over two years and how these changes were correlated to natural variation in soil conditions. Soil cores were collected every month for three years from permanent plots established in an old-growth hardwood forest, and molecular methods were used to detect fungal species. Species richness and diversity were not consistent between years with richness and diversity significantly affected by season in one year but significantly affected by depth in the other year. These differences were associated with variation in late winter snow cover. Fungal communities significantly varied by plot location, season and depth and differences were consistent between years but fungal species within the community were not consistent in their seasonality or in their preference for certain soil depths. Some fungal species, however, were found to be consistently correlated with soil chemistry across sampled years. These results suggest that fungal community changes reflect the behavior of the individual species within the community pool and how those species respond to local resource availability. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Methane production potential and microbial community structure for different forest soils

Science.gov (United States)

Matsumoto, Y.; Ueyama, M.; Kominami, Y.; Endo, R.; Tokumoto, H.; Hirano, T.; Takagi, K.; Takahashi, Y.; Iwata, H.; Harazono, Y.

2017-12-01

Forest soils are often considered as a methane (CH4) sink, but anaerobic microsites potentially decrease the sink at the ecosystem scale. In this study, we measured biological CH4 production potential of soils at various ecosystems, including upland forests, a lowland forest, and a bog, and analyzed microbial community structure using 16S ribosomal RNA (rRNA) genes. Three different types of soil samples (upland, bank of the stream, and center of the stream) were collected from Yamashiro forest meteorology research site (YMS) at Kyoto, Japan, on 11 May 2017. The soils were incubated at dark and anaerobic conditions under three different temperatures (37°C, 25°C, and 10°C) from 9 June 2017. The upland soils emitted CH4 with largest yields among the three soils at 37°C and 25°C, although no CH4 emission was observed at 10°C. For all temperature ranges, the emission started to increase with a 14- to 20-days lag after the start of the incubation. The lag indicates a slow transition to anaerobic conditions; as dissolved oxygen in water decreased, the number and/or activity of anaerobic bacteria like methanogens increased. The soils at the bank and center of the stream emitted CH4 with smaller yields than the upland soils in the three temperature ranges. The microbial community analyses indicate that methanogenic archaea presented at the three soils including the aerobic upland soil, but compositions of methanogenic archaea were different among the soils. In upland soils, hydrogenotrophic methanogens, such as Methanobacterium and Methanothermobacter, consisted almost all of the total methanogen detected. In the bank and center of the stream, soils contained approximately 10-25% of acetoclastic methanogens, such as Methanosarcina and Methanosaeta, among the total methanogen detected. Methanotrophs, a genus of Methanobacteriaceae, was appeared in the all types of soils. We will present results from same incubation and 16S rRNA analyses for other ecosystems, including

Contribution of fine tree roots to the silicon cycle in a temperate forest ecosystem developed on three soil types

Science.gov (United States)

Turpault, Marie-Pierre; Calvaruso, Christophe; Kirchen, Gil; Redon, Paul-Olivier; Cochet, Carine

2018-04-01

.5-2.0 times higher in the Si-rich DC compared to the Si-poor RL. In terms of the DSi budget, DSi production was large in the three plots in the forest floor (9.9 to 12.7 kg ha-1 yr-1), as well as in the superficial soil layer (5.3 to 14.5 kg ha-1 yr-1), and decreased with soil depth. An immobilization of DSi was even observed at 90 cm depth in plot DC (-1.7 kg ha-1 yr-1). The amount of Si leached from the soil profile was relatively low compared to the annual uptake by trees (13 % in plot DC to 29 % in plot RL). The monthly measurements demonstrated that the seasonal dynamics of the DSi budget were mainly linked to biological activity. Notably, the peak of dissolved Si production in the superficial soil layer occurred during winter and probably resulted from fine-root decomposition. Our study reveals that biological processes, particularly those involving fine roots, play a predominant role in the Si cycle in temperate forest ecosystems, while the geochemical processes appear to be limited.

Sewage sludge fertiliser use: implications for soil and plant copper evolution in forest and agronomic soils.

Science.gov (United States)

Ferreiro-Domínguez, Nuria; Rigueiro-Rodríguez, Antonio; Mosquera-Losada, M Rosa

2012-05-01

Fertilisation with sewage sludge may lead to crop toxicity and environmental degradation. This study aims to evaluate the effects of two types of soils (forest and agronomic), two types of vegetation (unsown (coming from soil seed bank) and sown), and two types of fertilisation (sludge fertilisation and mineral fertilisation, with a no fertiliser control) in afforested and treeless swards and in sown and unsown forestlands on the total and available Cu concentration in soil, the leaching of this element and the Cu levels in plant. The experimental design was completely randomised with nine treatments and three replicates. Fertilisation with sewage sludge increased the concentration of Cu in soil and plant, but the soil values never exceeded the maximum set by Spanish regulations. Sewage sludge inputs increased both the total and Mehlich 3 Cu concentrations in agronomic soils and the Cu levels in plant developed in agronomic and forest soils, with this effect pronounced in the unsown swards of forest soils. Therefore, the use of high quality sewage sludge as fertiliser may improve the global productivity of forest, agronomic and silvopastoral systems without creating environmental hazards. Copyright © 2012 Elsevier B.V. All rights reserved.

Old-growth forests can accumulate carbon in soils

Science.gov (United States)

Zhou, G.; Liu, S.; Li, Z.; Zhang, Dongxiao; Tang, X.; Zhou, C.; Yan, J.; Mo, J.

2006-01-01

Old-growth forests have traditionally been considered negligible as carbon sinks because carbon uptake has been thought to be balanced by respiration. We show that the top 20-centimeter soil layer in preserved old-growth forests in southern China accumulated atmospheric carbon at an unexpectedly high average rate of 0.61 megagrams of carbon hectare-1 year-1 from 1979 to 2003. This study suggests that the carbon cycle processes in the belowground system of these forests are changing in response to the changing environment. The result directly challenges the prevailing belief in ecosystem ecology regarding carbon budget in old-growth forests and supports the establishment of a new, nonequilibrium conceptual framework to study soil carbon dynamics.

[Microelement contents of litter, soil fauna and soil in Pinus koraiensis and broad-leaved mixed forest].

Science.gov (United States)

Yin, Xiu-qin; Li, Jin-xia; Dong, Wei-hua

2007-02-01

The analysis on the Mn, Zn and Cu contents of litter, soil fauna and soil in Pinus korazenszis and broad-leaved mixed forest in Liangshui Natural Reserve of Xiaoxing' an Mountains showed that the test microelement contents in the litter, soil fauna and soil all followed the sequence of Mn > Zn > Cu, but varied with these environmental components, being in the sequence of soil > litter > soil fauna for Mn, soil fauna > litter and soil for Zn, and soil fauna > soil > litter for Cu. The change range of test microelement contents in litter was larger in broad-leaved forest than in coniferous forest. Different soil fauna differed in their microelement-enrichment capability, e. g. , earthworm, centipede, diplopod had the highest content of Mn, Zn and Cu, respectively. The contents of test microelements in soil fauna had significant correlations with their environmental background values, litter decomposition rate, food habit of soil fauna, and its absorbing selectivity and enrichment to microelements. The microelements contained in 5-20 cm soil layer were more than those in 0-5 cm soil layer, and their dynamics differed in various soil layers.

Soil organic matter status in forest soils - possible indicators for climate change induced site shifts

Science.gov (United States)

Koch, Nadine; Thiele-Bruhn, Sören

2010-05-01

The quantity and quality of soil organic matter (SOM) and SOM pools and thus the soil properties related to carbon sequestration and water retention are not constant but exhibit considerable variation through changing climate. In total changes in soil fertility and an increase in plant stress are expected. This is relevant for northwest Europe as well and may have economic and social impacts since functions of forests for wood production, groundwater recharge, soil protection and recreation might be affected. The study is done by comparative investigation of selected sites at four watersheds that represent typical forest stands in the region of Luxembourg and South West Germany. The aim is to identify SOM storage and stability in forest soils and its dependence on site properties and interaction with tree stand conditions. According to state of the art fractionation schemes functional C pools in forest soils and their stabilization mechanisms are investigated. In particular, distribution patterns are determined depending on location, tree stand and climatic conditions. Aim is to identify characteristics of SOM stability through fractionation of SOM according to density, particle size and chemical extractability and their subsequent analytical characterization. So far, reasons about the origin, composition and stabilization mechanisms underlying the different SOM pools are not fully understood. Presented are different patterns of distribution of SOM in relation to land use and site conditions, as well as similarities and differences between the different forest soils and results in addition to passive OM pool, which is mainly responsible for long-term stabilization of carbon in soils. These are aligned with selected general' soil properties such as pH, CEC and texture.

Specifics of soil temperature under winter oilseed rape canopy

Science.gov (United States)

Krčmářová, Jana; Středa, Tomáš; Pokorný, Radovan

2014-09-01

The aim of this study was to evaluate the course of soil temperature under the winter oilseed rape canopy and to determine relationships between soil temperature, air temperature and partly soil moisture. In addition, the aim was to describe the dependence by means of regression equations usable for pests and pathogens prediction, crop development, and yields models. The measurement of soil and near the ground air temperatures was performed at the experimental field Žabiče (South Moravia, the Czech Republic). The course of temperature was determined under or in the winter oilseed rape canopy during spring growth season in the course of four years (2010 - 2012 and 2014). In all years, the standard varieties (Petrol, Sherpa) were grown, in 2014 the semi-dwarf variety PX104 was added. Automatic soil sensors were positioned at three depths (0.05, 0.10 and 0.20 m) under soil surface, air temperature sensors in 0.05 m above soil surfaces. The course of soil temperature differs significantly between standard (Sherpa and Petrol) and semi-dwarf (PX104) varieties. Results of the cross correlation analysis showed, that the best interrelationships between air and soil temperature were achieved in 2 hours delay for the soil temperature in 0.05 m, 4 hour delay for 0.10 m and 7 hour delay for 0.20 m for standard varieties. For semi-dwarf variety, this delay reached 6 hour for the soil temperature in 0.05 m, 7 hour delay for 0.10 m and 11 hour for 0.20 m. After the time correction, the determination coefficient (R2) reached values from 0.67 to 0.95 for 0.05 m, 0.50 to 0.84 for 0.10 m in variety Sherpa during all experimental years. For variety PX104 this coefficient reached values from 0.51 to 0.72 in 0.05 m depth and from 0.39 to 0.67 in 0.10 m depth in the year 2014. The determination coefficient in the 0.20 m depth was lower for both varieties; its values were from 0.15 to 0.65 in variety Sherpa. In variety PX104 the values of R2 from 0.23 to 0.57 were determined. When using

Sand and clay mineralogy of sal forest soils of the Doon Siwalik ...

Indian Academy of Sciences (India)

3Forest Soil & Land Reclamation Division, Forest Research Institute, Dehradun 248 006, India. .... also helps in characterizing the soil mineralogical make-up in relation to the growth and develop- ment of the species essential for sustainable forest management. ...... and Weed S B (Madison: Soil Science Society of America).

Soil Taxonomy and land evaluation for forest establishment

Science.gov (United States)

Haruyoshi Ikawa

1992-01-01

Soil Taxonomy, the United States system of soil classification, can be used for land evaluation for selected purposes. One use is forest establishment in the tropics, and the soil family category is especially functional for this purpose. The soil family is a bionomial name with descriptions usually of soil texture, mineralogy, and soil temperature classes. If the...

A comparison of soil-moisture loss from forested and clearcut areas in West Virginia

Science.gov (United States)

Charles A. Troendle

1970-01-01

Soil-moisture losses from forested and clearcut areas were compared on the Fernow Experimental Forest. As expected, hardwood forest soils lost most moisture while revegetated clearcuttings, clearcuttings, and barren areas lost less, in that order. Soil-moisture losses from forested soils also correlated well with evapotranspiration and streamflow.

Comparison of the Chemical Properties of Forest Soil from the Silesian Beskid, Poland

Directory of Open Access Journals (Sweden)

Maria Zołotajkin

2014-01-01

Full Text Available There is spruce forests degradation observed in the Silesian Beskid. The aim of the work was the assessment of parameters diversifying organic layers of soils in two forest areas: degraded and healthy spruce forests of Silesian Beskid. 23 soil samples were collected from two fields—14 soil samples from a degraded forest and 9 soil samples from a forest, where pandemic dying of spruce is not observed. Implementation of hierarchical clustering to experimental data analysis allowed drawing a conclusion that the two forest areas vary significantly in terms of content of aluminium extracted with solutions of barium chloride (Alexch, sodium diphosphate (Alpyr, and pHKCl and in the amount of humus in soil.

Drivers of methane uptake by montane forest soils in the Peruvian Andes

Science.gov (United States)

Jones, Sam; Diem, Torsten; Huaraca Quispe, Lidia; Cahuana, Adan; Meir, Patrick; Teh, Yit

2016-04-01

The exchange of methane between the soils of humid tropical forests and the atmosphere is relatively poorly documented. This is particularly true of montane settings where variations between uptake and emission of atmospheric methane have been observed. Whilst most of these ecosystems appear to function as net sinks for atmospheric methane, some act as considerable sources. In regions like the Andes, humid montane forests are extensive and a better understanding of the magnitude and controls on soil-atmosphere methane exchange is required. We report methane fluxes from upper montane cloud forest (2811 - 2962 m asl), lower montane cloud forest (1532 - 1786 m asl), and premontane forest (1070 - 1088 m asl) soils in south-eastern Peru. Between 1000 and 3000 m asl, mean annual air temperature and total annual precipitation decrease from 24 ° C and 5000 mm to 12 ° C and 1700 mm. The study region experiences a pronounced wet season between October and April. Monthly measurements of soil-atmosphere gas exchange, soil moisture, soil temperature, soil oxygen concentration, available ammonium and available nitrate were made from February 2011 in the upper and lower montane cloud forests and July 2011 in the premontane forest to June 2013. These soils acted as sinks for atmospheric methane with mean net fluxes for wet and dry season, respectively, of -2.1 (0.2) and -1.5 (0.1) mg CH4 m-2 d-1 in the upper montane forest; -1.5 (0.2) and -1.4 (0.1) mg CH4 m-2 d-1in the lower montane forest; and -0.3 (0.2) and -0.2 (0.2) mg CH4 m-2 d-1 in the premontane forest. Spatial variations among forest types were related to available nitrate and water-filled pore space suggesting that nitrate inhibition of oxidation or constraints on the diffusional supply of methane to methanotrophic communities may be important controls on methane cycling in these soils. Seasonality in methane exchange, with weaker uptake related to increased water-filled pore space and soil temperature during the wet

Effects of over-winter green cover on soil solution nitrate concentrations beneath tillage land.

Science.gov (United States)

Premrov, Alina; Coxon, Catherine E; Hackett, Richard; Kirwan, Laura; Richards, Karl G

2014-02-01

There is a growing need to reduce nitrogen losses from agricultural systems to increase food production while reducing negative environmental impacts. The efficacy of vegetation cover for reducing nitrate leaching in tillage systems during fallow periods has been widely investigated. Nitrate leaching reductions by natural regeneration (i.e. growth of weeds and crop volunteers) have been investigated to a lesser extent than reductions by planted cover crops. This study compares the efficacy of natural regeneration and a sown cover crop (mustard) relative to no vegetative cover under both a reduced tillage system and conventional plough-based system as potential mitigation measures for reducing over-winter soil solution nitrate concentrations. The study was conducted over three winter fallow seasons on well drained soil, highly susceptible to leaching, under temperate maritime climatic conditions. Mustard cover crop under both reduced tillage and conventional ploughing was observed to be an effective measure for significantly reducing nitrate concentrations. Natural regeneration under reduced tillage was found to significantly reduce the soil solution nitrate concentrations. This was not the case for the natural regeneration under conventional ploughing. The improved efficacy of natural regeneration under reduced tillage could be a consequence of potential stimulation of seedling germination by the autumn reduced tillage practices and improved over-winter plant growth. There was no significant effect of tillage practices on nitrate concentrations. This study shows that over winter covers of mustard and natural regeneration, under reduced tillage, are effective measures for reducing nitrate concentrations in free draining temperate soils. © 2013.

Fumigant distribution in forest nursery soils

Science.gov (United States)

Dong Wang; Stephen W. Fraedrich; Jennifer Juzwik; Kurt Spokas; Yi Zhang; William C. Koskinen

2006-01-01

Adequate concentration, exposure time and distribution uniformity of activated fumigant gases are prerequisites for successful soil fumigation. Field experiments were conducted to evaluate gas phase distributions of methyl isothiocyanate (MITC) and chloropicrin (CP) in two forest-tree nurseries. Concentrations of MITC and CP in soil air were measured from replicated...

Measurements of flux and isotopic composition of soil carbon dioxide

International Nuclear Information System (INIS)

Gorczyca, Z.; Rozanski, K.; Kuc, T.

2002-01-01

The flux and isotope composition of soil CO 2 has been regularly measured at three sites located in the southern Poland, during the time period: January 1998 - October 2000. They represent typical ecosystems appearing in central Europe: (i) mixed forest; (ii) cultivated agricultural field; (iii) grassland. To monitor the flux and isotopic composition of soil CO 2 , a method based on the inverted cup principle was adopted. The flux of soil CO 2 reveals distinct seasonal fluctuations, with maximum values up to ca. 25 mmol/m 2 /h during sommer months and around ten times lower values during winter time. Also significant differences among the monitored sites were detected, the flux density of this gas being highest for the mixed forest site and ca. two times lower for the cultivated grassland. Carbon-13 content of the soil CO 2 reveals little seasonal variability, with δ 13 C values essentially reflecting the isotopic composition of the soil organic matter and the vegetation type. The carbon-14 content of soil CO 2 flux also reveals slight seasonality, with lower δ 14 C values recorded during winter time. Significantly lower δ 14 C values recorded during winter time. Significantly lower δ 14 C values were recorded at depth. (author)

Logging effects on soil moisture losses

Science.gov (United States)

Robert R. Ziemer

1978-01-01

Abstract - The depletion of soil moisture within the surface 15 feet by an isolated mature sugar pine and an adjacent uncut forest in the California Sierra Nevada was measured by the neutron method every 2 weeks for 5 consecutive summers. Soil moisture recharge was measured periodically during the intervening winters. Groundwater fluctuations within the surface 50...

Winter Responses of Forest Birds to Habitat Corridors and Gaps

Directory of Open Access Journals (Sweden)

Colleen Cassady St. Clair

1998-12-01

Full Text Available Forest fragmentation and habitat loss may disrupt the movement or dispersal of forest-dwelling birds. Despite much interest in the severity of these effects and ways of mitigating them, little is known about actual movement patterns in different habitat types. We studied the movement of wintering resident birds, lured by playbacks of mobbing calls, to compare the willingness of forest birds to travel various distances in continuous forest, along narrow corridors (fencerows, and across gaps in forest cover. We also quantified the willingness of Black-capped Chickadees (Poecile atricapillus to cross gaps when alternative forested detour routes were available. All species were less likely to respond to the calls as distance increased to 200 m, although White-breasted Nuthatches (Sitta carolinensis and Hairy Woodpeckers (Picoides villosus were generally less likely to respond than chickadees and Downy Woodpeckers (P. pubescens. Chickadees were as likely to travel in corridors as in continuous forest, but were less likely to cross gaps as the gap distance increased. The other species were less willing to travel in corridors and gaps relative to forest, and the differences among habitats also increased with distance. For chickadees, gap-crossing decisions in the presence of forested detours varied over the range of distances that we tested, and were primarily influenced by detour efficiency (the length of the shortcut relative to the available detour. Over short distances, birds used forested detours, regardless of their efficiency. As absolute distances increased, birds tended to employ larger shortcuts in the open when detour efficiency was low or initial distance in the open was high, but they limited their distance from the nearest forest edge to 25 m. Thus, chickadees were unwilling to cross gaps of > 50 m when they had forested alternatives, yet they sometimes crossed gaps as large as 200 m when no such choice existed. Our results suggest that

A three-dimensional stochastic model of the behavior of radionuclides in forests. Part 2. Cs-137 behavior in forest soils

International Nuclear Information System (INIS)

Berg, Mitchell T.; Shuman, Larry J.

1995-01-01

Using a three-dimensional stochastic model of radionuclides in forests developed in Part 1, this work simulates the long-term behavior of Cs-137 in forest soil. It is assumed that the behavior of Cs-137 in soils is driven by its advection and dispersion due to the infiltration of the soil solution, and its sorption to the soil matrix. As Cs-137 transport through soils is affected by its uptake and release by forest vegetation, a model of radiocesium behavior in forest vegetation is presented in Part 3 of this paper. To estimate the rate of infiltration of water through the soil, models are presented to estimate the hydrological cycle of the forest including infiltration, evapotranspiration, and the root uptake of water. The state transition probabilities for the random walk model of Cs-137 transport are then estimated using the models developed to predict the distribution of water in the forest. The random walk model is then tested using a base line scenario in which Cs-137 is deposited into a coniferous forest ecosystem

Fine root dynamics for forests on contrasting soils in the Colombian Amazon

Directory of Open Access Journals (Sweden)

E. M. Jiménez

2009-12-01

Full Text Available It has been hypothesized that as soil fertility increases, the amount of carbon allocated to below-ground production (fine roots should decrease. To evaluate this hypothesis, we measured the standing crop fine root mass and the production of fine roots (<2 mm by two methods: (1 ingrowth cores and, (2 sequential soil coring, during 2.2 years in two lowland forests growing on different soils types in the Colombian Amazon. Differences of soil resources were defined by the type and physical and chemical properties of soil: a forest on clay loam soil (Endostagnic Plinthosol at the Amacayacu National Natural Park and, the other on white sand (Ortseinc Podzol at the Zafire Biological Station, located in the Forest Reservation of the Calderón River. We found that the standing crop fine root mass and the production was significantly different between soil depths (0–10 and 10–20 cm and also between forests. The loamy sand forest allocated more carbon to fine roots than the clay loam forest with the production in loamy sand forest twice (mean±standard error=2.98±0.36 and 3.33±0.69 Mg C ha⁻¹ yr⁻¹, method 1 and 2, respectively as much as for the more fertile loamy soil forest (1.51±0.14, method 1, and from 1.03±0.31 to 1.36±0.23 Mg C ha⁻¹ yr⁻¹, method 2. Similarly, the average of standing crop fine root mass was higher in the white-sands forest (10.94±0.33 Mg C ha⁻¹ as compared to the forest on the more fertile soil (from 3.04±0.15 to 3.64±0.18 Mg C ha⁻¹. The standing crop fine root mass also showed a temporal pattern related to rainfall, with the production of fine roots decreasing substantially in the dry period of the year 2005. These results suggest that soil resources may play an important role in patterns of carbon allocation to the production of fine roots in these forests as the proportion of carbon allocated to above- and below-ground organs is different

A Comparative Study of the Soil Fauna in forests and cultivated land on sandy soils in Suriname

NARCIS (Netherlands)

Drift, van der J.

1963-01-01

1. In the coastal area of Suriname the soil and surface fauna were studied in various types of agricultural land, and compared with the fauna in the adjacent forests. 2. In primeval forest the soil macroarthropods are less numerous than in secondary forest (Formicidae excluded). They range generally

Soil carbon storage following road removal and timber harvesting in redwood forests

Science.gov (United States)

Seney, Joseph; Madej, Mary Ann

2015-01-01

Soil carbon storage plays a key role in the global carbon cycle and is important for sustaining forest productivity. Removal of unpaved forest roads has the potential for increasing carbon storage in soils on forested terrain as treated sites revegetate and soil properties improve on the previously compacted road surfaces. We compared soil organic carbon (SOC) content at several depths on treated roads to SOC in adjacent second-growth forests and old-growth redwood forests in California, determined whether SOC in the upper 50 cm of soil varies with the type of road treatment, and assessed the relative importance of site-scale and landscape-scale variables in predicting SOC accumulation in treated road prisms and second-growth redwood forests. Soils were sampled at 5, 20, and 50 cm depths on roads treated by two methods (decommissioning and full recontouring), and in adjacent second-growth and old-growth forests in north coastal California. Road treatments spanned a period of 32 years, and covered a range of geomorphic and vegetative conditions. SOC decreased with depth at all sites. Treated roads on convex sites exhibited higher SOC than on concave sites, and north aspect sites had higher SOC than south aspect sites. SOC at 5, 20, and 50 cm depths did not differ significantly between decommissioned roads (treated 18–32 years previous) and fully recontoured roads (treated 2–12 years previous). Nevertheless, stepwise multiple regression models project higher SOC developing on fully recontoured roads in the next few decades. The best predictors for SOC on treated roads and in second-growth forest incorporated aspect, vegetation type, soil depth, lithology, distance from the ocean, years since road treatment (for the road model) and years since harvest (for the forest model). The road model explained 48% of the variation in SOC in the upper 50 cm of mineral soils and the forest model, 54%

Migration and health risks of nonylphenol and bisphenol a in soil-winter wheat systems with long-term reclaimed water irrigation.

Science.gov (United States)

Wang, Shiyu; Liu, Fei; Wu, Wenyong; Hu, Yaqi; Liao, Renkuan; Chen, Gaoting; Wang, Jiulong; Li, Jialin

2018-04-12

Reclaimed water reuse has become an important means of alleviating agricultural water shortage worldwide. However, the presence of endocrine disrupters has roused up considerable attention. Barrel test in farmland was conducted to investigate the migration of nonylphenol (NP) and bisphenol A (BPA) in soil-winter wheat system simulating reclaimed water irrigation. Additionally, the health risks on humans were assessed based on US EPA risk assessment model. The migration of NP and BPA decreased from the soil to the winter wheat; the biological concentration factors (BCFs) of NP and BPA in roots, stems, leaves, and grains all decreased with their added concentrations in soils. The BCFs of NP and BPA in roots were greatest (0.60-5.80 and 0.063-1.45, respectively). The average BCFs of NP and BPA in winter wheat showed negative exponential relations to their concentrations in soil. The amounts of NP and BPA in soil-winter wheat system accounted for 8.99-28.24% and 2.35-4.95%, respectively, of the initial amounts added into the soils. The hazard quotient (HQ) for children and adults ranged between 10 -6 and 1, so carcinogenic risks could be induced by ingesting winter wheat grains under long-term reclaimed water irrigation. Copyright © 2018 Elsevier Inc. All rights reserved.

Changes in soil moisture drive soil methane uptake along a fire regeneration chronosequence in a eucalypt forest landscape.

Science.gov (United States)

Fest, Benedikt; Wardlaw, Tim; Livesley, Stephen J; Duff, Thomas J; Arndt, Stefan K

2015-11-01

Disturbance associated with severe wildfires (WF) and WF simulating harvest operations can potentially alter soil methane (CH4 ) oxidation in well-aerated forest soils due to the effect on soil properties linked to diffusivity, methanotrophic activity or changes in methanotrophic bacterial community structure. However, changes in soil CH4 flux related to such disturbances are still rarely studied even though WF frequency is predicted to increase as a consequence of global climate change. We measured in-situ soil-atmosphere CH4 exchange along a wet sclerophyll eucalypt forest regeneration chronosequence in Tasmania, Australia, where the time since the last severe fire or harvesting disturbance ranged from 9 to >200 years. On all sampling occasions, mean CH4 uptake increased from most recently disturbed sites (9 year) to sites at stand 'maturity' (44 and 76 years). In stands >76 years since disturbance, we observed a decrease in soil CH4 uptake. A similar age dependency of potential CH4 oxidation for three soil layers (0.0-0.05, 0.05-0.10, 0.10-0.15 m) could be observed on incubated soils under controlled laboratory conditions. The differences in soil CH4 uptake between forest stands of different age were predominantly driven by differences in soil moisture status, which affected the diffusion of atmospheric CH4 into the soil. The observed soil moisture pattern was likely driven by changes in interception or evapotranspiration with forest age, which have been well described for similar eucalypt forest systems in south-eastern Australia. Our results imply that there is a large amount of variability in CH4 uptake at a landscape scale that can be attributed to stand age and soil moisture differences. An increase in severe WF frequency in response to climate change could potentially increase overall forest soil CH4 sinks. © 2015 John Wiley & Sons Ltd.

Ectomycorrhizal mats alter forest soil biogeochemistry

Science.gov (United States)

Laurel A. Kluber; Kathryn M. Tinnesand; Bruce A. Caldwell; Susie M. Dunham; Rockie R. Yarwood; Peter J. Bottomley; David D. Myrold

2010-01-01

Dense hyphal mats formed by ectomycorrhizal (EcM) fungi are prominent features in Douglas-fir forest ecosystems, and have been estimated to cover up to 40% of the soil surface in some forest stands. Two morphotypes of EcM mats have been previously described: rhizomorphic mats, which have thick hyphal rhizomorphs and are found primarily in the organic horizon, and...

Soil-mediated filtering organizes tree assemblages in regenerating tropical forests

NARCIS (Netherlands)

Pinho, Bruno Ximenes; Melo, de Felipe Pimentel Lopes; Arroyo-Rodríguez, Víctor; Pierce, Simon; Lohbeck, Madelon; Tabarelli, Marcelo

2018-01-01

Secondary forests are increasingly dominant in human-modified tropical landscapes, but the drivers of forest recovery remain poorly understood. Soil conditions influence plant community composition, and are expected to change over a gradient of succession. However, the role of soil conditions as

Water repellency of two forest soils after biochar addition

Science.gov (United States)

D. S. Page-Dumroese; P. R. Robichaud; R. E. Brown; J. M. Tirocke

2015-01-01

Practical application of black carbon (biochar) to improve forest soil may be limited because biochar is hydrophobic. In a laboratory, we tested the water repellency of biochar application (mixed or surface applied) to two forest soils of varying texture (a granitic coarse-textured Inceptisol and an ash cap fine-textured Andisol) at four different application rates (0...

Leaf Area Index (LAI Estimation of Boreal Forest Using Wide Optics Airborne Winter Photos

Directory of Open Access Journals (Sweden)

Pauline Stenberg

2009-12-01

Full Text Available A new simple airborne method based on wide optics camera is developed for leaf area index (LAI estimation in coniferous forests. The measurements are carried out in winter, when the forest floor is completely snow covered and thus acts as a light background for the hemispherical analysis of the images. The photos are taken automatically and stored on a laptop during the flights. The R2 value of the linear regression of the airborne and ground based LAI measurements was 0.89.

Forest Soil Bacteria: Diversity, Involvement in Ecosystem Processes, and Response to Global Change.

Science.gov (United States)

Lladó, Salvador; López-Mondéjar, Rubén; Baldrian, Petr

2017-06-01

The ecology of forest soils is an important field of research due to the role of forests as carbon sinks. Consequently, a significant amount of information has been accumulated concerning their ecology, especially for temperate and boreal forests. Although most studies have focused on fungi, forest soil bacteria also play important roles in this environment. In forest soils, bacteria inhabit multiple habitats with specific properties, including bulk soil, rhizosphere, litter, and deadwood habitats, where their communities are shaped by nutrient availability and biotic interactions. Bacteria contribute to a range of essential soil processes involved in the cycling of carbon, nitrogen, and phosphorus. They take part in the decomposition of dead plant biomass and are highly important for the decomposition of dead fungal mycelia. In rhizospheres of forest trees, bacteria interact with plant roots and mycorrhizal fungi as commensalists or mycorrhiza helpers. Bacteria also mediate multiple critical steps in the nitrogen cycle, including N fixation. Bacterial communities in forest soils respond to the effects of global change, such as climate warming, increased levels of carbon dioxide, or anthropogenic nitrogen deposition. This response, however, often reflects the specificities of each studied forest ecosystem, and it is still impossible to fully incorporate bacteria into predictive models. The understanding of bacterial ecology in forest soils has advanced dramatically in recent years, but it is still incomplete. The exact extent of the contribution of bacteria to forest ecosystem processes will be recognized only in the future, when the activities of all soil community members are studied simultaneously. Copyright © 2017 American Society for Microbiology.

Contributions of water supply from the weathered bedrock zone to forest soil quality

Science.gov (United States)

James H. Witty; Robert C. Graham; Kenneth R. Hubbert; James A. Doolittle; Jonathan A. Wald

2003-01-01

One measure of forest soil quality is the ability of the soil to support tree growth. In mediterranean-type ecosystems, such as most of California's forests, there is virtually no rainfall during the summer growing season, so trees must rely on water stored within the substrate. Water is the primary limitation to productivity in these forests. Many forest soils in...

[Diversity of soil nematode communities in the subalpine and alpine forests of western Sichuan, China.

Science.gov (United States)

Chen, Ya; Yang, Wan Qin; Wu, Fu Zhong; Yang, Fan; Lan, Li Ying; Liu, Yu Wei; Guo, Cai Hong; Tan, Bo

2017-10-01

In order to understand the diversity of soil nematodes in the subalpine/alpine forests of the eastern Qinghai-Tibet Plateau, soil nematodes in the primary forest, mixed forest and secondary forest of Abies faxoniana were extracted by elutriation and sugar-centrifugation method in July 2015, and the composition and structure characteristics of soil nematode communities were studied in the three forests at different altitudes. A total of 37950 soil nematodes were collected, which belonged to 20 families and 27 genera, and the mean density was 4217 ind·100 g -1 dry soil. Filenchus was the dominant genus in the primary forest, and Filenchus and Pararotylenchus in the mixed forest and secondary forest, respectively. The individual number of each dominant genus was significantly affected by forest type. All nematode individuals were classified into the four trophic groups of bacterivores, fungivores, plant-parasites and omnivore-predators. The fungivores were dominant in the primary and secondary forest and the bacterivores in the mixed forest. The number of soil nematode c-p (colonizer-persister) groups of c-p 1, c-p 2, c-p 3 and c-p 4 accounted for 6.1%, 51.1%, 30.0% and 12.7% of the total nematode abundance, respectively. The maturity index (MI), the total maturity index (∑MI) and the plant parasitic index (PPI) of soil nematodes decreased gradually with the increase of altitude. The nematode channel ratio in the mixed forest was higher than 0.5, but that in the primary forest and secondary forest was below 0.5. The forest type significantly affected the soil nematode maturity index and channel ratio, but the forest type, soil layer and their interaction had no significant effect on the diversity index. There were obvious diffe-rences in the composition, nutrient structure and energy flow channel of soil nematodes in the subalpine/alpine forests of western Sichuan, providing an important reference for understanding the function of soil nematodes in soil processes

Organic carbon stocks and sequestration rates of forest soils in Germany.

Science.gov (United States)

Grüneberg, Erik; Ziche, Daniel; Wellbrock, Nicole

2014-08-01

The National Forest Soil Inventory (NFSI) provides the Greenhouse Gas Reporting in Germany with a quantitative assessment of organic carbon (C) stocks and changes in forest soils. Carbon stocks of the organic layer and the mineral topsoil (30 cm) were estimated on the basis of ca. 1.800 plots sampled from 1987 to 1992 and resampled from 2006 to 2008 on a nationwide grid of 8 × 8 km. Organic layer C stock estimates were attributed to surveyed forest stands and CORINE land cover data. Mineral soil C stock estimates were linked with the distribution of dominant soil types according to the Soil Map of Germany (1 : 1 000 000) and subsequently related to the forest area. It appears that the C pool of the organic layer was largely depending on tree species and parent material, whereas the C pool of the mineral soil varied among soil groups. We identified the organic layer C pool as stable although C was significantly sequestered under coniferous forest at lowland sites. The mineral soils, however, sequestered 0.41 Mg C ha(-1) yr(-1) . Carbon pool changes were supposed to depend on stand age and forest transformation as well as an enhanced biomass input. Carbon stock changes were clearly attributed to parent material and soil groups as sandy soils sequestered higher amounts of C, whereas clayey and calcareous soils showed small gains and in some cases even losses of soil C. We further showed that the largest part of the overall sample variance was not explained by fine-earth stock variances, rather by the C concentrations variance. The applied uncertainty analyses in this study link the variability of strata with measurement errors. In accordance to other studies for Central Europe, the results showed that the applied method enabled a reliable nationwide quantification of the soil C pool development for a certain period. © 2014 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

A meta-analysis of soil microbial biomass responses to forest disturbances

Directory of Open Access Journals (Sweden)

Sandra Robin Holden

2013-06-01

Full Text Available Climate warming is likely to increase the frequency and severity of forest disturbances, with uncertain consequences for soil microbial communities and their contribution to ecosystem C dynamics. To address this uncertainty, we conducted a meta-analysis of 139 published soil microbial responses to forest disturbances. These disturbances included abiotic (fire, harvesting, storm and biotic (insect, pathogen disturbances. We hypothesized that soil microbial biomass would decline following forest disturbances, but that abiotic disturbances would elicit greater reductions in microbial biomass than biotic disturbances. In support of this hypothesis, across all published studies, disturbances reduced soil microbial biomass by an average of 29.4%. However, microbial responses differed between abiotic and biotic disturbances. Microbial responses were significantly negative following fires, harvest, and storms (48.7%, 19.1%, and 41.7% reductions in microbial biomass, respectively. In contrast, changes in soil microbial biomass following insect infestation and pathogen-induced tree mortality were non-significant, although biotic disturbances were poorly represented in the literature. When measured separately, fungal and bacterial responses to disturbances mirrored the response of the microbial community as a whole. Changes in microbial abundance following disturbance were significantly positively correlated with changes in microbial respiration. We propose that the differential effect of abiotic and biotic disturbances on microbial biomass may be attributable to differences in soil disruption and organic C removal from forests among disturbance types. Altogether, these results suggest that abiotic forest disturbances may significantly decrease soil microbial abundance, with corresponding consequences for microbial respiration. Further studies are needed on the effect of biotic disturbances on forest soil microbial communities and soil C dynamics.

Climate Warming Can Increase Soil Carbon Fluxes Without Decreasing Soil Carbon Stocks in Boreal Forests

Science.gov (United States)

Ziegler, S. E.; Benner, R. H.; Billings, S. A.; Edwards, K. A.; Philben, M. J.; Zhu, X.; Laganiere, J.

2016-12-01

Ecosystem C fluxes respond positively to climate warming, however, the net impact of changing C fluxes on soil organic carbon (SOC) stocks over decadal scales remains unclear. Manipulative studies and global-scale observations have informed much of the existing knowledge of SOC responses to climate, providing insights on relatively short (e.g. days to years) and long (centuries to millennia) time scales, respectively. Natural climate gradient studies capture integrated ecosystem responses to climate on decadal time scales. Here we report the soil C reservoirs, fluxes into and out of those reservoirs, and the chemical composition of inputs and soil organic matter pools along a mesic boreal forest climate transect. The sites studied consist of similar forest composition, successional stage, and soil moisture but differ by 5.2°C mean annual temperature. Carbon fluxes through these boreal forest soils were greatest in the lowest latitude regions and indicate that enhanced C inputs can offset soil C losses with warming in these forests. Respiration rates increased by 55% and the flux of dissolved organic carbon from the organic to mineral soil horizons tripled across this climate gradient. The 2-fold increase in litterfall inputs to these soils coincided with a significant increase in the organic horizon C stock with warming, however, no significant difference in the surface mineral soil C stocks was observed. The younger mean age of the mineral soil C ( 70 versus 330 YBP) provided further evidence for the greater turnover of SOC in the warmer climate soils. In spite of these differences in mean radiocarbon age, mineral SOC exhibited chemical characteristics of highly decomposed material across all regions. In contrast with depth trends in soil OM diagenetic indices, diagenetic shifts with latitude were limited to increases in C:N and alkyl to O-alkyl ratios in the overlying organic horizons in the warmer relative to the colder regions. These data indicate that the

[The concentration and distribution of 137Cs in soils of forest and agricultural ecosystems of Tula Region].

Science.gov (United States)

Lipatov, D N; Shcheglov, A I; Tsvetnova, O B

2007-01-01

The paper deals with a comparative study of 137Cs contamination in forest, old arable and cultivated soils of Tula Region. Initial interception of Chernobyl derived 137Cs is higher in forest ecosystems: oak-forest > birch-forest > pine-forest > agricultural ecosystems. Vertical migration of 137Cs in deeper layers of soils was intensive in agricultural ecosystems: cultivated soils > old arable soils > birch-forest soils > oak-forest soils > pine-forest soils. In study have been evaluated spatial variability of 137Cs in soil and asymmetrical distribution, that is a skew to the right. Spatial heterogeneity of 137Cs in agricultural soils is much lower than in forest soils. For cultivated soil are determined the rate of resuspension, which equal to 6.1 x 10(-4) day(-1). For forest soils are described the 137Cs concentration in litter of different ecosystems. The role of main accumulation and barrier of 137Cs retain higher layers of soils (horizon A1(A1E) in forest, horizon Ap in agricultural ecosystems) in long-term forecast after Chernobyl accident.

Forest soil biology-timber harvesting relationships: a perspective

Science.gov (United States)

M. F. Jurgensen; M. J. Larsen; A. E. Harvey

1979-01-01

Timber harvesting has a pronounced effect on the soil microflora by wood removal and changing properties. This paper gives a perspective on soil biology-harvesting relationships with emphasis on the northern Rocky Mountain region. Of special significance to forest management operations are the effects of soil micro-organisms on: the availability of soil nutrients,...

Thermal Characteristics and Bacterial Diversity of Forest Soil in the Haean Basin of Korea

OpenAIRE

Kim, Heejung; Lee, Jin-Yong; Lee, Kang-Kun

2014-01-01

To predict biotic responses to disturbances in forest environments, it is important to examine both the thermophysical properties of forest soils and the diversity of microorganisms that these soils contain. To predict the effects of climate change on forests, in particular, it is essential to understand the interactions between the soil surface, the air, and the biological diversity in the soil. In this study, the temperature and thermal properties of forest soil at three depths at a site in...

Retention of available P in acid soils of tropical and subtropical evergreen broad-leaved forests

Institute of Scientific and Technical Information of China (English)

CHEN Jianhui; ZOU Xiaoming; YANG Xiaodong

2007-01-01

Precipitation of mineral phosphate is often recognized as a factor of limiting the availability of P in acidic soils of tropical and subtropical forests.For this paper,we studied the extractable P pools and their transformation rates in soils of a tropical evergreen forest at Xishuangbanna and a subtropical montane wet forest at the Ailao Mountains in order to understand the biogeochemical processes regulating P availability in acidic soils.The two forests differ in forest humus layer;it is deep in the Ailao forest while little is present in the Xishuangbanna forest.The extractable P pools by resin and sodium-bicarbonate decreased when soil organic carbon content was reduced.The lowest levels of extractable P pools occurred in the surface (0-10 era) mineral soils of the Xishuangbanna forest.However,microbial P in the mineral soil of the Xishuangbauna forest was twice that in the Ailao forest.Potential rates of microbial P immobilization were greater than those of organic P mineralization in mineral soils for both forests.We suggest that microbial P immobilization plays an essential role in avoiding mineral P precipitation and retaining available P of plant in tropical acidic soils,whereas both floor mass accumulation and microbial P immobilization function benefit retaining plant available P in subtropical montane wet forests.

Winter ecology of a subalpine grassland: Effects of snow removal on soil respiration, microbial structure and function.

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Gavazov, Konstantin; Ingrisch, Johannes; Hasibeder, Roland; Mills, Robert T E; Buttler, Alexandre; Gleixner, Gerd; Pumpanen, Jukka; Bahn, Michael

2017-07-15

Seasonal snow cover provides essential insulation for mountain ecosystems, but expected changes in precipitation patterns and snow cover duration due to global warming can influence the activity of soil microbial communities. In turn, these changes have the potential to create new dynamics of soil organic matter cycling. To assess the effects of experimental snow removal and advanced spring conditions on soil carbon (C) and nitrogen (N) dynamics, and on the biomass and structure of soil microbial communities, we performed an in situ study in a subalpine grassland in the Austrian Alps, in conjunction with soil incubations under controlled conditions. We found substantial winter C-mineralisation and high accumulation of inorganic and organic N in the topsoil, peaking at snowmelt. Soil microbial biomass doubled under the snow, paralleled by a fivefold increase in its C:N ratio, but no apparent change in its bacteria-dominated community structure. Snow removal led to a series of mild freeze-thaw cycles, which had minor effects on in situ soil CO 2 production and N mineralisation. Incubated soil under advanced spring conditions, however, revealed an impaired microbial metabolism shortly after snow removal, characterised by a limited capacity for C-mineralisation of both fresh plant-derived substrates and existing soil organic matter (SOM), leading to reduced priming effects. This effect was transient and the observed recovery in microbial respiration and SOM priming towards the end of the winter season indicated microbial resilience to short-lived freeze-thaw disturbance under field conditions. Bacteria showed a higher potential for uptake of plant-derived C substrates during this recovery phase. The observed temporary loss in microbial C-mineralisation capacity and the promotion of bacteria over fungi can likely impede winter SOM cycling in mountain grasslands under recurrent winter climate change events, with plausible implications for soil nutrient availability and

Methods of soil resampling to monitor changes in the chemical concentrations of forest soils

Science.gov (United States)

Lawrence, Gregory B.; Fernandez, Ivan J.; Hazlett, Paul W.; Bailey, Scott W.; Ross, Donald S.; Villars, Thomas R.; Quintana, Angelica; Ouimet, Rock; McHale, Michael; Johnson, Chris E.; Briggs, Russell D.; Colter, Robert A.; Siemion, Jason; Bartlett, Olivia L.; Vargas, Olga; Antidormi, Michael; Koppers, Mary Margaret

2016-01-01

Recent soils research has shown that important chemical soil characteristics can change in less than a decade, often the result of broad environmental changes. Repeated sampling to monitor these changes in forest soils is a relatively new practice that is not well documented in the literature and has only recently been broadly embraced by the scientific community. The objective of this protocol is therefore to synthesize the latest information on methods of soil resampling in a format that can be used to design and implement a soil monitoring program. Successful monitoring of forest soils requires that a study unit be defined within an area of forested land that can be characterized with replicate sampling locations. A resampling interval of 5 years is recommended, but if monitoring is done to evaluate a specific environmental driver, the rate of change expected in that driver should be taken into consideration. Here, we show that the sampling of the profile can be done by horizon where boundaries can be clearly identified and horizons are sufficiently thick to remove soil without contamination from horizons above or below. Otherwise, sampling can be done by depth interval. Archiving of sample for future reanalysis is a key step in avoiding analytical bias and providing the opportunity for additional analyses as new questions arise.

Methods of Soil Resampling to Monitor Changes in the Chemical Concentrations of Forest Soils.

Science.gov (United States)

Lawrence, Gregory B; Fernandez, Ivan J; Hazlett, Paul W; Bailey, Scott W; Ross, Donald S; Villars, Thomas R; Quintana, Angelica; Ouimet, Rock; McHale, Michael R; Johnson, Chris E; Briggs, Russell D; Colter, Robert A; Siemion, Jason; Bartlett, Olivia L; Vargas, Olga; Antidormi, Michael R; Koppers, Mary M

2016-11-25

Recent soils research has shown that important chemical soil characteristics can change in less than a decade, often the result of broad environmental changes. Repeated sampling to monitor these changes in forest soils is a relatively new practice that is not well documented in the literature and has only recently been broadly embraced by the scientific community. The objective of this protocol is therefore to synthesize the latest information on methods of soil resampling in a format that can be used to design and implement a soil monitoring program. Successful monitoring of forest soils requires that a study unit be defined within an area of forested land that can be characterized with replicate sampling locations. A resampling interval of 5 years is recommended, but if monitoring is done to evaluate a specific environmental driver, the rate of change expected in that driver should be taken into consideration. Here, we show that the sampling of the profile can be done by horizon where boundaries can be clearly identified and horizons are sufficiently thick to remove soil without contamination from horizons above or below. Otherwise, sampling can be done by depth interval. Archiving of sample for future reanalysis is a key step in avoiding analytical bias and providing the opportunity for additional analyses as new questions arise.

Forest structure, diversity and soil properties in a dry tropical forest in Rajasthan, Western India

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J. I. Nirmal Kumar

2011-06-01

Full Text Available Structure, species composition, and soil properties of a dry tropical forest in Rajasthan Western India, were examined by establishment of 25 plots. The forest was characterized by a relatively low canopy and a large number of small-diameter trees. Mean canopy height for this forest was 10 m and stands contained an average of 995 stems ha-1 (= 3.0 cm DBH; 52% of those stems were smaller than 10 cm DBH. The total basal area was 46.35 m2ha-1, of which Tectona grandis L. contributed 48%. The forest showed high species diversity of trees. 50 tree species (= 3.0 cm DBH from 29 families were identified in the 25 sampling plots. T. grandis (20.81% and Butea monosperma (9% were the dominant and subdominant species in terms of importance value. The mean tree species diversity indices for the plots were 1.08 for Shannon diversity index (H´, 0.71 for equitability index (J´ and 5.57 for species richness index (S´, all of which strongly declined with the increase of importance value of the dominant, T. grandis. Measures of soil nutrients indicated low fertility, extreme heterogeneity. Regression analysis showed that stem density and the dominant tree height were significantly correlated with soil pH. There was a significant positive relationship between species diversity index and soil available P, exchangeable K+, Ca2+ (all p values < 0.001 and a negative relationship with N, C, C:N and C:P ratio. The results suggest that soil properties are major factors influencing forest composition and structure within the dry tropical forest in Rajasthan.

Aspen increase soil moisture, nutrients, organic matter and respiration in Rocky Mountain forest communities.

Science.gov (United States)

Buck, Joshua R; St Clair, Samuel B

2012-01-01

Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO(3) and NH(4) were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development.

Anoxic conditions drive phosphorus limitation in humid tropical forest soil microorganisms

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Gross, A.; Pett-Ridge, J.; Weber, P. K.; Blazewicz, S.; Silver, W. L.

2017-12-01

The elemental stoichiometry of carbon (C), nitrogen (N) and phosphorus (P) of soil microorganisms (C:N:P ratios) regulates transfers of energy and nutrients to higher trophic levels. In humid tropical forests that grow on P-depleted soils, the ability of microbes to concentrate P from their surroundings likely plays a critical role in P-retention and ultimately in forest productivity. Models predict that climate change will cause dramatic changes in rainfall patterns in the humid tropics and field studies have shown these changes can affect the redox state of tropical forest soils, influencing soil respiration and biogeochemical cycling. However, the responses of soil microorganisms to changing environmental conditions are not well known. Here, we incubated humid tropical soils under oxic or anoxic conditions with substrates differing in both C:P stoichiometry and lability, to assess how soil microorganisms respond to different redox regimes. We found that under oxic conditions, microbial C:P ratios were similar to the global optimal ratio (55:1), indicating most microbial cells can adapt to persistent aerated conditions in these soils. However, under anoxic conditions, the ability of soil microbes to acquire soil P declined and their C:P ratios shifted away from the optimal ratio. NanoSIMS elemental imaging of single cells extracted from soil revealed that under anoxic conditions, C:P ratios were above the microbial optimal value in 83% of the cells, in comparison to 41% under oxic conditions. These data suggest microbial growth efficiency switched from being energy limited under oxic conditions to P-limited under anoxic conditions, indicating that, microbial growth in low P humid tropical forests soils may be most constrained by P-limitation when conditions are oxygen-limited. We suggest that differential microbial responses to soil redox states could have important implications for productivity of humid tropical forests under future climate scenarios.

Threats to North American Forests from Southern Pine Beetle with Warming Winters

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Lesk, Corey; Coffel, Ethan; D'Amato, Anthony W.; Dodds, Kevin; Horton, Radley M.

2016-01-01

In coming decades, warmer winters are likely to lift range constraints on many cold-limited forest insects. Recent unprecedented expansion of the southern pine beetle (SPB, Dendroctonus frontalis) into New Jersey, New York, Connecticut, and Massachusetts in concert with warming annual temperature minima highlights the risk that this insect pest poses to the pine forests of the northern United States and Canada under continued climate change. Here we present the first projections of northward expansion in SPB-suitable climates using a statistical bioclimatic range modeling approach and current-generation general circulation model (GCM) output under the RCP 4.5 and 8.5 emissions scenarios. Our results show that by the middle of the 21st century, the climate is likely to be suitable for SPB expansion into vast areas of previously unaffected forests throughout the northeastern United States and into southeastern Canada. This scenario would pose a significant economic and ecological risk to the affected regions, including disruption oflocal ecosystem services, dramatic shifts in forest structure, and threats to native biodiversity.

Spatial and vertical distribution of mercury in upland forest soils across the northeastern United States

International Nuclear Information System (INIS)

Richardson, Justin B.; Friedland, Andrew J.; Engerbretson, Teresa R.; Kaste, James M.; Jackson, Brian P.

2013-01-01

Assessing current Hg pools in forest soils of the northeastern U.S. is important for monitoring changes in Hg cycling. The forest floor, upper and lower mineral horizons were sampled at 17 long-term upland forest sites across the northeastern U.S. in 2011. Forest floor Hg concentration was similar across the study region (274 ± 13 μg kg −1 ) while Hg amount at northern sites (39 ± 6 g ha −1 ) was significantly greater than at western sites (11 ± 4 g ha −1 ). Forest floor Hg was correlated with soil organic matter, soil pH, latitude and mean annual precipitation and these variables explained approximately 70% of the variability when multiple regressed. Mercury concentration and amount in the lower mineral soil was correlated with Fe, soil organic matter and latitude, corresponding with Bs horizons of Spodosols (Podzols). Our analysis shows the importance of regional and soil properties on Hg accumulation in forest soils. -- Highlights: •Mercury in the forest floor and mineral soil was quantified at 17 sites. •Concentrations and amounts were regressed with regional factors and soil properties. •Forest floor Hg was most explained by soil organic matter, pH, and precipitation. •Mineral soil Hg was explained by latitude, Fe concentration, and soil organic matter. •Mineral soil Hg was greatest in Bs horizons of Spodosols due to podzolization. -- Forest floor Hg was correlated with soil organic matter, pH, latitude, and mean annual precipitation. Mineral soil Hg was greatest in Bs horizons of Spodosols

DRAINMOD-FOREST: Integrated Modeling of Hydrology, Soil Carbon and Nitrogen Dynamics, and Plant Growth for Drained Forests.

Science.gov (United States)

Tian, Shiying; Youssef, Mohamed A; Skaggs, R Wayne; Amatya, Devendra M; Chescheir, G M

2012-01-01

We present a hybrid and stand-level forest ecosystem model, DRAINMOD-FOREST, for simulating the hydrology, carbon (C) and nitrogen (N) dynamics, and tree growth for drained forest lands under common silvicultural practices. The model was developed by linking DRAINMOD, the hydrological model, and DRAINMOD-N II, the soil C and N dynamics model, to a forest growth model, which was adapted mainly from the 3-PG model. The forest growth model estimates net primary production, C allocation, and litterfall using physiology-based methods regulated by air temperature, water deficit, stand age, and soil N conditions. The performance of the newly developed DRAINMOD-FOREST model was evaluated using a long-term (21-yr) data set collected from an artificially drained loblolly pine ( L.) plantation in eastern North Carolina, USA. Results indicated that the DRAINMOD-FOREST accurately predicted annual, monthly, and daily drainage, as indicated by Nash-Sutcliffe coefficients of 0.93, 0.87, and 0.75, respectively. The model also predicted annual net primary productivity and dynamics of leaf area index reasonably well. Predicted temporal changes in the organic matter pool on the forest floor and in forest soil were reasonable compared to published literature. Both predicted annual and monthly nitrate export were in good agreement with field measurements, as indicated by Nash-Sutcliffe coefficients above 0.89 and 0.79 for annual and monthly predictions, respectively. This application of DRAINMOD-FOREST demonstrated its capability for predicting hydrology and C and N dynamics in drained forests under limited silvicultural practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Contributions of Ectomycorrhizal Fungal Mats to Forest Soil Carbon Cycles

Science.gov (United States)

Kluber, L. A.; Phillips, C. L.; Myrold, D. D.; Bond, B. J.

2008-12-01

Ectomycorrhizal (EM) fungi are a prominent and ubiquitous feature of forest soils, forming symbioses with most tree species, yet little is known about the magnitude of their impact on forest carbon cycles. A subset of EM fungi form dense, perennial aggregations of hyphae, which have elevated respiration rates compared with neighboring non-mat soils. These mats are a foci of EM activity and thereby a natural laboratory for examining how EM fungi impact forest soils. In order to constrain the contributions of EM fungi to forest soil respiration, we quantified the proportion of respiration derived from EM mat soils in an old-growth Douglas-fir stand in western Oregon. One dominant genus of mat-forming fungi, Piloderma, covered 56% of the soil surface area. Piloderma mats were monitored for respiration rates over 15 months and found to have on average 10% higher respiration than non-mat soil. At the stand level, this amounts to roughly 6% of soil respiration due to the presence of Piloderma mats. We calculate that these mats may constitute 27% of autotrophic respiration, based on respiration rates from trenched plots in a neighboring forest stand. Furthermore, enzyme activity and microbial community profiles in mat and non-mat soil provide evidence that specialized communities utilizing chitin contribute to this increased efflux. With 60% higher chitinase activity in mats, the breakdown of chitin is likely an important carbon flux while providing carbon and nitrogen to the microbial communities associated with mats. Quantitative PCR showed similar populations of fungi and bacteria in mat and non-mat soils; however, community analysis revealed distinct fungal and bacterial communities in the two soil types. The higher respiration associated with EM mats does not appear to be due only to a proliferation of EM fungi, but to a shift in overall community composition to organisms that efficiently utilize the unique resources available within the mat, including plant and

Assessment of Soil Organic Carbon Stock of Temperate Coniferous Forests in Northern Kashmir

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Davood A. Dar

2015-02-01

Full Text Available  Soil organic carbon (SOC estimation in temperate forests of the Himalaya is important to estimate their contribution to regional, national and global carbon stocks. Physico chemical properties of soil were quantified to assess soil organic carbon density (SOC and SOC CO2 mitigation density at two soil depths (0-10 and 10-20 cms under temperate forest in the Northern region of Kashmir Himalayas India. The results indicate that conductance, moisture content, organic carbon and organic matter were significantly higher while as pH and bulk density were lower at Gulmarg forest site. SOC % was ranging from 2.31± 0.96 at Gulmarg meadow site to 2.31 ± 0.26 in Gulmarg forest site. SOC stocks in these temperate forests were from 36.39 ±15.40 to 50.09 ± 15.51 Mg C ha-1. The present study reveals that natural vegetation is the main contributor of soil quality as it maintained the soil organic carbon stock. In addition, organic matter is an important indicator of soil quality and environmental parameters such as soil moisture and soil biological activity change soil carbon sequestration potential in temperate forest ecosystems.DOI: http://dx.doi.org/10.3126/ije.v4i1.12186International Journal of Environment Volume-4, Issue-1, Dec-Feb 2014/15; page: 161-178

Bryophyte-dominated biological soil crusts mitigate soil erosion in an early successional Chinese subtropical forest

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S. Seitz

2017-12-01

Full Text Available This study investigated the development of biological soil crusts (biocrusts in an early successional subtropical forest plantation and their impact on soil erosion. Within a biodiversity and ecosystem functioning experiment in southeast China (biodiversity and ecosystem functioning (BEF China, the effect of these biocrusts on sediment delivery and runoff was assessed within micro-scale runoff plots under natural rainfall, and biocrust cover was surveyed over a 5-year period. Results showed that biocrusts occurred widely in the experimental forest ecosystem and developed from initial light cyanobacteria- and algae-dominated crusts to later-stage bryophyte-dominated crusts within only 3 years. Biocrust cover was still increasing after 6 years of tree growth. Within later-stage crusts, 25 bryophyte species were determined. Surrounding vegetation cover and terrain attributes significantly influenced the development of biocrusts. Besides high crown cover and leaf area index, the development of biocrusts was favoured by low slope gradients, slope orientations towards the incident sunlight and the altitude of the research plots. Measurements showed that bryophyte-dominated biocrusts strongly decreased soil erosion, being more effective than abiotic soil surface cover. Hence, their significant role in mitigating sediment delivery and runoff generation in mesic forest environments and their ability to quickly colonise soil surfaces after disturbance are of particular interest for soil erosion control in early-stage forest plantations.

Bryophyte-dominated biological soil crusts mitigate soil erosion in an early successional Chinese subtropical forest

Science.gov (United States)

Seitz, Steffen; Nebel, Martin; Goebes, Philipp; Käppeler, Kathrin; Schmidt, Karsten; Shi, Xuezheng; Song, Zhengshan; Webber, Carla L.; Weber, Bettina; Scholten, Thomas

2017-12-01

This study investigated the development of biological soil crusts (biocrusts) in an early successional subtropical forest plantation and their impact on soil erosion. Within a biodiversity and ecosystem functioning experiment in southeast China (biodiversity and ecosystem functioning (BEF) China), the effect of these biocrusts on sediment delivery and runoff was assessed within micro-scale runoff plots under natural rainfall, and biocrust cover was surveyed over a 5-year period. Results showed that biocrusts occurred widely in the experimental forest ecosystem and developed from initial light cyanobacteria- and algae-dominated crusts to later-stage bryophyte-dominated crusts within only 3 years. Biocrust cover was still increasing after 6 years of tree growth. Within later-stage crusts, 25 bryophyte species were determined. Surrounding vegetation cover and terrain attributes significantly influenced the development of biocrusts. Besides high crown cover and leaf area index, the development of biocrusts was favoured by low slope gradients, slope orientations towards the incident sunlight and the altitude of the research plots. Measurements showed that bryophyte-dominated biocrusts strongly decreased soil erosion, being more effective than abiotic soil surface cover. Hence, their significant role in mitigating sediment delivery and runoff generation in mesic forest environments and their ability to quickly colonise soil surfaces after disturbance are of particular interest for soil erosion control in early-stage forest plantations.

Forest Structure Affects Soil Mercury Losses in the Presence and Absence of Wildfire.

Science.gov (United States)

Homann, Peter S; Darbyshire, Robyn L; Bormann, Bernard T; Morrissette, Brett A

2015-11-03

Soil is an important, dynamic component of regional and global mercury (Hg) cycles. This study evaluated how changes in forest soil Hg masses caused by atmospheric deposition and wildfire are affected by forest structure. Pre and postfire soil Hg measurements were made over two decades on replicate experimental units of three prefire forest structures (mature unthinned, mature thinned, clear-cut) in Douglas-fir dominated forest of southwestern Oregon. In the absence of wildfire, O-horizon Hg decreased by 60% during the 14 years after clearcutting, possibly the result of decreased atmospheric deposition due to the smaller-stature vegetative canopy; in contrast, no change was observed in mature unthinned and thinned forest. Wildfire decreased O-horizon Hg by >88% across all forest structures and decreased mineral-soil (0 to 66 mm depth) Hg by 50% in thinned forest and clear-cut. The wildfire-associated soil Hg loss was positively related to the amount of surface fine wood that burned during the fire, the proportion of area that burned at >700 °C, fire severity as indicated by tree mortality, and soil C loss. Loss of soil Hg due to the 200,000 ha wildfire was more than four times the annual atmospheric Hg emissions from human activities in Oregon.

Study on the effect of organic fertilizers on soil organic matter and enzyme activities of soil in forest nursery

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Piaszczyk Wojciech

2017-09-01

Full Text Available The aim of the study was to assess the effects of organic fertilization on selected chemical properties of the soil and the activity of dehydrogenase and β-glucosidase in the soil of forest nursery. The main goal was to evaluate the role of organic fertilizers in carbon storage in the forest nursery soil. Sample plots were located in northern Poland in the Polanów Forest District on a forest nursery. Soil samples were collected from horizon 0–20 cm for laboratory analyzes. In soil samples pH, soil texture, and organic carbon, nitrogen, base cation contents, dehydrogenase activity and β-glucosidase activity were determined. The obtained results were used to evaluate the carbon storage. The results confirm the beneficial effect of the applied organic fertilizer on chemical properties of the soils under study and their biological activity. The applied organic fertilizers had an impact on increased accumulation of soil organic matter. In the soils investigated, there was an increase in the activity of such enzymes as dehydrogenases and β-glucosidase.

Contributions of ectomycorrhizal fungal mats to forest soil respiration

Science.gov (United States)

C. Phillips; L.A. Kluber; J.P. Martin; B.A. Caldwell; B.J. Bond

2012-01-01

Distinct aggregations of fungal hyphae and rhizomorphs, or “mats”, formed by some genera of ectomycorrhizal (EcM) fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in western Oregon to investigate whether there was...

Observing and modeling links between soil moisture, microbes and CH4 fluxes from forest soils

Science.gov (United States)

Christiansen, Jesper; Levy-Booth, David; Barker, Jason; Prescott, Cindy; Grayston, Sue

2017-04-01

Soil moisture is a key driver of methane (CH4) fluxes in forest soils, both of the net uptake of atmospheric CH4 and emission from the soil. Climate and land use change will alter spatial patterns of soil moisture as well as temporal variability impacting the net CH4 exchange. The impact on the resultant net CH4 exchange however is linked to the underlying spatial and temporal distribution of the soil microbial communities involved in CH4 cycling as well as the response of the soil microbial community to environmental changes. Significant progress has been made to target specific CH4 consuming and producing soil organisms, which is invaluable in order to understand the microbial regulation of the CH4 cycle in forest soils. However, it is not clear as to which extent soil moisture shapes the structure, function and abundance of CH4 specific microorganisms and how this is linked to observed net CH4 exchange under contrasting soil moisture regimes. Here we report on the results from a research project aiming to understand how the CH4 net exchange is shaped by the interactive effects soil moisture and the spatial distribution CH4 consuming (methanotrophs) and producing (methanogens). We studied the growing season variations of in situ CH4 fluxes, microbial gene abundances of methanotrophs and methanogens, soil hydrology, and nutrient availability in three typical forest types across a soil moisture gradient in a temperate rainforest on the Canadian Pacific coast. Furthermore, we conducted laboratory experiments to determine whether the net CH4 exchange from hydrologically contrasting forest soils responded differently to changes in soil moisture. Lastly, we modelled the microbial mediation of net CH4 exchange along the soil moisture gradient using structural equation modeling. Our study shows that it is possible to link spatial patterns of in situ net exchange of CH4 to microbial abundance of CH4 consuming and producing organisms. We also show that the microbial

[Soil meso- and micro-fauna community structures in different urban forest types in Shanghai, China.

Science.gov (United States)

Jin, Shi Ke; Wang, Juan Juan; Zhu, Sha; Zhang, Qi; Li, Xiang; Zheng, Wen Jing; You, Wen Hui

2016-07-01

Soil meso- and micro-fauna of four urban forest types in Shanghai were investigated in four months which include April 2014, July 2014, October 2014 and January 2015. A total of 2190 soil fauna individuals which belong to 6 phyla, 15 classes and 22 groups were collected. The dominant groups were Nematoda and Arcari, accounting for 56.0% and 21.8% of the total in terms of individual numbers respectively. The common groups were Enchytraeidae, Rotatoria, Collembola and Hymenoptera and they accounted for 18.7% of the total in terms of individual numbers. There was a significant difference (PMetasequoia glyptostroboides forest, the smallest in Cinnamomum camphora forest. The largest groupe number was found in near-nature forest, the smallest was found in M. glyptostroboides forest. There was obvious seasonal dynamics in each urban forest type and green space which had larger density in autumn and larger groupe number in summer and autumn. In soil profiles, the degree of surface accumulation of soil meso- and micro-fauna in C. camphora forest was higher than in other forests and the vertical distribution of soil meso- and micro-fauna in near-nature forest was relatively homogeneous in four layers. Density-group index was ranked as: near-nature forest (6.953)> C. camphora forest (6.351)> Platanus forest (6.313)>M. glyptostroboides forest (5.910). The community diversity of soil fauna in each vegetation type could be displayed preferably by this index. It could be inferred through redundancy analysis (RDA) that the soil bulk density, organic matter and total nitrogen were the main environmental factors influencing soil meso- and micro-fauna community structure in urban forest. The positive correlations occurred between the individual number of Arcari, Enchytraeidae and soil organic matter and total nitrogen, as well as between the individual number of Diptera larvae, Rotatoria and soil water content.

Nitrogen dynamics in oak forest soils along a historical deposition gradient

Science.gov (United States)

Ralph E. J. Boerner; Elaine Kennedy Sutherland

1995-01-01

This study quantified soil nutrient status and N mineralization/nitrification potentials in soils of oakdominated, unmanaged forest stands in seven experimental forests ranging along a historical and current acidic deposition gradient from southern Illinois to central West Virginia, U.S.A. Among these seven sites (that spanned 8.5º of longitude) soil pH and Ca...

[A comparative study on soil fauna in native secondary evergreen broad-leaved forest and Chinese fir plantation forests in subtropics].

Science.gov (United States)

Yan, Shaokui; Wang, Silong; Hu, Yalin; Gao, Hong; Zhang, Xiuyong

2004-10-01

In this study, we investigated the response of soil animal communities to the replacement of native secondary forest by Chinese fir plantation forest and successive rotation of Chinese fir in subtropics. Three adjacent forest stands, i.e., native secondary evergreen broad-leaved forest stand (control) and Chinese fir plantation stands of first (20 yr) and second (20 yr) rotations were selected for the comparison of soil fauna. All animals were extracted from the floor litter and 0-15 cm soil layer of the stands in Summer, 2003 by using Tullgren method, wet funnel method and hand-sorting method. Compared to two Chinese fir plantation forests, the native secondary evergreen broad-leaved forest had a higher abundance and a higher taxonomic diversity of animals in soil and litter, but there were no significant differences in the biomass and productivity of soil fauna between all study stands. The abundance or diversity did not differ significantly between the first rotation and second rotation stands, too. The results supported that vegetation cover might be one of the main forces driving the development of soil animal communities, and the effect of successive rotation of Chinese fir on the development of soil fauna was a slow-running process.

Alkali metals in fungi of forest soil

International Nuclear Information System (INIS)

Vinichuk, M.; Taylor, A.; Rosen, K.; Nikolova, I.; Johanson, K.J.

2009-01-01

The high affinity of forest soil fungi for alkali metals such as potassium, rubidium, caesium as well as radiocaesium is shown and discussed. Good positive correlation was found between K: Rb concentration ratios in soil and in fungi, when correlation between K: Cs concentration ratios was less pronounced. (LN)

Nitrogen release from forest soils containing sulfide-bearing sediments

Science.gov (United States)

Maileena Nieminen, Tiina; Merilä, Päivi; Ukonmaanaho, Liisa

2014-05-01

Soils containing sediments dominated by metal sulfides cause high acidity and release of heavy metals, when excavated or drained, as the aeration of these sediments causes formation of sulfuric acid. Consequent leaching of acidity and heavy metals can kill tree seedlings and animals such as fish, contaminate water, and corrode concrete and steel. These types of soils are called acid sulfate soils. Their metamorphic equivalents, such as sulfide rich black shales, pose a very similar risk of acidity and metal release to the environment. Until today the main focus in treatment of the acid sulfate soils has been to prevent acidification and metal toxicity to agricultural crop plants, and only limited attention has been paid to the environmental threat caused by the release of acidity and heavy metals to the surrounding water courses. Even less attention is paid on release of major nutrients, such as nitrogen, although these sediments are extremely rich in carbon and nitrogen and present a potentially high microbiological activity. In Europe, the largest cover of acid sulfate soils is found in coastal lowlands of Finland. Estimates of acid sulfate soils in agricultural use range from 1 300 to 3 000 km2, but the area in other land use classes, such as managed peatland forests, is presumably larger. In Finland, 49 500 km2 of peatlands have been drained for forestry, and most of these peatland forests will be at the regeneration stage within 10 to 30 years. As ditch network maintenance is often a prerequisite for a successful establishment of the following tree generation, the effects of maintenance operations on the quality of drainage water should be under special control in peatlands underlain by sulfide-bearing sediments. Therefore, identification of risk areas and effective prevention of acidity and metal release during drain maintenance related soil excavating are great challenges for forestry on coastal lowlands of Finland. The organic and inorganic nitrogen

Erosi Tanah Akibat Operasi Pemanenan Hutan (Soil Erosion Caused by Forest Harvesting Operations

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Ujang Suwarna

2011-05-01

Full Text Available Forest harvesting operation has been known as an activity that should be considered as the main cause of soil erosion. Indonesia, the second largest owner of tropical forest, should have a serious consideration to the operation.  Therefore, the study was conducted in logged over area of a natural production forest.  The objectives of the study was to examine level of soil erosion caused by forest harvesting operations and to analyze a strategy to control level of the erosion based on its influencing factors. The study showed that forest harvesting operations caused soil erosion.  Factors that influenced the high level of the erosion were high level of precipitation, lack on planning of forest harvesting operations, no applying treatment of cross drain and cover crop in the new skidding roads, no culture of carefulness in the operations, and low human resource capacity in applying environmentally friendly forest harvesting techniques. Keywords: soil erosion, forest harvesting, logged over area, skidding road

Maximum temperature accounts for annual soil CO2 efflux in temperate forests of Northern China

Science.gov (United States)

Zhou, Zhiyong; Xu, Meili; Kang, Fengfeng; Jianxin Sun, Osbert

2015-01-01

It will help understand the representation legality of soil temperature to explore the correlations of soil respiration with variant properties of soil temperature. Soil temperature at 10 cm depth was hourly logged through twelve months. Basing on the measured soil temperature, soil respiration at different temporal scales were calculated using empirical functions for temperate forests. On monthly scale, soil respiration significantly correlated with maximum, minimum, mean and accumulated effective soil temperatures. Annual soil respiration varied from 409 g C m−2 in coniferous forest to 570 g C m−2 in mixed forest and to 692 g C m−2 in broadleaved forest, and was markedly explained by mean soil temperatures of the warmest day, July and summer, separately. These three soil temperatures reflected the maximum values on diurnal, monthly and annual scales. In accordance with their higher temperatures, summer soil respiration accounted for 51% of annual soil respiration across forest types, and broadleaved forest also had higher soil organic carbon content (SOC) and soil microbial biomass carbon content (SMBC), but a lower contribution of SMBC to SOC. This added proof to the findings that maximum soil temperature may accelerate the transformation of SOC to CO2-C via stimulating activities of soil microorganisms. PMID:26179467

Using soil quality indicators for monitoring sustainable forest management

Science.gov (United States)

James A. Burger; Garland Gray; D. Andrew Scott

2010-01-01

Most private and public forest land owners and managers are compelled to manage their forests sustainably, which means management that is economically viable,environmentally sound, and socially acceptable. To meet this mandate, the USDA Forest Service protects the productivity of our nation’s forest soils by monitoring and evaluating management activities to ensure...

Soil microbial community successional patterns during forest ecosystem restoration.

Science.gov (United States)

Banning, Natasha C; Gleeson, Deirdre B; Grigg, Andrew H; Grant, Carl D; Andersen, Gary L; Brodie, Eoin L; Murphy, D V

2011-09-01

Soil microbial community characterization is increasingly being used to determine the responses of soils to stress and disturbances and to assess ecosystem sustainability. However, there is little experimental evidence to indicate that predictable patterns in microbial community structure or composition occur during secondary succession or ecosystem restoration. This study utilized a chronosequence of developing jarrah (Eucalyptus marginata) forest ecosystems, rehabilitated after bauxite mining (up to 18 years old), to examine changes in soil bacterial and fungal community structures (by automated ribosomal intergenic spacer analysis [ARISA]) and changes in specific soil bacterial phyla by 16S rRNA gene microarray analysis. This study demonstrated that mining in these ecosystems significantly altered soil bacterial and fungal community structures. The hypothesis that the soil microbial community structures would become more similar to those of the surrounding nonmined forest with rehabilitation age was broadly supported by shifts in the bacterial but not the fungal community. Microarray analysis enabled the identification of clear successional trends in the bacterial community at the phylum level and supported the finding of an increase in similarity to nonmined forest soil with rehabilitation age. Changes in soil microbial community structure were significantly related to the size of the microbial biomass as well as numerous edaphic variables (including pH and C, N, and P nutrient concentrations). These findings suggest that soil bacterial community dynamics follow a pattern in developing ecosystems that may be predictable and can be conceptualized as providing an integrated assessment of numerous edaphic variables.

Associations between soil variables and vegetation structure and composition of Caribbean dry forests

Science.gov (United States)

Elvia M. Melendez-Ackerman; Julissa Rojas-Sandoval; Danny S. Fernandez; Grizelle Gonzalez; Hana Lopez; Jose Sustache; Mariely Morales; Miguel Garcia-Bermudez; Susan Aragon

2016-01-01

Soil–vegetation associations have been understudied in tropical dry forests when compared to the amount of extant research on this issue in tropical wet forests. Recent studies assert that vegetation in tropical dry forests is highly heterogeneous and that soil variability may be a contributing factor. In this study, we evaluated the relationship between soil variables...

Survival of rapidly fluctuating natural low winter temperatures by High Arctic soil invertebrates

DEFF Research Database (Denmark)

Convey, Peter; Abbandonato, Holly; Bergan, Frode

2015-01-01

The extreme polar environment creates challenges for its resident invertebrate communities and the stress tolerance of some of these animals has been examined over many years. However, although it is well appreciated that standard air temperature records often fail to describe accurately conditions...... microhabitats. To assess survival of natural High Arctic soil invertebrate communities contained in soil and vegetation cores to natural winter temperature variations, the overwintering temperatures they experienced were manipulated by deploying cores in locations with varying snow accumulation: No Snow...... and did not decrease below -12. °C. Those under deep snow were even more stable and did not decline below -2. °C. Despite these striking differences in winter thermal regimes, there were no clear differences in survival of the invertebrate fauna between treatments, including oribatid, prostigmatid...

Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

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Antônio Ocimar Manzi

2011-04-01

Full Text Available Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundwater chemistry and soil CO2 respiration were studied in forests on sandy soils, whereas drought sensitivity of poorly-drained valley soils was investigated in an artificial drainage experiment. Slightly changes in litter decomposition or water chemistry were observed as a consequence of artificial drainage. Riparian plots did experience higher litter decomposition rates than campina forest. In response to a permanent lowering of the groundwater level from 0.1 m to 0.3 m depth in the drainage plot, topsoil carbon and nitrogen contents decreased substantially. Soil CO2 respiration decreased from 3.7±0.6 µmol m-2 s-1 before drainage to 2.5±0.2 and 0.8±0.1 µmol m-2 s-1 eight and 11 months after drainage, respectively. Soil respiration in the control plot remained constant at 3.7±0.6 µmol m-2 s-1. The above suggests that more frequent droughts may affect topsoil carbon and nitrogen content and soil respiration rates in the riparian ecosystem, and may induce a transition to less diverse campinarana or short-statured campina forest that covers areas with strongly-leached sandy soil.

Soil and saproxylic species (Coleoptera, Collembola, Araneae in primeval forests from the Northern part of South-Easthern Carpathians

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Eugen Nițu

2009-12-01

Full Text Available In 2006-2007 we carried out faunal investigations in the vernal, estival and autumnal seasons in the scientific reserve "Codrul Secular Giumalău" using quantitative sampling methods. We identified 189 species of Coleoptera, 70 of Collembola and 20 of Araneae. Of these, 11 phytophagous, 18 myceto/xylo-mycetophagous, 9 mixophagous, 18 xylo- and cambio-xylemophagous, 38 saproxylophagous, 125 (55 Coleoptera, 70 Collembola detritivorous (sapro-, copro- and necrophagous, 60 (40 Coleoptera, 20 Aranea predators/parasitoids. Hymenaphorura polonica Pomorski, 1990 (Collembola, and Leiodes rhaeticus Erichson, 1845 (Coleoptera, Leiodidae, are recorded for the first time in the Romanian fauna. The rare species and characteristic species for the old primeval spruce forests are analysed for each studied taxonomic group. The species richness and faunal diversity from the Giumalău primeval spruce forest are compared with those of other very well preserved forests from the Carpathians scientific reserves (Codrul Secular Slătioara, Pietrosul Rodnei. The species abundances were used to compute the similarity indexes between the sampled sectors of forest and to perform Cluster Analysis. We observed that the dead wood in the 2nd-6th phases of decomposition has a great influence not only on the saproxylic species but also on the soil fauna like ground beetles (Carabidae that use the logs as ecologic microrefuges (winter refugees or diurnal refugees. The structure of the soil fauna is influenced by wood extraction from the forest ecosystem or by natural perturbations, this consisting in the appearance of opportunistic species as Orchesella pontica (Collembola and in decreasing of species richness of Carabidae (Coleoptera.

Soil and saproxylic species (Coleoptera, Collembola, Araneae in primeval forests from the northern part of South-Easthern Carpathians

Directory of Open Access Journals (Sweden)

Eugen Nitu

2009-11-01

Full Text Available In 2006-2007 we carried out faunal investigations in the vernal, estival and autumnal seasons in the scientific reserve "Codrul Secular Giumalãu" using quantitative sampling methods. We identified 189 species of Coleoptera, 70 of Collembola and 20 of Araneae. Of these, 11 phytophagous, 18 myceto/xylo-mycetophagous,9 mixophagous, 18 xylo- and cambio-xylemophagous, 38 saproxylophagous,125 (55 Coleoptera, 70 Collembola detritivorous (sapro-, copro- andnecrophagous, 60 (40 Coleoptera, 20 Aranea predators/parasitoids. Hymenaphorura polonica Pomorski, 1990 (Collembola, and Leiodes rhaeticus Erichson, 1845 (Coleoptera, Leiodidae, are recorded for the first time in the Romanian fauna. The rare species and characteristic species for the old primeval spruce forests are analysed for each studied taxonomic group. The species richness and faunal diversity from the Giumalãu primeval spruce forest are compared with those of other very well preserved forests from the Carpathians scientific reserves (Codrul Secular Slãtioara,Pietrosul Rodnei. The species abundances were used to compute the similarity indexes between the sampled sectors of forest and to perform Cluster Analysis. We observed that the dead wood in the 2nd-6th phases of decomposition has a great influence not only on the saproxylic species but also on the soil fauna like ground beetles(Carabidae that use the logs as ecologic microrefuges (winter refugees or diurnal refugees. The structure of the soil fauna is influenced by wood extraction from the forest ecosystem or by natural perturbations, this consisting in the appearance of opportunistic species as Orchesella pontica (Collembola and in decreasing ofspecies richness of Carabidae (Coleoptera.

[Contribution of soil water at various depths to water consumption of rainfed winter wheat in the Loess tableland, China].

Science.gov (United States)

Cheng, Li Ping; Liu, Wen Zhao

2017-07-18

Soil water and stem water were collected in jointing and heading stages of the rainfed winter wheat in the Changwu Loess tableland, and the stable isotopic compositions of hydrogen and oxygen in water samples were measured to analyze the contribution of soil water at various depths to water consumption of winter wheat. The results showed that the isotopes were enriched in soil and wheat stem water in comparison with that in precipitation. Under the condition of no dry layer in soil profile, the contributions to wheat water consumption in jointing and heading stages were 5.4% and 2.6% from soil water at 0-30 cm depth, 73.4% and 67.3% at 60-90 cm depth (the main water source for winter wheat), and 7.9% and 13.5% below 120 cm depth, respectively. With the wheat growth, the contribution of soil water below the depth of 90 cm increased. It was concluded that soil evaporation mainly consumed soil water in 0-30 cm depth and wheat transpiration mainly consumed soil water below 60 cm depth in the experimental period. In the production practice, it is necessary to increase rainwater storage ratio during the summer fallow period, and apply reasonable combination of nitrogen and phosphorus fertilizers in order to increase soil moisture before wheat sowing, promote the wheat root developing deep downwards and raise the deep soil water utilization ratio.

Soil seed banks along elevational gradients in tropical, subtropical and subalpine forests in Yunnan Province, southwest China

Institute of Scientific and Technical Information of China (English)

Xiaqin Luo; Min Cao; Min Zhang; Xiaoyang Song; Jieqiong Li; Akihiro Nakamura; Roger Kitching

2017-01-01

Soil seed banks are a vital part of ecosystems and influence community dynamics and regeneration.Although soil seed banks in different habitats have been reported,how soil seed banks vary with elerational gradients in different climatic zones is still unknown.This paper investigates seed density,species composition and nonconstituent species of forest soil seed banks in Yunnan Province,southwest China.Similarity between the soil seed bank and standing vegetation was also examined.We collected soil samples from sites spanning 12 elevations in tropical rain forests,subtropical evergreen broadleaved forests and subalpine coniferous forests,and transported them to a glasshouse for germination trials for species identification.The soil seed banks of tropical and subtropical forests had much higher seed densities and species richness than those of subalpine forests.Seeds of woody species dominated the soil seed banks of tropical and subtropical forests,while herbs dominated those of subalpine forests.The nonconstituent species in the soil seed banks were all herbs and were most abundant in tropical forests,followed by subtropical forests but were completely absent from subalpine forests.

Soil seed banks along elevational gradients in tropical, subtropical and subalpine forests in Yunnan Province, southwest China

Directory of Open Access Journals (Sweden)

Xiaqin Luo

2017-10-01

Full Text Available Soil seed banks are a vital part of ecosystems and influence community dynamics and regeneration. Although soil seed banks in different habitats have been reported, how soil seed banks vary with elevational gradients in different climatic zones is still unknown. This paper investigates seed density, species composition and nonconstituent species of forest soil seed banks in Yunnan Province, southwest China. Similarity between the soil seed bank and standing vegetation was also examined. We collected soil samples from sites spanning 12 elevations in tropical rain forests, subtropical evergreen broad-leaved forests and subalpine coniferous forests, and transported them to a glasshouse for germination trials for species identification. The soil seed banks of tropical and subtropical forests had much higher seed densities and species richness than those of subalpine forests. Seeds of woody species dominated the soil seed banks of tropical and subtropical forests, while herbs dominated those of subalpine forests. The nonconstituent species in the soil seed banks were all herbs and were most abundant in tropical forests, followed by subtropical forests but were completely absent from subalpine forests.

Effect of N and P addition on soil organic C potential mineralization in forest soils in South China

Institute of Scientific and Technical Information of China (English)

OUYANG Xuejun; ZHOU Guoyi; HUANG Zhongliang; ZHOU Cunyu; LI Jiong; SHI Junhui; ZHANG Deqiang

2008-01-01

Atmospheric nitrogen deposition is at a high level in some forests of South China. The effects of addition of exogenous N and P on soil organic carbon mineralization were studied to address: (1) if the atmospheric N deposition promotes soil C storage through decreasing mineralization; (2) if the soil available P is a limitation to organic carbon mineralization. Soils (0-10 cm) was sampled from monsoon evergreen broad-leaved forest (MEBF), coniferous and broad-leaved mixed forest (CBMF), and Pinus massoniana forest (PMF) in Dinghushan Biosphere Reserve (located in Gnangdong Province, China). The soils were incubated at 25℃ for 45 weeks, with addition of N (NH4NO3 solution) or P (KH2PO4 solution). CO2-C emission and the inorganic N (NH4+-N and NO3--N) of the soils were determined during the incubation. The results showed that CO2-C emission decreased with the N addition. The addition of P led to a short-term sharp increase in CO2 emission after P application, and the responses of CO2-C evolution to P addition in the later period of incubation related to forest types. Strong P inhibition to CO2 emission occurred in both PMF and CBMF soils in the later incubation. The two-pool kinetic model was fitted well to the data for C turnover in this experiment. The model analysis demonstrated that the addition of N and P changed the distribution of soil organic C between the labile and recalcitrant pool, as well as their mineralization rates. In our experiment, soil pH can not completely explain the negative effect of N addition on CO2-C emission. The changes of soil inorganic N during incubation seemed to support the hypothesis that the polymerization of added nitrogen with soil organic compound by abiotic reactions during incubation made the added nitrogen retard the soil organic carbon mineralization. We conclude that atmospheric N deposition contributes to soil C accretion in the three subtropical forest ecosystems, however, the shortage of soil available P in CBMF and

Transfer of radio-cesium from forest soil to woodchips using fungal activities

Science.gov (United States)

Kaneko, Nobuhiro; Huang, Yao; Tanaka, Yoichiro; Fujiwara, Yoshihiro; Sasaki, Michiko; Toda, Hiroto; Takahashi, Terumasa; Kobayashi, Tatsuaki; Harada, Naoki; Nonaka, Masahiro

2014-05-01

Raido-cesium released to terrestrial ecosystems by nuclear accidents is know to accumulate forest soil and organic layer on the soil. Forests in Japan are not exceptions. Practically it is impossible to decontaminate large area of forests. However, there is a strong demand from local people, who has been using secondary forests (Satoyama) around croplands in hilly areas, to decontaminate radio-cesium, because those people used to collect wild mushrooms and edible plants, and there are active cultures of mushrooms using logs and sawdusts. These natural resource uses consist substantial part of their economical activities, Therefore it is needed to decontaminate some selected part of forests in Japan to local economy. Clear cutting and scraping surface soil and organic matter are common methods of decontamination. However the efficiency of decontamination is up to 30% reduction of aerial radiation, and the cost to preserve contaminated debris is not affordable. In this study we used wood chips as a growth media for saprotrophic fungi which are known to accumulate redio-cesium. There are many studies indicated that mushrooms accumulated redio-cesium from forest soil and organic layer. It is not practical to collect mushrooms to decontaminate redio-cesium, because biomass of mushrooms are not enough to collect total contaminants. Mushrooms are only minor part of saprotrophic fungi. Fungal biomass in forest soil is about 1% of dead organic matter on forest floor. Our previous study to observe Cs accumulation to decomposing leaf litter indicated 18% absorption of total soil radio-Cs to litter during one year field incubation (Kaneko et al., 2013), and Cs concentration was proportional to fungal biomass on litter. This result indicated that fungi transferred radio-cesium around newly supplied leaf litter free of contamination. Therefore effective decontamination will be possible if we can provide large amount of growth media for saprotrophic fungi, and the media can be

Surface Runoff and Snowmelt Infiltration into the Soil on Plowlands in the Forest-Steppe and Steppe Zones of the East European Plain

Science.gov (United States)

Barabanov, A. T.; Dolgov, S. V.; Koronkevich, N. I.; Panov, V. I.; Petel'ko, A. I.

2018-01-01

Long-term series of observations over the spring water balance elements on fields with hydrologically contrasting agricultural backgrounds―a loose soil after fall moldboard plowing and a plowland compacted by 12-16% compared to the former soil (perennial grasses, winter crops, stubble)―have been analyzed. The values of surface runoff and water infiltration into the soil in the steppe and forest-steppe zones of European Russia have been calculated for the spring (flooding) period and the entire cold season. The hydrological role of fall plowing has been shown, and water balance elements for the current (1981-2016) and preceding (1957-1980) periods have been compared. A significant decrease in runoff and an increase of water reserve in the soil have been revealed on all plowland types. Consequences of changes in the spring water balance on plowland have been analyzed.

Nematodes inhabit soils of forest and clear-cut areas

Science.gov (United States)

Alex L. Shigo; George Yelenosky

1960-01-01

Nematodes are present in all forest soils, but their effects on forest trees are not known. The known destructive nature of these worms on other woody crops suggests that they may also be involved in causing some of the unexplainable losses in vigor and mortality of forest trees.

Tropical forest soil microbes and climate warming: An Andean-Amazon gradient and `SWELTR'

Science.gov (United States)

Nottingham, A.; Turner, B. L.; Fierer, N.; Whitaker, J.; Ostle, N. J.; McNamara, N. P.; Bardgett, R.; Silman, M.; Bååth, E.; Salinas, N.; Meir, P.

2017-12-01

Climate warming predicted for the tropics in the coming century will result in average temperatures under which no closed canopy forest exists today. There is, therefore, great uncertainty associated with the direction and magnitude of feedbacks between tropical forests and our future climate - especially relating to the response of soil microbes and the third of global soil carbon contained in tropical forests. While warming experiments are yet to be performed in tropical forests, natural temperature gradients are powerful tools to investigate temperature effects on soil microbes. Here we draw on studies from a 3.5 km elevation gradient - and 20oC mean annual temperature gradient - in Peruvian tropical forest, to investigate how temperature affects the structure of microbial communities, microbial metabolism, enzymatic activity and soil organic matter cycling. With decreased elevation, soil microbial diversity increased and community composition shifted, from taxa associated with oligotrophic towards copiotrophic traits. A key role for temperature in shaping these patterns was demonstrated by a soil translocation experiment, where temperature-manipulation altered the relative abundance of specific taxa. Functional implications of these community composition shifts were indicated by changes in enzyme activities, the temperature sensitivity of bacterial and fungal growth rates, and the presence of temperature-adapted iso-enzymes at different elevations. Studies from a Peruvian elevation transect indicated that soil microbial communities are adapted to long-term (differences with elevation) and short-term (translocation responses) temperature changes. These findings indicate the potential for adaptation of soil microbes in tropical soils to future climate warming. However, in order to evaluate the sensitivity of these processes to climate warming in lowland forests, in situ experimentation is required. Finally, we describe SWELTR (Soil Warming Experiment in Lowland

N2O production pathways in the subtropical acid forest soils in China

International Nuclear Information System (INIS)

Zhang Jinbo; Cai Zucong; Zhu Tongbin

2011-01-01

To date, N 2 O production pathways are poorly understood in the humid subtropical and tropical forest soils. A 15 N-tracing experiment was carried out under controlled laboratory conditions to investigate the processes responsible for N 2 O production in four subtropical acid forest soils (pH 2 O emission in the subtropical acid forest soils, being responsible for 56.1%, 53.5%, 54.4%, and 55.2% of N 2 O production, in the GC, GS, GB, and TC soils, respectively, under aerobic conditions (40%-52%WFPS). The heterotrophic nitrification (recalcitrant organic N oxidation) accounted for 27.3%-41.8% of N 2 O production, while the contribution of autotrophic nitrification was little in the studied subtropical acid forest soils. The ratios of N 2 O-N emission from total nitrification (heterotrophic+autotrophic nitrification) were higher than those in most previous references. The soil with the lowest pH and highest organic-C content (GB) had the highest ratio (1.63%), suggesting that soil pH-organic matter interactions may exist and affect N 2 O product ratios from nitrification. The ratio of N 2 O-N emission from heterotrophic nitrification varied from 0.02% to 25.4% due to soil pH and organic matter. Results are valuable in the accurate modeling of N2O production in the subtropical acid forest soils and global budget. - Highlights: → We studied N 2 O production pathways in subtropical acid forest soil under aerobic conditions. → Denitrification was the main source of N 2 O production in subtropical acid forest soils. → Heterotrophic nitrification accounted for 27.3%-41.8% of N 2 O production. → While, contribution of autotrophic nitrification to N 2 O production was little. → Ratios of N 2 O-N emission from nitrification were higher than those in most previous references.

Preliminary study of prairies forested with Eucalyptus sp. at the northwestern Uruguayan soils

International Nuclear Information System (INIS)

Carrasco-Letelier, L.; Eguren, G.; Castineira, C.; Parra, O.; Panario, D.

2004-01-01

The forestation of Uruguayan natural prairie soil does not always ensure an increase of soil carbon sink. - The land cover change of Uruguayan Forestal Plan provoked biogeochemical changes on horizon Au 1 of Argiudols; in native prairies which were replaced by monoculture Eucalyptus sp. plantation with 20 year rotations as trees. Five fields forested and six natural prairies were compared. The results not only show a statistical significant soil acidification, diminution of soil organic carbon, increase of aliphaticity degree of humic substances, and increase of affinity and capacity of hydrolytic activity from soil microbial communities for forested sites with Eucalyptus sp. but also, a tendency of podzolization and/or mineralization by this kind of land cover changes, with a net soil organic lost of 16.6 tons ha -1 in the horizon Au 1 of soil under Eucalyptus sp. plantation compared with prairie. Besides, these results point out the necessity of correction of the methodology used by assigned Uruguayan commission to assess the national net emission of greenhouse gases, since the mineralization and/or podzolization process detected in forested soil imply a overestimation of soil organic carbon. The biochemical parameters show a statistical significant correlation between the soil organic carbon status and these parameters which were presented as essential for the correct evaluation of Uruguayan soil carbon sink

Magnetic Soils Profiles in the Volga-Kama Forest-Steppe Region

Directory of Open Access Journals (Sweden)

L.A. Fattakhova

2016-09-01

Full Text Available The magnetic properties of virgin forest-steppe soils developed on the originally vertically uniform unconsolidated parent material have been investigated. The profile samples of virgin dark-grey forest light-clayey soil derived from a siltstone of the Kazan layer of the Upper Permian and virgin leached medium-thick fertile light-clayey chernozem derived from a Quaternary heavy deluvial loam have been considered. Both soils are characterized by the accumulative type of magnetic susceptibility and F-factor values distribution patterns with depth. In the humus part of the soil profile, magnetics are present pre-dominantly in the < 2.5 µm fraction. The coercivity spectra allowed to determine the contribution of dia-/paramagnetic and ferromagnetic components to magnetic susceptibility. It has been found that magnetic susceptibility enhancement in the organogenic horizons of virgin forest-steppe soils occurs due to the contribution of ferromagnetic components. The results indicate a strong positive linear correlation between the magnetic susceptibility and oxalate-extractable Fe, as well as between the magnetic susceptibility and Schwertmann’s criterion values. Using the method of thermomagnetic analysis of the < 2.5 µm fraction, it has been found that the magnetic susceptibility enhancement in the profiles of forest-steppe soils took place due to the formation of maghemite-magnetite associations. The predominantly ferromagnetic fraction consists of small single-domain grains.

Landscape heterogeneity, soil climate, and carbon exchange in a boreal black spruce forest.

Science.gov (United States)

Dunn, Allison L; Wofsy, Steven C; v H Bright, Alfram

2009-03-01

We measured soil climate and the turbulent fluxes of CO2, H2O, heat, and momentum on short towers (2 m) in a 160-yr-old boreal black spruce forest in Manitoba, Canada. Two distinct land cover types were studied: a Sphagnum-dominated wetland, and a feathermoss (Pleurozium and Hylocomium)-dominated upland, both lying within the footprint of a 30-m tower, which has measured whole-forest carbon exchange since 1994. Peak summertime uptake of CO2, was higher in the wetland than for the forest as a whole due to the influence of deciduous shrubs. Soil respiration rates in the wetland were approximately three times larger than in upland soils, and 30% greater than the mean of the whole forest, reflecting decomposition of soil organic matter. Soil respiration rates in the wetland were regulated by soil temperature, which was in turn influenced by water table depth through effects on soil heat capacity and conductivity. Warmer soil temperatures and deeper water tables favored increased heterotrophic respiration. Wetland drainage was limited by frost during the first half of the growing season, leading to high, perched water tables, cool soil temperatures, and much lower respiration rates than observed later in the growing season. Whole-forest evapotranspiration increased as water tables dropped, suggesting that photosynthesis in this forest was rarely subject to water stress. Our data indicate positive feedback between soil temperature, seasonal thawing, heterotrophic respiration, and evapotranspiration. As a result, climate warming could cause covariant changes in soil temperature and water table depths that may stimulate photosynthesis and strongly promote efflux of CO2 from peat soils in boreal wetlands.

Final Progress Report on Model-Based Diagnosis of Soil Limitations to Forest Productivity

Energy Technology Data Exchange (ETDEWEB)

Luxmoore, R.J.

2004-08-30

This project was undertaken in support of the forest industry to link modeling of nutrients and productivity with field research to identify methods for enhancing soil quality and forest productivity and for alleviating soil limitations to sustainable forest productivity. The project consisted of a series of related tasks, including (1) simulation of changes in biomass and soil carbon with nitrogen fertilization, (2) development of spreadsheet modeling tools for soil nutrient availability and tree nutrient requirements, (3) additional modeling studies, and (4) evaluation of factors involved in the establishment and productivity of southern pine plantations in seasonally wet soils. This report also describes the two Web sites that were developed from the research to assist forest managers with nutrient management of Douglas-fir and loblolly pine plantations.

Land use, forest density, soil mapping, erosion, drainage, salinity limitations

Science.gov (United States)

Yassoglou, N. J. (Principal Investigator)

1973-01-01

The author has identified the following significant results. The results of analyses show that it is possible to obtain information of practical significance as follows: (1) A quick and accurate estimate of the proper use of the valuable land can be made on the basis of temporal and spectral characteristics of the land features. (2) A rather accurate delineation of the major forest formations in the test areas was achieved on the basis of spatial and spectral characteristics of the studied areas. The forest stands were separated into two density classes; dense forest, and broken forest. On the basis of ERTS-1 data and the existing ground truth information a rather accurate mapping of the major vegetational forms of the mountain ranges can be made. (3) Major soil formations are mapable from ERTS-1 data: recent alluvial soils; soil on quarternary deposits; severely eroded soil and lithosol; and wet soils. (4) An estimation of cost benefits cannot be made accurately at this stage of the investigation. However, a rough estimate of the ratio of the cost for obtaining the same amount information from ERTS-1 data and from conventional operations would be approximately 1:6 to 1:10, in favor of the ERTS-1.

Forest Soil Productivity on the Southern Long-Term Soil Productivity Sites at Age 5

Science.gov (United States)

D. Andrew Scott; Allan E. Tiarks; Felipe G. Sanchez; Michael Elliott-Smith; Rick Stagg

2004-01-01

Forest management operations have the potential to reduce soil productivity through organic matter and nutrient removal and soil compaction. We measured pine volume, bulk density, and soil and foliar nitrogen and phosphorus at age 5 on the 13 southern Long-Term Soil Productivity study sites. The treatments were organic matter removal [bole only (BO), whole tree (WT),...

Natural and artificial radionuclides in forest and bog soils: tracers for migration processes and soil development

International Nuclear Information System (INIS)

Schleich, N.; Degering, D.; Unterricker, S.

2000-01-01

Radionuclide distributions in undisturbed forest and bog soils, mostly situated in Saxony, Germany (Erzgebirge), were studied. Low concentrations of naturally-occurring U and Th decay series nuclides, including 210 Pb, and artificial radioisotopes ( 125 Sb, 134 Cs, 137 Cs, 241 Am) were determined using low-level γ-spectrometry. In addition, the activities of 238 Pu and 239,240 Pu were determined by radiochemical separation and α-spectrometry. 14 C and excess 210 Pb dating methods were used to date the sampled bog profiles. The different radionuclides show characteristic depth distributions in the forest and bog soil horizons, which were sub-sampled as thin slices. 125 Sb, 241 Am, 238 Pu and 239,240 Pu are strongly fixed in soil organic matter. In spruce forest soils, the influence of soil horizons with distinct properties dominates the vertical time-dependent distribution. In ombrotrophic bogs, the peak positions correlated with the year of maximum input of each nuclide. The Sb, Am and Pu ''time markers'' and the 14 C and 210 Pb dating results correspond very well. Although Cs seems to be relatively mobile in organic as well as mineral forest soil horizons, it is enriched in the organic material. In ombrotrophic bogs, Cs is very mobile in the peat deposit. In Sphagnum peat, Cs is translocated continuously towards the growing apices of the Sphagnum mosses, where it is accumulated. (orig.)

Relative nitrogen mineralization and nitrification potentials in relation to soil chemistry in oak forest soils along a historical deposition gradient

Science.gov (United States)

Ralph E. J. Boerner; Elaine Kennedy Sutherland

1996-01-01

This study quantified soil nutrient status and N mineralization/nitrification potentials in soils of oak-dominated, unmanaged forest stands in seven USDA Forest Service experimental forests (EF) ranging along a historical and current acidic deposition gradient from southern Illinois to central West Virginia.

Dynamics of forest soil chemistry

Energy Technology Data Exchange (ETDEWEB)

Alveteg, M

1998-11-01

Acidification caused by emissions of nitrogen and sulphur and associated adverse effects on forest ecosystems has been an issue on the political agenda for decades. Temporal aspects of soil acidification and/or recovery can be investigated using the soil chemistry model SAFE, a dynamic version of the steady-state model PROFILE used in critical loads assessment on the national level, e.g. for Sweden. In this thesis, possibilities to replace the use of apparent gibbsite solubility coefficients with a more mechanistic Al sub-model are investigated and a reconstruction model, MAKEDEP, is presented which makes hindcasts and forecasts of atmospheric deposition and nutrient uptake and cycling. A regional application of SAFE/MAKEDEP based on 622 sites in Switzerland is also presented. It is concluded that the quantitative information on pools and fluxes of Al in forest ecosystems is very limited and that there currently exists no mechanistic alternative in modelling soil solution Al. MAKEDEP is a valuable and operational tool for deriving input to dynamic soil chemistry models such as SMART, MAGIC and SAFE. For multi-layer models, e.g. the SAFE model, including nutrient cycling in MAKEDEP is shown to be important. The strength of the regional assessment strategy presented in this thesis lies in its transparency and modularity. All sub-modules, including models, transfer functions, assumptions in the data acquisition strategy, etc., can be checked and replaced individually. As the presented assessment strategy is based on knowledge and data from a wide range of scientists and fields it is of vital importance that the research community challenge the assumptions made. The many measurable intermediate results produced by the included models will hopefully encourage scientists to challenge the models through additional measurements at the calculation sites. It is concluded that current reduction plans are not sufficient for all forest ecosystems in Switzerland to recover from

Divergent Responses of Forest Soil Microbial Communities under Elevated CO2 in Different Depths of Upper Soil Layers.

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Yu, Hao; He, Zhili; Wang, Aijie; Xie, Jianping; Wu, Liyou; Van Nostrand, Joy D; Jin, Decai; Shao, Zhimin; Schadt, Christopher W; Zhou, Jizhong; Deng, Ye

2018-01-01

Numerous studies have shown that the continuous increase of atmosphere CO 2 concentrations may have profound effects on the forest ecosystem and its functions. However, little is known about the response of belowground soil microbial communities under elevated atmospheric CO 2 (eCO 2 ) at different soil depth profiles in forest ecosystems. Here, we examined soil microbial communities at two soil depths (0 to 5 cm and 5 to 15 cm) after a 10-year eCO 2 exposure using a high-throughput functional gene microarray (GeoChip). The results showed that eCO 2 significantly shifted the compositions, including phylogenetic and functional gene structures, of soil microbial communities at both soil depths. Key functional genes, including those involved in carbon degradation and fixation, methane metabolism, denitrification, ammonification, and nitrogen fixation, were stimulated under eCO 2 at both soil depths, although the stimulation effect of eCO 2 on these functional markers was greater at the soil depth of 0 to 5 cm than of 5 to 15 cm. Moreover, a canonical correspondence analysis suggested that NO 3 -N, total nitrogen (TN), total carbon (TC), and leaf litter were significantly correlated with the composition of the whole microbial community. This study revealed a positive feedback of eCO 2 in forest soil microbial communities, which may provide new insight for a further understanding of forest ecosystem responses to global CO 2 increases. IMPORTANCE The concentration of atmospheric carbon dioxide (CO 2 ) has continuously been increasing since the industrial revolution. Understanding the response of soil microbial communities to elevated atmospheric CO 2 (eCO 2 ) is important for predicting the contribution of the forest ecosystem to global atmospheric change. This study analyzed the effect of eCO 2 on microbial communities at two soil depths (0 to 5 cm and 5 to 15 cm) in a forest ecosystem. Our findings suggest that the compositional and functional structures of microbial

Seasonal dynamics of soil CO2 emission in the boreal forests in Central Siberia

Science.gov (United States)

Makhnykina, A. V.; Prokishkin, A. S.; Zyryanov, V.; Verkhovets, S. V.

2016-12-01

A large amount of carbon in soil is released to the atmosphere through soil respiration, which is the main pathway of transferring carbon from terrestrial ecosystems (Comstedt et al., 2011). Considering that boreal forests is a large terrestrial sink (Tans et al., 1990) and represent approximately 11 % of the Earth's total land area (Gower et al., 2001), even a small change in soil respiration could significantly intensify - or mitigate - current atmospheric increases of CO2, with potential feedbacks to climate change. The objectives of the present study are: (a) to study the dynamic of CO2emission from the soil surface during summer season (from May to October); (b) to identify the reaction of soil respiration to different amount of precipitation as the main limiting factor in the region. The research was carried out in the pine forests in Central Siberia (60°N, 90°E), Russia. Sample plots were represented by the lichen pine forest, moss pine forest, mixed forest and anthropogenic destroyed area. We used the automated soil CO2 flux system based on the infrared gas analyzer LI-8100 for measuring the soil efflux. Soil temperature was measured with Soil Temperature Probe Type E in three depths 5, 10, 15 cm. Volumetric soil moisture was measured with Theta Probe Model ML2. The presence and type of ground cover substantially affects the value of soil respiration fluxes. The carbon dioxide emission from the soil surface averaged was 5.4 ±2.3 μmol CO2 m-2 s-1. The destroyed area without plant cover demonstrated the lowest soil respiration (0.1-5.6 μmol CO2 m-2 s-1). The lowest soil respiration among forested areas was observed in the feathermoss pine forest. The lichen pine forest soil respiration was characterized by averages values. The maximum soil respiration values and seasonal fluctuations were obtained in the mixed forest (2.3-29.3 μmol CO2 m-2 s-1). The analysis of relation between soil CO2 efflux and amount of precipitation showed that the site without any

Why Do Some Evergreen Species Keep Their Leaves for a Second Winter, While Others Lose Them?

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Peter J. Grubb

2014-10-01

Full Text Available In subtropical montane semi-moist forest in SW China (SMSF, a large majority of evergreen tree and tall shrub species was found to have only one cohort of old leaves in early spring. In contrast, almost all species of evergreen tree and tall shrub in warm temperate rain forest (WTRF in Japan and sclerophylls in Mediterranean-climate forest (MSF of the Mediterranean Basin have two or more cohorts of old leaves in early spring; they drop their oldest cohort during or soon after leaf outgrowth in spring. Japanese WTRF has no dry season and MSF a dry summer. SMSF has a dry winter. On four evergreen Rhododendron species from SW China with only one cohort of old leaves in spring when in cultivation in Scotland, the majority of leaves in the senescing cohort fell by the end of December. We hypothesize that with dry winters, there is an advantage to dropping older leaves in autumn, because there is a low chance of appreciable positive assimilation in winter and a high chance of desiccation, reducing the resorption of dry mass and mineral nutrients from ageing leaves. Our hypothesis may be extended to cover evergreens at high altitude or high latitude that experience cold soils in winter.

Climatic potential for tourism in the Black Forest, Germany — winter season

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Endler, Christina; Matzarakis, Andreas

2011-05-01

Climate change, whether natural or human-caused, will have an impact on human life, including recreation and tourism among other things. In this study, methods from biometeorology and tourism climatology are used to assess the effect of a changed climate on tourism and recreation in particular. The study area is the Black Forest mountainous region of south-west Germany, which is well known for its tourist and recreational assets. Climate model projections for the 2021-2050 period based on REMO-UBA simulations with a high spatial resolution of 10 km are compared to a 30-year reference period (1971-2000) using the IPCC emission scenarios A1B and B1. The results show that the mean winter air temperature will increase by up to 1.8°C, which is the most pronounced warming compared to the other seasons. The annual precipitation amount will increase marginally by 5% in the A1B scenario and 10% in the B1 scenario. Winter precipitation contributes about 10% (A1B) and 30% (B1) to variations in annual precipitation. Although the results show that winter precipitation will increase slightly, snow days affecting skiing will be reduced on average by approximately 40% due to regional warming. Cold stress will be reduced on average by up to 25%. The result is that the thermal environment will be advanced, and warmer winters are likely to lead to an upward altitudinal shift of ski resorts and winter sport activities, thus displacing land-use currently dedicated to nature conservation.

Response of soil respiration to acid rain in forests of different maturity in southern China.

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Guohua Liang

Full Text Available The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF, a transitional mixed conifer and broadleaf forest (MF and an old-growth broadleaved forest (BF] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0. Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

Response of soil respiration to acid rain in forests of different maturity in southern China.

Science.gov (United States)

Liang, Guohua; Liu, Xingzhao; Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

2013-01-01

The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

Forest harvesting effects on soil temperature, moisture, and respiration in a bottomland hardwood forest

International Nuclear Information System (INIS)

Londo, A.J.; Messina, M.G.; Schoenholtz, S.H.

1999-01-01

The effect of forest disturbance on C cycling has become an issue, given concerns about escalating atmospheric C content. The authors examined the effects of harvest intensity on in situ and laboratory mineral soil respiration in an East Texas bottomland hardwood forest between 6 and 22 mo after harvesting. Treatments included a clearcut, a partial cut wherein approximately 58% of the basal area was removed, and an unharvested control. The soda-lime absorption technique was used for in situ respiration (CO 2 efflux) and the wet alkali method (NaOH) was used for laboratory mineral soil respiration. Soil temperature and moisture content were also measured. Harvesting significantly increased in situ respiration during most sampling periods. This effect was attributed to an increase in live root and microflora activity associated with postharvesting revegetation. In situ respiration increased exponentially (Q 10 relationship) as treatment soil temperatures increased, but followed a parabolic-type pattern through the range of soil moisture measured (mean range 10.4--31.5%). Mean rates of laboratory mineral soil respiration measured during the study were unaffected by cutting treatment for most sampling sessions. Overall, the mean rate of CO 2 efflux in the clearcuts was significantly higher than that in the partial cuts, which in turn was significantly higher than that in the controls. Mass balance estimates indicate that these treatment differences will have little or no long-term effect on C sequestration of these managed forests

Soil microbial diversity, site conditions, shelter forest land, saline water drip-irrigation, drift desert.

Science.gov (United States)

Jin, Zhengzhong; Lei, Jiaqiang; Li, Shengyu; Xu, Xinwen

2013-10-01

Soil microbes in forest land are crucial to soil development in extreme areas. In this study, methods of conventional culture, PLFA and PCR-DGGE were utilized to analyze soil microbial quantity, fatty acids and microbial DNA segments of soils subjected to different site conditions in the Tarim Desert Highway forest land. The main results were as follows: the soil microbial amount, diversity indexes of fatty acid and DNA segment differed significantly among sites with different conditions (F 84%), followed by actinomycetes and then fungi (<0.05%). Vertical differences in the soil microbial diversity were insignificant at 0-35 cm. Correlation analysis indicated that the forest trees grew better as the soil microbial diversity index increased. Therefore, construction of the Tarim Desert Highway shelter-forest promoted soil biological development; however, for enhancing sand control efficiency and promoting sand development, we should consider the effects of site condition in the construction and regeneration of shelter-forest ecological projects. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The partitioning of mercury in the solids components of forest soils and flooded forest soils in a hydroelectric reservoir, Quebec

International Nuclear Information System (INIS)

Dmytriw, R.P.

1993-11-01

Upon inundation, the soils in a hydroelection reservoir are subjected to several years of physical, biological and chemical changes as the transition from a terrestrial to an aquatic ecosystem is achieved. Changes in Eh, pH and microbial activity are believed to alter the metal binding capacity of solid substrates (organic matter, reactive Fe and Mn oxides, and clay minerals) within the soil profile, leading to remobilization of mercury associated with these phases. Four cores were collected along a transect from an unflooded forest soil to a pre-impoundment lake bottom sediment in the La-Grande-2 reservoir and watershed. The samples were sequentially extracted to determine the distribution of mercury between three operationally defined solid compartments: organic carbon, reactive Fe and Mn oxides/hydroxides, and the solid clay residue. Results indicate that up to 80% of the mercury in the O-horizon in forest soils and flooded forest soils, and up to 85% of the mercury in the lake sediments is bound to NaOH extractable organic carbon fractions. In the B-horizon podzol where organic content is low, 40-60% of the total mercury was found to be associated with reactive Fe minerals. In contrast, the flooded soil contains very little reactive Fe at any depth and the associated mercury concentrations are low. It is proposed that, upon inundation, oxide minerals are reduced and Hg released to the pore waters where it is immediately bound to an available substrate. Analyses of the residues suggests that there is an enrichment of mercury in the residual fraction immediately above the B-horizon of a flooded soil while the sulfide mineralization appears to play a role in sequestering mercury in lake sediments. 14 refs., 22 figs., 3 tabs

Feedback of global warming to soil carbon cycling in forest ecosystems

International Nuclear Information System (INIS)

Nakane, Kaneyuki

1993-01-01

Thus in this study the simulation of soil carbon cycling and dynamics of its storage in several types of mature forests developed from the cool-temperate to the tropics was carried out for quantitatively assessing carbon loss from the soil under several scenarios of global warming, based on the model of soil carbon cycling in forest ecosystems (Nakane et al. 1984, 1987 and Nakane 1992). (J.P.N.)

Soil quality standards and guidelines for forest sustainability in northwestern North America

Science.gov (United States)

Deborah Page-Dumroese; Martin Jurgensen; William Elliot; Thomas Rice; John Nesser; Thomas Collins; Robert. Meurisse

2000-01-01

Soil quality standards and guidelines of the USDA Forest Service were some of the first in the world to be developed to evaluate changes in forest soil productivity and sustainability after harvesting and site preparation. International and national development of criteria and indicators for maintenance of soil productivity make it imperative to have adequate threshold...

Coupling of microbial nitrogen transformations and climate in sclerophyll forest soils from the Mediterranean Region of central Chile.

Science.gov (United States)

Pérez, Cecilia A; Armesto, Juan J

2018-06-01

The Mediterranean region of central Chile is experiencing extensive "mega-droughts" with detrimental effects for the environment and economy of the region. In the northern hemisphere, nitrogen (N) limitation of Mediterranean ecosystems has been explained by the decoupling between N inputs and plant uptake during the dormant season. In central Chile, soils have often been considered N-rich in comparison to other Mediterranean ecosystems of the world, yet the impacts of expected intensification of seasonal drought remain unknown. In this work, we seek to disentangle patterns of microbial N transformations and their seasonal coupling with climate in the Chilean sclerophyll forest-type. We aim to assess how water limitation affects microbial N transformations, thus addressing the impact of ongoing regional climate trends on soil N status. We studied four stands of the sclerophyll forest-type in Chile. Field measurements in surface soils showed a 67% decline of free-living diazotrophic activity (DA) and 59% decrease of net N mineralization rates during the summer rainless and dormant season, accompanied by a stimulation of in-situ denitrification rates to values 70% higher than in wetter winter. Higher rates of both free-living DA and net N mineralization found during spring, provided evidence for strong coupling of these two processes during the growing season. Overall, the experimental addition of water in the field to litter samples almost doubled DA but had no effect on denitrification rates. We conclude that coupling of microbial mediated soil N transformations during the wetter growing season explains the N enrichment of sclerophyll forest soils. Expected increases in the length and intensity of the dry period, according to climate change models, reflected in the current mega-droughts may drastically reduce biological N fixation and net N mineralization, increasing at the same time denitrification rates, thereby potentially reducing long-term soil N capital

Soil Respiration Declines Following Beetle - Induced Forest Mortality in a Lodgepole Pine Forest

Science.gov (United States)

Borkhuu, B.; Peckham, S. D.; Norton, U.; Ewers, B. E.; Pendall, E.

2014-12-01

Lodgepole pine (Pinus contorta var. latifolia) forests in northern Colorado and southeast Wyoming have been undergoing a major mortality event owing to mountain pine beetle (Dendroctonus ponderosae) infestation since 2007. We studied biotic and abiotic drivers of growing season soil respiration in four mature stands experiencing different levels of mortality between 2008 and 2012 in the Medicine Bow Mountains, southeastern Wyoming, USA. For five years, beetle infestation significantly altered forest structure. Stand mortality was 30% and more than 80% in stands with the lowest and highest mortality, respectively. Understory vegetation cover increased by 50% for five years following beetle infestation. Needlefall was increased by more than 50% during first two years of beetle infestation compared to the pre-disturbance period. We did not observe an immediate increase in soil respiration following beetle infestation as suggested by some researchers. Soil respiration rates in midsummer ranged from 1.4 ± 0.1 μmol m-2 s-1 in stands with highest mortality to 3.1 ± 0.2 μmol m-2s-1 in uninfested stand. Live tree basal area was the dominant factor controlling soil respiration, explaining more than 60% of the interannual and spatial variations in response to the disturbance. In addition, soil respiration was significantly correlated with fine root biomass, which explained 55% of variations, providing strong evidence that autotrophic respiration dominated the forest soil respiration flux. Furthermore, the seasonality of soil respiration was controlled mainly by mean monthly precipitation and mid-day photosynthetically active radiation. Each factor predicted from 30% to 50% of seasonal soil respiration variability with the highest correlation coefficients in stand with the lowest mortality. Our results clearly indicate that the reduction of photosynthesis in trees over the infestation period significantly reduced soil respiration. The remaining activity in dead stands may

Assessing Bioenergy Harvest Risks: Geospatially Explicit Tools for Maintaining Soil Productivity in Western US Forests

Directory of Open Access Journals (Sweden)

Deborah Page-Dumroese

2011-09-01

Full Text Available Biomass harvesting for energy production and forest health can impact the soil resource by altering inherent chemical, physical and biological properties. These impacts raise concern about damaging sensitive forest soils, even with the prospect of maintaining vigorous forest growth through biomass harvesting operations. Current forest biomass harvesting research concurs that harvest impacts to the soil resource are region- and site-specific, although generalized knowledge from decades of research can be incorporated into management activities. Based upon the most current forest harvesting research, we compiled information on harvest activities that decrease, maintain or increase soil-site productivity. We then developed a soil chemical and physical property risk assessment within a geographic information system for a timber producing region within the Northern Rocky Mountain ecoregion. Digital soil and geology databases were used to construct geospatially explicit best management practices to maintain or enhance soil-site productivity. The proposed risk assessments could aid in identifying resilient soils for forest land managers considering biomass operations, policy makers contemplating expansion of biomass harvesting and investors deliberating where to locate bioenergy conversion facilities.

[Community traits of soil fauna in forestlands converted from cultivated lands in limestone red soil region of Ruichang, Jiangxi Province of China].

Science.gov (United States)

Li, Tao; Liu, Yuan-Qiug; Guo, Sheng-Mao; Ke, Guo-Qing; Zhang, Zhao; Xiao, Xu-Bao; Liu, Wu

2012-04-01

This paper studied the variations of the community composition and individuals' number of soil fauna in limestone red soil region of Ruichang, Jiangxi Province after six years of converting cultivated lands into forestlands. Three converted forestlands, including the lands of mixed multiple-species forest, bamboo-broadleaved forest, and tree-seedling integration, were selected as test objects, with cultivated lands as the comparison. A total of 34 orders, 17 classes, and 6 phyla of soil fauna were observed in the converted forestlands. The dominant group was Nematoda, accounting for 86.7% of the total, whereas Acarina, Enchytraeidae, and Collembola were the common groups. In the cultivated lands, soil fauna had 21 orders, 10 classes, and 5 phyla. The dominant group was also Nematoda, accounting 86.7% of the total, and Acarina and Enchytraeidae were the common groups. In the converted forestlands, the group number of rare species was greater than that in the cultivated lands (30 vs. 18), and, except in winter, the group number and average density were significantly higher than those in the cultivated lands (P soil fauna in the soil profiles showed an obvious surface accumulation, which was more apparent in converted forestlands than in cultivated lands, and the individuals' number had significant differences between the surface (0-5 cm) layer and the 5-10 cm and 10-15 cm layers (P soil fauna in the converted forestlands had a seasonal variation ranked in the order of summer > autumn > spring > winter, and there was a significant difference between summer-autumn and spring-winter. The average density of the soil fauna also had a seasonal variation but ranked as autumn > summer > spring > winter, and the differences among the seasons were significant (P soil fauna was significantly higher in converted forestlands than in cultivated lands, and was the highest in mixed multiple-species forestland and the least in tree-seedling integration land.

Boreal coniferous forest density leads to significant variations in soil physical and geochemical properties

Science.gov (United States)

Bastianelli, Carole; Ali, Adam A.; Beguin, Julien; Bergeron, Yves; Grondin, Pierre; Hély, Christelle; Paré, David

2017-07-01

At the northernmost extent of the managed forest in Quebec, Canada, the boreal forest is currently undergoing an ecological transition between two forest ecosystems. Open lichen woodlands (LW) are spreading southward at the expense of more productive closed-canopy black spruce-moss forests (MF). The objective of this study was to investigate whether soil properties could distinguish MF from LW in the transition zone where both ecosystem types coexist. This study brings out clear evidence that differences in vegetation cover can lead to significant variations in soil physical and geochemical properties.Here, we showed that soil carbon, exchangeable cations, and iron and aluminium crystallinity vary between boreal closed-canopy forests and open lichen woodlands, likely attributed to variations in soil microclimatic conditions. All the soils studied were typical podzolic soil profiles evolved from glacial till deposits that shared a similar texture of the C layer. However, soil humus and the B layer varied in thickness and chemistry between the two forest ecosystems at the pedon scale. Multivariate analyses of variance were used to evaluate how soil properties could help distinguish the two types at the site scale. MF humus (FH horizons horizons composing the O layer) showed significantly higher concentrations of organic carbon and nitrogen and of the main exchangeable base cations (Ca, Mg) than LW soils. The B horizon of LW sites held higher concentrations of total Al and Fe oxides and particularly greater concentrations of inorganic amorphous Fe oxides than MF mineral soils, while showing a thinner B layer. Overall, our results show that MF store three times more organic carbon in their soils (B+FH horizons, roots apart) than LW. We suggest that variations in soil properties between MF and LW are linked to a cascade of events involving the impacts of natural disturbances such as wildfires on forest regeneration that determines the vegetation structure (stand density

Short-term effects of forest disturbances on soil nematode communities in European mountain spruce forests.

Science.gov (United States)

Čerevková, A; Renčo, M; Cagáň, L

2013-09-01

The nematode communities in spruce forests were compared with the short-term effects of forest damage, caused by windstorm, wildfire and management practices of forest soils. Soil samples were collected in June and October from 2006 to 2008 in four different sites: (1) forest unaffected by the wind (REF); (2) storm-felled forest with salvaged timber (EXT); (3) modified forest affected by timber salvage (wood removal) and forest fire (FIR); and (4) storm-felled forest where timber had been left unsalvaged (NEX). Nematode analysis showed that the dominant species in all four investigated sites were Acrobeloides nanus and Eudorylaimus silvaticus. An increase of A. nanus (35% of the total nematode abundance) in the first year in the FIR site led to the highest total abundance of nematodes compared with other sites, where nematode abundance reached the same level in the third year. In the FIR site bacterial feeders appeared to be the most representative trophic group, although in the second and third year, after disturbance, the abundance of this trophic group gradually decreased. In the NEX site, the number of nematode species, population densities and Maturity Index were similar to that recorded for the FIR site. In EXT and NEX sites, the other dominant species was the plant parasitic nematode Paratylenchus microdorus. Analyses of nematodes extracted from different forest soil samples showed that the highest number of species and diversity index for species (H'spp) were in the REF site. Differences between the nematode fauna in REF and other localities were clearly depicted by cluster analysis. The greatest Structure Index and Enrichment Index values were also in REF. In the EXT site, the number of nematode species, their abundance, H'spp and Maturity Index were not significantly different from those recorded in the reference site.

Magnetic minerals in soils across the forest-prairie ecotone in NW Minnesota

Science.gov (United States)

Maxbauer, D.; Feinberg, J. M.; Fox, D. L.; Nater, E. A.

2016-12-01

Soil pedogenesis results in a complex assemblage of iron oxide minerals that can be disentangled successfully using sensitive magnetic techniques to better delineate specific soil processes. Here, we evaluate the variability in soil processes within forest, prairie, and transitional soils along an 11 km transect of anthropogenically unaltered soils that span the forest-to-prairie ecotone in NW Minnesota. All soils in this study developed on relatively uniform topography, similar glacial till parent material, under a uniform climate, and presumably over similar time intervals. The forest-to-prairie transition zone in this region is controlled by naturally occurring fires, affording the opportunity to evaluate differences in soil processes related to vegetation (forest versus prairie) and burning (prairie and transitional soils). Results suggest that the pedeogenic fraction of magnetite/maghemite in soils is similar in all specimens and is independent of soil type, vegetation, and any effects of burning. Magnetically enhanced horizons have 45% of remanence held by a low-coercivity pedogenic component (likely magnetite/maghemite) regardless of vegetation cover and soil type. Enhancement ratios for magnetic susceptibility and low-field remanences, often used as indicators of pedogenic magnetic minerals, are more variable but remain statistically equivalent across the transect. These results support the hypothesis that pedogenic magnetic minerals in soils mostly reflect ambient climatic conditions regardless of the variability in soil processes related to vegetation and soil type. The non-pedogenic magnetic mineral assemblage shows clear distinctions between the forest, prairie, and transitional soils in hysteresis properties (remanence and coercivity ratios; Mr/Ms and Bc/Bcr, respectively), suggesting that variable processes in these settings influence the local magnetic mineral assemblage, and that it may be possible to use magnetic minerals in paleosols to constrain

Comparison of seasonal soil microbial process in snow-covered temperate ecosystems of northern China.

Directory of Open Access Journals (Sweden)

Xinyue Zhang

Full Text Available More than half of the earth's terrestrial surface currently experiences seasonal snow cover and soil frost. Winter compositional and functional investigations in soil microbial community are frequently conducted in alpine tundra and boreal forest ecosystems. However, little information on winter microbial biogeochemistry is known from seasonally snow-covered temperate ecosystems. As decomposer microbes may differ in their ability/strategy to efficiently use soil organic carbon (SOC within different phases of the year, understanding seasonal microbial process will increase our knowledge of biogeochemical cycling from the aspect of decomposition rates and corresponding nutrient dynamics. In this study, we measured soil microbial biomass, community composition and potential SOC mineralization rates in winter and summer, from six temperate ecosystems in northern China. Our results showed a clear pattern of increased microbial biomass C to nitrogen (N ratio in most winter soils. Concurrently, a shift in soil microbial community composition occurred with higher fungal to bacterial biomass ratio and gram negative (G- to gram positive (G+ bacterial biomass ratio in winter than in summer. Furthermore, potential SOC mineralization rate was higher in winter than in summer. Our study demonstrated a distinct transition of microbial community structure and function from winter to summer in temperate snow-covered ecosystems. Microbial N immobilization in winter may not be the major contributor for plant growth in the following spring.

Prediction of Soil Erosion Rates in Japan where Heavily Forested Landscape with Unstable Terrain

Science.gov (United States)

Nanko, K.; Oguro, M.; Miura, S.; Masaki, T.

2016-12-01

Soil is fundamental for plant growth, water conservation, and sustainable forest management. Multidisciplinary interest in the role of the soil in areas such as biodiversity, ecosystem services, land degradation, and water security has been growing (Miura et al., 2015). Forest is usually protective land use from soil erosion because vegetation buffers rainfall power and erosivity. However, some types of forest in Japan show high susceptibility to soil erosion due to little ground cover and steep slopes exceeding thirty degree, especially young Japanese cypress (Chamaecyparis obtusa) plantations (Miura et al., 2002). This is a critical issue for sustainable forest management because C. obtusaplantations account for 10% of the total forest coverage in Japan (Forestry Agency, 2009). Prediction of soil erosion rates on nationwide scale is necessary to make decision for future forest management plan. To predict and map soil erosion rates across Japan, we applied three soil erosion models, RUSLE (Revised Universal Soil Loss Equation, Wischmeier and Smith, 1978), PESERA (Pan-European Soil Erosion Risk Assessment, Kirkby et al., 2003), and RMMF (Revised Morgan-Morgan-Finney, Morgan, 2001). The grid scale is 1-km. RUSLE and PESERA are most widely used erosion models today. RMMF includes interactions between rainfall and vegetation, such as canopy interception and ratio of canopy drainage in throughfall. Evaporated rainwater by canopy interception, generally accounts for 15-20% in annual rainfall, does not contribute soil erosion. Whereas, larger raindrops generated by canopy drainage produced higher splash erosion rates than gross rainfall (Nanko et al., 2008). Therefore, rainfall redistribution process in canopy should be considered to predict soil erosion rates in forested landscape. We compared the results from three erosion models and analyze the importance of environmental factors for the prediction of soil erosion rates. This research was supported by the Environment

Boreal coniferous forest density leads to significant variations in soil physical and geochemical properties

Directory of Open Access Journals (Sweden)

C. Bastianelli

2017-07-01

Full Text Available At the northernmost extent of the managed forest in Quebec, Canada, the boreal forest is currently undergoing an ecological transition between two forest ecosystems. Open lichen woodlands (LW are spreading southward at the expense of more productive closed-canopy black spruce–moss forests (MF. The objective of this study was to investigate whether soil properties could distinguish MF from LW in the transition zone where both ecosystem types coexist. This study brings out clear evidence that differences in vegetation cover can lead to significant variations in soil physical and geochemical properties.Here, we showed that soil carbon, exchangeable cations, and iron and aluminium crystallinity vary between boreal closed-canopy forests and open lichen woodlands, likely attributed to variations in soil microclimatic conditions. All the soils studied were typical podzolic soil profiles evolved from glacial till deposits that shared a similar texture of the C layer. However, soil humus and the B layer varied in thickness and chemistry between the two forest ecosystems at the pedon scale. Multivariate analyses of variance were used to evaluate how soil properties could help distinguish the two types at the site scale. MF humus (FH horizons horizons composing the O layer showed significantly higher concentrations of organic carbon and nitrogen and of the main exchangeable base cations (Ca, Mg than LW soils. The B horizon of LW sites held higher concentrations of total Al and Fe oxides and particularly greater concentrations of inorganic amorphous Fe oxides than MF mineral soils, while showing a thinner B layer. Overall, our results show that MF store three times more organic carbon in their soils (B+FH horizons, roots apart than LW. We suggest that variations in soil properties between MF and LW are linked to a cascade of events involving the impacts of natural disturbances such as wildfires on forest regeneration that determines the vegetation

Indicators of soil quality in the implantation of no-till system with winter crops.

OpenAIRE

NOGUEIRA, M. A.; TELLES, T. S.; FAGOTTI, D. dos S. L.; BRITO, O. R.; PRETE, C. E. C.; GUIMARÃES, M. de F.

2014-01-01

We assessed the effect of different winter crops on indicators of soil quality related to C and N cycling and C fractions in a Rhodic Kandiudult under no-till system at implantation, during two growing seasons, in Londrina PR Brazil. The experimental design was randomized blocks with split-plot in time arrangement, with four replications. The parcels were the winter crops: multicropping of cover crops with black oat (Avena strigosa), hairy vetch (Vicia villosa) and fodder radish (Raphanus sat...

Moss-nitrogen input to boreal forest soils

DEFF Research Database (Denmark)

Rousk, Kathrin; Jones, Davey; DeLuca, Thomas

2014-01-01

Cyanobacteria living epiphytically on mosses in pristine, unpolluted areas fix substantial amounts of atmospheric nitrogen (N) and therefore represent a primary source of N in N-limited boreal forests. However, the fate of this N is unclear, in particular, how the fixed N2 enters the soil and bec...... and that transfer of N to the soil is not facilitated by fungal hyphae....

A novel technique using the Hendrickx centrifuge for extracting winter sporangia of Synchytrium endobioticum from soil

NARCIS (Netherlands)

Wander, J.G.N.; Berg, van den W.; Boogert, van den P.H.J.F.; Lamers, J.G.; Leeuwen, van G.C.M.; Hendrickx, G.; Bonants, P.J.M.

2007-01-01

A zonal centrifugation method, known as the Hendrickx centrifuge technique, was tested for routine detection of winter sporangia of Synchytrium endobioticum in soil. In four experiments the ability of the Hendrickx centrifuge to extract the sporangia from soil was compared with a method used by the

Nitrate Leaching from Winter Cereal Cover Crops Using Undisturbed Soil-Column Lysimeters.

Science.gov (United States)

Meisinger, John J; Ricigliano, Kristin A

2017-05-01

Cover crops are important management practices for reducing nitrogen (N) leaching, especially in the Chesapeake Bay watershed, which is under total maximum daily load (TMDL) restraints. Winter cereals are common cool-season crops in the Bay watershed, but studies have not directly compared nitrate-N (NO-N) leaching losses from these species. A 3-yr cover crop lysimeter study was conducted in Beltsville, MD, to directly compare NO-N leaching from a commonly grown cultivar of barley ( L.), rye ( L.), and wheat ( L.), along with a no-cover control, using eight tension-drained undisturbed soil column lysimeters in a completely randomized design with two replicates. The lysimeters were configured to exclude runoff and to estimate NO-N leaching and flow-weighted NO-N concentration (FWNC). The temporal pattern of NO-N leaching showed a consistent highly significant ( leaching with cover crops compared with no cover but showed only small and periodically significant ( leaching was more affected by the quantity of establishment-season (mid-October to mid-December) precipitation than by cover crop species. For example, compared with no cover, winter cereal covers reduced NO-N leaching 95% in a dry year and 50% in wet years, with corresponding reductions in FWNC of 92 and 43%, respectively. These results are important for scientists, nutrient managers, and policymakers because they directly compare NO-N leaching from winter cereal covers and expand knowledge for developing management practices for winter cereals that can improve water quality and increase N efficiency in cropping systems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Preliminary assessment of soil erosion impact during forest restoration process

Science.gov (United States)

Lai, Yen-Jen; Chang, Cheng-Sheng; Tsao, Tsung-Ming; Wey, Tsong-Huei; Chiang, Po-Neng; Wang, Ya-Nan

2014-05-01

Taiwan has a fragile geology and steep terrain. The 921 earthquake, Typhoon Toraji, Typhoon Morakot, and the exploitation and use of the woodland by local residents have severely damaged the landscape and posed more severe challenges to the montane ecosystem. A land conservation project has been implemented by the Experimental Forest of National Taiwan University which reclaimed approximately 1,500 hectares of leased woodland from 2008 to 2010, primarily used to grow bamboo, tea trees, betel nut, fruit, and vegetable and about 1,298 hectares have been reforested. The process of forest restoration involves clear cutting, soil preparation and a six-year weeding and tending period which may affect the amount of soil erosion dramatically. This study tried to assess the impact of forest restoration from the perspective of soil erosion through leased-land recovery periods and would like to benefit the practical implementation of reforestation in the future. A new plantation reforested in the early 2013 and a nearby 29-year-old mature forest were chosen as experimental and comparison sites. A self-designed weir was set up in a small watershed of each site for the runoff and sediment yield observation. According to the observed results from May to August 2013, a raining season in Taiwan, the runoff and erosion would not as high as we expected, because the in-situ soil texture of both sites is sandy loam to sandy with high percentage of coarse fragment which increased the infiltration. There were around 200 kg to 250 kg of wet sand/soil yielded in mature forest during the hit of Typhoon Soulik while the rest of the time only suspended material be yielded at both sites. To further investigate the influence of the six-year weeding and tending period, long term observations are needed for a more completed assessment of soil erosion impact.

The impact of clearcutting in boreal forests of Russia on soils: A review

Science.gov (United States)

Dymov, A. A.

2017-07-01

Data on the impact of tree logging in boreal forests of Russia on soils are systematized. Patterns of soil disturbances and transformation of microclimatic parameters within clearcutting areas are discussed. Changes in the conditions of pedogenesis in secondary forests are analyzed. It is suggested that the changes in forest soils upon reforestation of clearcutting areas might be considered as specific post-logging soil successions. Data characterizing changes in the thickness of litter horizons and in the intensity of elementary pedogenic processes, acidity, and the content of exchangeable bases in soils of clearcutting areas in the course of their natural reforestation are considered. The examples of human-disturbed (turbated) soil horizons and newly formed anthropogenic soils on clearcutting areas are described. It is suggested that the soils on mechanically disturbed parts of clearcutting areas can be separated as a specific group of detritus turbozems.

137Cs in the fungal compartment of Swedish forest soils

International Nuclear Information System (INIS)

Vinichuk, Mykhaylo M.; Johanson, Karl J.; Taylor, Andy F.S.

2004-01-01

The 137 Cs activities in soil profiles and in the mycelia of four ectomycorrhizal fungi were studied in a Swedish forest in an attempt to understand the mechanisms governing the transfer and retention of 137 Cs in forest soil. The biomass of four species of fungi was determined and estimated to be 16 g m -2 in a peat soil and 47-189 g m -2 in non-peat soil to the depth of 10 cm. The vertical distribution was rather homogeneous for two species (Tylospora spp. and Piloderma fallax) and very superficial for Hydnellum peckii. Most of the 137 Cs activity in mycelium of non-peat soils was found in the upper 5 cm. Transfer factors were quite high even for those species producing resupinate sporocarps. In the peat soil only approximately 0.3% of the total 137 Cs inventory in soil was found in the fungal mycelium. The corresponding values for non-peat soil were 1.3, 1.8 and 1.9%

Biological properties of soils of former forest fires in Samosir Regency of North Sumatera

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D. Elfiati

2016-04-01

Full Text Available A study that was aimed to identify the impact of forest fires on the biological properties of soils was carried out at former forest fire areas in Samosir Regency of North Sumatera. Soil samples were collected from former forest fire areas of 2014, 2013, 2012, 2011, 2010. The composite soil samples were collected systematically using diagonal method as much as 5 points in each period of fire. The soil samples were taken at three plots measuring 20 x 20 m 0-20 cm depth. Soil biological properties observed were soil organic C content, total number of microbes, abundance of arbuscular mycorrhizal fungi, phosphate solubilizing microbes, and soil microbial activity. The results showed that organic C content ranged from 0.75 to 2.47% which included criteria for very low to moderate. Arbuscular mycorrhizal fungi spores were found belonging to the genus of Glomus and Acaulospora. Spore number increased with the fire period ranging from 45 spores (forest fire in 2014 to 152 spores (forest fire in 2010. The total number of microbes obtained ranged from 53.78 x 107 cfu/mL (forest fire in 2010 to 89.70 x107 cfu/mL (forest fire in 2013. It was found 29 isolates of phosphate solubilizing microbes that consisted of 14 bacterial isolates and 15 fungi isolates with densities ranging from 27.642 x105 cfu/mL (forest fires in 2014 to 97.776 x 105 cfu/ mL (forest fires in 2011. The isolates of phosphate solubilizing bacteria identified consisted of Pseudomonas, Flavobacterium, Staphylococcus, and Mycobacterium genus, whereas the isolates of phosphate solubilizing fungi obtained consisted of Aspergillus and Penicillium genus. Soil respiration ranged from 2.14 kg / day (forest fire in 2010 up to 3.71 kg / day (forest fire in 2013. The varied results were greatly influenced by the type or form of the fires and intensity of fires. In the study area the type or form of the fires were canopy fires with low intensity.

Urbanization in China drives soil acidification of Pinus massoniana forests

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Huang, Juan; Zhang, Wei; Mo, Jiangming; Wang, Shizhong; Liu, Juxiu; Chen, Hao

2015-09-01

Soil acidification instead of alkalization has become a new environmental issue caused by urbanization. However, it remains unclear the characters and main contributors of this acidification. We investigated the effects of an urbanization gradient on soil acidity of Pinus massoniana forests in Pearl River Delta, South China. The soil pH of pine forests at 20-cm depth had significantly positive linear correlations with the distance from the urban core of Guangzhou. Soil pH reduced by 0.44 unit at the 0-10 cm layer in urbanized areas compared to that in non-urbanized areas. Nitrogen deposition, mean annual temperature and mean annual precipitation were key factors influencing soil acidification based on a principal component analysis. Nitrogen deposition showed significant linear relationships with soil pH at the 0-10 cm (for ammonium N (-N), P greatly contributed to a significant soil acidification occurred in the urbanized environment.

Divergence of dominant factors in soil microbial communities and functions in forest ecosystems along a climatic gradient

Science.gov (United States)

Xu, Zhiwei; Yu, Guirui; Zhang, Xinyu; He, Nianpeng; Wang, Qiufeng; Wang, Shengzhong; Xu, Xiaofeng; Wang, Ruili; Zhao, Ning

2018-03-01

Soil microorganisms play an important role in regulating nutrient cycling in terrestrial ecosystems. Most of the studies conducted thus far have been confined to a single forest biome or have focused on one or two controlling factors, and few have dealt with the integrated effects of climate, vegetation, and soil substrate availability on soil microbial communities and functions among different forests. In this study, we used phospholipid-derived fatty acid (PLFA) analysis to investigate soil microbial community structure and extracellular enzymatic activities to evaluate the functional potential of soil microbes of different types of forests in three different climatic zones along the north-south transect in eastern China (NSTEC). Both climate and forest type had significant effects on soil enzyme activities and microbial communities with considerable interactive effects. Except for soil acid phosphatase (AP), the other three enzyme activities were much higher in the warm temperate zone than in the temperate and the subtropical climate zones. The soil total PLFAs and bacteria were much higher in the temperate zone than in the warm temperate and the subtropical zones. The soil β-glucosidase (BG) and N-acetylglucosaminidase (NAG) activities were highest in the coniferous forest. Except for the soil fungi and fungi-bacteria (F/B), the different groups of microbial PLFAs were much higher in the conifer broad-leaved mixed forests than in the coniferous forests and the broad-leaved forests. In general, soil enzyme activities and microbial PLFAs were higher in primary forests than in secondary forests in temperate and warm temperate regions. In the subtropical region, soil enzyme activities were lower in the primary forests than in the secondary forests and microbial PLFAs did not differ significantly between primary and secondary forests. Different compositions of the tree species may cause variations in soil microbial communities and enzyme activities. Our results

Sample sizes to control error estimates in determining soil bulk density in California forest soils

Science.gov (United States)

Youzhi Han; Jianwei Zhang; Kim G. Mattson; Weidong Zhang; Thomas A. Weber

2016-01-01

Characterizing forest soil properties with high variability is challenging, sometimes requiring large numbers of soil samples. Soil bulk density is a standard variable needed along with element concentrations to calculate nutrient pools. This study aimed to determine the optimal sample size, the number of observation (n), for predicting the soil bulk density with a...

Soil Organic Matter Stabilization via Mineral Interactions in Forest Soils with Varying Saturation Frequency

Science.gov (United States)

Possinger, A. R.; Inagaki, T.; Bailey, S. W.; Kogel-Knabner, I.; Lehmann, J.

2017-12-01

Soil carbon (C) interaction with minerals and metals through surface adsorption and co-precipitation processes is important for soil organic C (SOC) stabilization. Co-precipitation (i.e., the incorporation of C as an "impurity" in metal precipitates as they form) may increase the potential quantity of mineral-associated C per unit mineral surface compared to surface adsorption: a potentially important and as yet unaccounted for mechanism of C stabilization in soil. However, chemical, physical, and biological characterization of co-precipitated SOM as such in natural soils is limited, and the relative persistence of co-precipitated C is unknown, particularly under dynamic environmental conditions. To better understand the relationships between SOM stabilization via organometallic co-precipitation and environmental variables, this study compares mineral-SOM characteristics across a forest soil (Spodosol) hydrological gradient with expected differences in co-precipitation of SOM with iron (Fe) and aluminum (Al) due to variable saturation frequency. Soils were collected from a steep, well-drained forest soil transect with low, medium, and high frequency of water table intrusion into surface soils (Hubbard Brook Experimental Forest, Woodstock, NH). Lower saturation frequency soils generally had higher C content, C/Fe, C/Al, and other indicators of co-precipitation interactions resulting from SOM complexation, transport, and precipitation, an important process of Spodosol formation. Preliminary Fe X-ray Absorption Spectroscopic (XAS) characterization of SOM and metal chemistry in low frequency profiles suggest co-precipitation of SOM in the fine fraction (soils showed greater SOC mineralization per unit soil C for low saturation frequency (i.e., higher co-precipitation) soils; however, increased mineralization may be attributed to non-mineral associated fractions of SOM. Further work to identify the component of SOM contributing to rapid mineralization using 13C

Assessing soil quality: practicable standards for sustainable forest productivity in the United States

Science.gov (United States)

Robert F. Powers; Allan E. Tiarks; James R. Boyle

1998-01-01

Productive soils form the foundation for productive forests. But unfortunately, the significance of soil seems lost to modem society. Most of us are too far removed from the natural factors of production to appreciate the multiple roles of soil. Nor is its worth recognized well by many forest managers who too often see soil only in its capacity for logging roads and...

Soil carbon and soil physical properties response to incorporating mulched forest slash

Science.gov (United States)

Felipe G. Sanchez; Emily A. Carter; John. F. Klepac

2000-01-01

A study was installed in the Lower Coastal Plain near Washington, NC, to test the hypothesis that incorporating organic matter in the form of comminuted forest slash would increase soil carbon and nutrient pools, and alter soil physical properties to favor pine growth. Two sites were selected, an organic and a mineral site, to compare the treatment effects on...

Urbanization Effects on the Vertical Distribution of Soil Microbial Communities and Soil C Storage across Edge-to-Interior Urban Forest Gradients

Science.gov (United States)

Rosier, C. L.; Van Stan, J. T., II; Trammell, T. L.

2017-12-01

Urbanization alters environmental conditions such as temperature, moisture, carbon (C) and nitrogen (N) deposition affecting critical soil processes (e.g., C storage). Urban soils experience elevated N deposition (e.g., transportation, industry) and decreased soil moisture via urban heat island that can subsequently alter soil microbial community structure and activity. However, there is a critical gap in understanding how increased temperatures and pollutant deposition influences soil microbial community structure and soil C/N cycling in urban forests. Furthermore, canopy structural differences between individual tree species is a potentially important mechanism facilitating the deposition of pollutants to the soil. The overarching goal of this study is to investigate the influence of urbanization and tree species structural differences on the bacterial and fungal community and C and N content of soils experiencing a gradient of urbanization pressures (i.e., forest edge to interior; 150-m). Soil cores (1-m depth) were collected near the stem (urban pressure (i.e., forest edge). We further expect trees located on the edge of forest fragments will maintain greater surface soil (urbanization alters soil microbial community composition via reduced soil moisture and carbon storage potential via deposition gradients. Further analyses will answer important questions regarding how individual tree species alters urban soil C storage, N retention, and microbial dynamics.

The relation between forest structure and soil burn severity

Science.gov (United States)

Theresa B. Jain; Russell T. Graham; David S. Pilliod

2006-01-01

A study funded through National Fire Plan evaluates the relation between pre-wildfire forest structure and post-wildfire soil burn severity across three forest types: dry, moist, and cold forests. Over 73 wildfires were sampled in Idaho, Oregon, Montana, Colorado, and Utah, which burned between 2000 and 2003. Because of the study’s breadth, the results are applicable...

Clay minerals, metallic oxides and oxy-hydroxides and soil organic carbon distribution within soil aggregates in temperate forest soils

Science.gov (United States)

Gartzia-Bengoetxea, Nahia; Fernández-Ugalde, Oihane; Virto, Iñigo; Arias-González, Ander

2017-04-01

Soil mineralogy is of primary importance for key environmental services provided by soils like carbon sequestration. However, current knowledge on the effects of clay mineralogy on soil organic carbon (SOC) stabilization is based on limited and conflicting data. In this study, we investigated the relationship between clay minerals, metallic oxides and oxy-hydroxides and SOC distribution within soil aggregates in mature Pinus radiata D.Don forest plantations. Nine forest stands located in the same geographical area of the Basque Country (North of Spain) were selected. These stands were planted on different parent material (3 on each of the following: sandstone, basalt and trachyte). There were no significant differences in climate and forest management among them. Moreover, soils under these plantations presented similar content of clay particles. We determined bulk SOC storage, clay mineralogy, the content of Fe-Si-Al-oxides and oxyhydroxides and the distribution of organic C in different soil aggregate sizes at different soil depths (0-5 cm and 5-20 cm). The relationship between SOC and abiotic factors was investigated using a factor analysis (PCA) followed by stepwise regression analysis. Soils developed on sandstone showed significantly lower concentration of SOC (29 g C kg-1) than soils developed on basalts (97 g C kg-1) and trachytes (119 g C kg-1). The soils on sandstone presented a mixed clay mineralogy dominated by illite, with lesser amounts of hydroxivermiculite, hydrobiotite and kaolinite, and a total absence of interstratified chlorite/vermiculite. In contrast, the major crystalline clay mineral identified in the soils developed on volcanic rocks was interstratified chlorite/vermiculite. Nevertheless, no major differences were observed between basaltic and trachytic soils in the clay mineralogy. The selective extraction of Fe showed that the oxalate extractable iron was significantly lower in soils on sandstone (3.7%) than on basalts (11.2%) and

Soil-leaf transfer of chemical elements for the Atlantic Forest

International Nuclear Information System (INIS)

Joacir De Franca, E.; De Nadai Fernandes, E.A.; Bacchi, M.A.; Tagliaferro, F.S.

2007-01-01

Soil analysis could improve environmental studies since soil is the main source of chemical elements for plants. In this study, soil samples collected at 0-10 cm depth under tree crown projection were analyzed by INAA. Using the chemical composition of the leaf previously determined, the leaf-soil transfer factors of chemical elements could be estimated for the Atlantic Forest. Despite the variability of the intra-species, the transfer factors were specific for some plant species due to their element accumulation in the leaves. Similar Br-Zn combined transfer factors were obtained for the species grouped according to habitats in relation to their position (understory or dominant species) in the forest canopy. (author)

Algological and Mycological Characterization of Soils under Pine and Birch Forests in the Pasvik Reserve

Science.gov (United States)

Korneikova, M. V.; Redkina, V. V.; Shalygina, R. R.

2018-02-01

The structure of algological and mycological complexes in Al-Fe-humus podzols (Albic Podzols) under pine and birch forests of the Pasvik Reserve is characterized. The number of micromycetes is higher in more acid soils of the pine forest, while the species diversity is greater under the birch forest. The genus Penicillium includes the largest number of species. The greatest abundance and occurrence frequency are typical for Penicillium spinulosum, P. glabrum, and Trichoderma viride in pine forest and for Umbelopsis isabellina, Mucor sp., Mortierella alpina, P. glabrum, Aspergillus ustus, Trichoderma viride, and T. koningii in birch forest. Cyanobacteria-algal cenoses of the investigated soils are predominated by green algae. Soils under birch forest are distinguished by a greater diversity of algal groups due to the presence of diatoms and xanthophytes. Species of frequent occurrence are represented by Pseudococcomyxa simplex and Parietochloris alveolaris in soils of the pine forest and by Tetracystis cf. aplanospora, Halochlorella rubescens, Pseudococcomyxa simplex, Fottea stichococcoides, Klebsormidium flaccidum, Hantzschia amphioxys, Microcoleus vaginatus, and Aphanocapsa sp. in soils under birch forest

Soil solution and extractable soil nitrogen response to climate change in two boreal forest ecosystems

NARCIS (Netherlands)

Verburg, P.H.

2005-01-01

Several studies show that increases in soil temperature result in higher N mineralization rates in soils. It is, however, unclear if additional N is taken up by the vegetation or accumulates in the soil. To address this question two small, forested catchments in southern Norway were experimentally

Soil charcoal as long-term pyrogenic carbon storage in Amazonian seasonal forests.

Science.gov (United States)

Turcios, Maryory M; Jaramillo, Margarita M A; do Vale, José F; Fearnside, Philip M; Barbosa, Reinaldo Imbrozio

2016-01-01

Forest fires (paleo + modern) have caused charcoal particles to accumulate in the soil vertical profile in Amazonia. This forest compartment is a long-term carbon reservoir with an important role in global carbon balance. Estimates of stocks remain uncertain in forests that have not been altered by deforestation but that have been impacted by understory fires and selective logging. We estimated the stock of pyrogenic carbon derived from charcoal accumulated in the soil profile of seasonal forest fragments impacted by fire and selective logging in the northern portion of Brazilian Amazonia. Sixty-nine soil cores to 1-m depth were collected in 12 forest fragments of different sizes. Charcoal stocks averaged 3.45 ± 2.17 Mg ha(-1) (2.24 ± 1.41 Mg C ha(-1) ). Pyrogenic carbon was not directly related to the size of the forest fragments. This carbon is equivalent to 1.40% (0.25% to 4.04%) of the carbon stocked in aboveground live tree biomass in these fragments. The vertical distribution of pyrogenic carbon indicates an exponential model, where the 0-30 cm depth range has 60% of the total stored. The total area of Brazil's Amazonian seasonal forests and ecotones not altered by deforestation implies 65-286 Tg of pyrogenic carbon accumulated along the soil vertical profile. This is 1.2-2.3 times the total amount of residual pyrogenic carbon formed by biomass burning worldwide in 1 year. Our analysis suggests that the accumulated charcoal in the soil vertical profile in Amazonian forests is a substantial pyrogenic carbon pool that needs to be considered in global carbon models. © 2015 John Wiley & Sons Ltd.

Methods of soil resampling to monitor changes in the chemical concentrations of forest soils

Science.gov (United States)

Gregory B. Lawrence; Ivan J. Fernandez; Paul W. Hazlett; Scott W. Bailey; Donald S. Ross; Thomas R. Villars; Angelica Quintana; Rock Ouimet; Michael R. McHale; Chris E. Johnson; Russell D. Briggs; Robert A. Colter; Jason Siemion; Olivia L. Bartlett; Olga Vargas; Michael R. Antidormi; Mary M. Koppers

2016-01-01

Recent soils research has shown that important chemical soil characteristics can change in less than a decade, often the result of broad environmental changes. Repeated sampling to monitor these changes in forest soils is a relatively new practice that is not well documented in the literature and has only recently been broadly embraced by the scientific community. The...

Experimental soil warming effects on C, N, and major element cycling in a low elevation spruce-fir forest soil

Science.gov (United States)

Lindsey E. Rustad; Ivan J. Fernandez; Stephanie Arnold

1996-01-01

The effect of global warming on north temperate and boreal forest soils has been the subject of much recent debate. These soils serve as major reservoirs for C, N, and other nutrients necessary for forest growth and productivity. Given the uncertainties in estimates of organic matter turnover rates and storage, it is unclear whether these soils will serve as short or...

Temporal and spatial variation of nitrogen transformations in a coniferous forest soils.

NARCIS (Netherlands)

Laverman, A.M.; Zoomer, H.R.; van Verseveld, H.W.; Verhoef, H.A.

2000-01-01

Forest soils show a great degree of temporal and spatial variation of nitrogen mineralization. The aim of the present study was to explain temporal variation in nitrate leaching from a nitrogen-saturated coniferous forest soil by potential nitrification, mineralization rates and nitrate uptake by

Effect of Simulated N Deposition on Soil Exchangeable Cations in Three Forest Types of Subtropical China

Institute of Scientific and Technical Information of China (English)

LU Xian-Kai; MO Jiang-Ming; P.GUNDERSERN; ZHU Wei-Xing; ZHOU Guo-Yi; LI De-Jun; ZHANG Xu

2009-01-01

The effects of simulated nitrogen (N) deposition on soil exchangeable cations were studied in three forest types of subtropical China.Four N treatments with three replications were designed for the monsoon evergreen broadleaf forest (mature forest):control (0 kg N ha-1 year-1),low N (50 kg N ha-1 year-1),medium N (100 kg N ha-1 year-1) and high N (150 kg N ha-1 ycar-1),and only three treatments (i.e.,control,low N,medium N) were established for the pine and mixed forests.Nitrogen had been applied continuously for 26 months before the measurement.The mature forest responded more rapidly and intensively to N additions than the pine and mixed forests,and exhibited some significant negative symptoms,e.g.,soil acidification,Al mobilization and leaching of base cations from soil.The pine and mixed forests responded slowly to N additions and exhibited no significant response of soil cations.Response of soil exchangeable cations to N deposition varied in the forests of subtropical China,depending on soil N status and land-nse history.

Microbial activities in forest soils exposed to chronic depositions from a lignite power plant

Energy Technology Data Exchange (ETDEWEB)

Klose, S.; Wernecke, K.D.; Makeschin, F. [Technical University of Dresden, Tharandt (Germany)

2004-12-01

Atmospheric emissions of fly ash and SO{sub 2} from lignite-fired power plants strongly affect large forest areas in Germany. The impact of different deposition loads on the microbial biomass and enzyme activities was studied at three forest sites (Picea abies (L.) Karst.) along an emission gradient of 3, 6, and 15 km downwind of a coal-fired power plant, representing high, moderate and low emission rates. An additional site at a distance of 3 km from the power plant was chosen to study the influence of forest type on microbial parameters in coniferous forest soils under fly ash and SO{sub 2} emissions. Soil microbial biomass C and N, CO{sub 2} evolved and activities of L-asparaginase, L-glutaminase, beta-glucosidase, acid phosphatase and arylsulfatase (expressed on dry soil and organic C basis) were determined in the forest floor (L, Of and Oh horizon) and mineral top soil (0-10 cm). It is concluded that chronic fly ash depositions decrease litter decomposition by influencing specific microbial and enzymatic processes in forest soils.

Soil carbon sequestration and changes in fungal and bacterial biomass following incorporation of forest residues

Science.gov (United States)

Matt D. Busse; Felipe G. Sanchez; Alice W. Ratcliff; John R. Butnor; Emily A. Carter; Robert F. Powers

2009-01-01

Sequestering carbon (C) in forest soils can benefit site fertility and help offset greenhouse gas emissions. However, identifying soil conditions and forest management practices which best promote C accumulation remains a challenging task. We tested whether soil incorporation of masticated woody residues alters short-term C storage at forested sites in western and...

Effect of 40 and 80 Years of Conifer Regrowth on Soil Microbial Activities and Community Structure in Subtropical Low Mountain Forests

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Ed-Haun Chang

2016-10-01

Full Text Available The effects of long-term reforestation on soil microbial communities and biomass are poorly understood. This study was conducted on two coniferous plantations: Cunninghamia konishii Hayata, planted 40 years ago (CONIF-40, and Calocedrus formosana (Florin Florin, planted 80 years ago (CONIF-80. An adjacent natural broadleaf forest (BROAD-Nat was used as a control. We determined microbial biomass C and N contents, enzyme activities, and community composition (via phospholipid fatty acid [PLFA] assessment. Both microbial biomass and PLFA content were higher in the summer than in the winter and differed among the forests in summer only. Total PLFA, total bacterial, gram-positive bacterial, gram-negative bacterial, and vesicular arbuscular mycorrhizal fungal contents followed the same pattern. Total fungal content and the ratios of fungi to bacteria and of gram-positive to gram-negative bacteria were highest in CONIF-40, with no difference between the other forests. Principal component analysis of PLFA contents revealed that CONIF-40 communities were distinct from those of CONIF-80 and BROAD-Nat. Our results suggest that vegetation replacement during reforestation exerts a prolonged impact on the soil microbial community. The understory broadleaf shrubs and trees established after coniferous plantation reforestation may balance out the effects of coniferous litter, contributing to bacterial recovery.

Thermal characteristics and bacterial diversity of forest soil in the Haean basin of Korea.

Science.gov (United States)

Kim, Heejung; Lee, Jin-Yong; Lee, Kang-Kun

2014-01-01

To predict biotic responses to disturbances in forest environments, it is important to examine both the thermophysical properties of forest soils and the diversity of microorganisms that these soils contain. To predict the effects of climate change on forests, in particular, it is essential to understand the interactions between the soil surface, the air, and the biological diversity in the soil. In this study, the temperature and thermal properties of forest soil at three depths at a site in the Haean basin of Korea were measured over a period of four months. Metagenomic analyses were also carried out to ascertain the diversity of microorganisms inhabiting the soil. The thermal diffusivity of the soil at the study site was 5.9 × 10(-8) m(2) · s(-1). The heat flow through the soil resulted from the cooling and heating processes acting on the surface layers of the soils. The heat productivity in the soil varied through time. The phylum Proteobacteria predominated at all three soil depths, with members of Proteobacteria forming a substantial fraction (25.64 to 39.29%). The diversity and richness of microorganisms in the soil were both highest at the deepest depth, 90 cm, where the soil temperature fluctuation was the minimum.

Thermal Characteristics and Bacterial Diversity of Forest Soil in the Haean Basin of Korea

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Heejung Kim

2014-01-01

Full Text Available To predict biotic responses to disturbances in forest environments, it is important to examine both the thermophysical properties of forest soils and the diversity of microorganisms that these soils contain. To predict the effects of climate change on forests, in particular, it is essential to understand the interactions between the soil surface, the air, and the biological diversity in the soil. In this study, the temperature and thermal properties of forest soil at three depths at a site in the Haean basin of Korea were measured over a period of four months. Metagenomic analyses were also carried out to ascertain the diversity of microorganisms inhabiting the soil. The thermal diffusivity of the soil at the study site was 5.9 × 10−8 m2·s−1. The heat flow through the soil resulted from the cooling and heating processes acting on the surface layers of the soils. The heat productivity in the soil varied through time. The phylum Proteobacteria predominated at all three soil depths, with members of Proteobacteria forming a substantial fraction (25.64 to 39.29%. The diversity and richness of microorganisms in the soil were both highest at the deepest depth, 90 cm, where the soil temperature fluctuation was the minimum.

Isolation and identification of soil fungi isolates from forest soil for flooded soil recovery

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Hazwani Aziz, Nor; Zainol, Norazwina

2018-04-01

Soil fungi have been evaluated for their ability in increasing and recovering nitrogen, phosphorus and potassium content in flooded soil and in promoting the growth of the host plant. Host plant was cultivated in a mixture of fertile forest soil (nutrient-rich soil) and simulated flooded soil (nutrient-poor soil) in an optimized soil condition for two weeks. The soil sample was harvested every day until two weeks of planting and was tested for nitrogen, phosphorus and potassium concentration. Soil fungi were isolated by using dilution plating technique and was identified by Biolog’s Microbial Systems. The concentration of nitrogen, phosphorus, and potassium was found to be increasing after two weeks by two to three times approximately from the initial concentration recorded. Two fungi species were identified with probability more than 90% namely Aspergillus aculeatus and Paecilomyces lilacinus. Both identified fungi were found to be beneficial in enhancing plant growth and increasing the availability of nutrient content in the soil and thus recovering the nutrient content in the flooded soil.

Nature and Properties of Some Forest Soils in the Mhite Mountains of New Hampshire

Science.gov (United States)

M.C. Hoyle; M.C. Hoyle

1973-01-01

Forested, podzol soils in the White Mountains of New Hampshire have developed in granitic, glacial material. They are coarse textured, acidic, and infertile. As a result of the latter condition, these soils can sustain a forest, but that forest is not healthy and vigorous.

Contrasting the microbiomes from forest rhizosphere and deeper bulk soil from an Amazon rainforest reserve.

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Fonseca, Jose Pedro; Hoffmann, Luisa; Cabral, Bianca Catarina Azeredo; Dias, Victor Hugo Giordano; Miranda, Marcio Rodrigues; de Azevedo Martins, Allan Cezar; Boschiero, Clarissa; Bastos, Wanderley Rodrigues; Silva, Rosane

2018-02-05

Pristine forest ecosystems provide a unique perspective for the study of plant-associated microbiota since they host a great microbial diversity. Although the Amazon forest is one of the hotspots of biodiversity around the world, few metagenomic studies described its microbial community diversity thus far. Understanding the environmental factors that can cause shifts in microbial profiles is key to improving soil health and biogeochemical cycles. Here we report a taxonomic and functional characterization of the microbiome from the rhizosphere of Brosimum guianense (Snakewood), a native tree, and bulk soil samples from a pristine Brazilian Amazon forest reserve (Cuniã), for the first time by the shotgun approach. We identified several fungi and bacteria taxon significantly enriched in forest rhizosphere compared to bulk soil samples. For archaea, the trend was the opposite, with many archaeal phylum and families being considerably more enriched in bulk soil compared to forest rhizosphere. Several fungal and bacterial decomposers like Postia placenta and Catenulispora acidiphila which help maintain healthy forest ecosystems were found enriched in our samples. Other bacterial species involved in nitrogen (Nitrobacter hamburgensis and Rhodopseudomonas palustris) and carbon cycling (Oligotropha carboxidovorans) were overrepresented in our samples indicating the importance of these metabolic pathways for the Amazon rainforest reserve soil health. Hierarchical clustering based on taxonomic similar microbial profiles grouped the forest rhizosphere samples in a distinct clade separated from bulk soil samples. Principal coordinate analysis of our samples with publicly available metagenomes from the Amazon region showed grouping into specific rhizosphere and bulk soil clusters, further indicating distinct microbial community profiles. In this work, we reported significant shifts in microbial community structure between forest rhizosphere and bulk soil samples from an Amazon

Species richness and soil properties in Pinus ponderosa forests: A structural equation modeling analysis

Science.gov (United States)

Laughlin, D.C.; Abella, S.R.; Covington, W.W.; Grace, J.B.

2007-01-01

Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. We evaluated multivariate models of plant species richness using structural equation modeling. Results: Richness was highest at intermediate levels of understory plant cover, suggesting that both colonization success and competitive exclusion can limit richness in this system. We did not detect a reciprocal positive effect of richness on plant cover. Richness was strongly related to soil nitrogen in the model, with evidence for both a direct negative effect and an indirect non-linear relationship mediated through understory plant cover. Soil organic matter appeared to have a positive influence on understory richness that was independent of soil nitrogen. Richness was lowest where the forest overstory was densest, which can be explained through indirect effects on soil organic matter, soil nitrogen and understory cover. Finally, model results suggest a variety of direct and indirect processes whereby mineral soil properties can influence richness. Conclusions: Understory plant species richness and plant cover in P. ponderosa forests appear to be significantly influenced by soil organic matter and nitrogen, which are, in turn, related to overstory density and composition and mineral soil properties. Thus, soil properties can impose direct and indirect constraints on local species diversity in ponderosa pine forests. ?? IAVS; Opulus Press.

Comparison of vegetation patterns and soil nutrient relations in an oak-pine forest and a mixed deciduous forest on Long Island, New York

Energy Technology Data Exchange (ETDEWEB)

Peterson, S.C.; Curtis, P.S.

1980-11-01

An analysis of soil nutrient relations in two forest communities on Long Island, NY, yielded a correlation between the fertility of the top-soil and vegetational composition. The oak-pine forest soils at Brookhaven National Laboratory contain lower average concentrations of NH/sub 3/, Ca, K, and organic matter than the mixed deciduous forest soils in the Stony Brook area. The pH of the topsoil is also more acidic at Brookhaven. The observed differences between localities are greater than within-locality differences between the two soil series tested (Plymouth and Riverhead), which are common to both localities. Nutrient concentrations in the subsoil are not consistently correlated with either locality or soil series, although organic matter and NH/sub 3/ show significantly higher concentrations at Stony Brook. Supporting data on density and basal area of trees and coverage of shrubs and herbs also reveals significant variation between the two forest communities. An ordination of the vegetation data shows higher similarity within than between localities, while no obvious pattern of within-locality variation due to soil series treatments is apparent. These data support the hypothesis that fertility gradients may influence forest community composition and structure. This hypothesis is discussed with reference to vegetation-soil interactions and other factors, such as frequency of burning, which may direct the future development of the Brookhaven oak-pine forest.

Estimating the collapse of aggregated fine soil structure in a mountainous forested catchment.

Science.gov (United States)

Mouri, Goro; Shinoda, Seirou; Golosov, Valentin; Chalov, Sergey; Shiiba, Michiharu; Hori, Tomoharu; Oki, Taikan

2014-06-01

This paper describes the relationship of forest soil dryness and antecedent rainfall with suspended sediment (SS) yield due to extreme rainfall events and how this relationship affects the survival of forest plants. Several phenomena contribute to this relationship: increasing evaporation (amount of water vapour discharged from soil) due to increasing air temperature, decreasing moisture content in the soil, the collapse of aggregates of fine soil particles, and the resulting effects on forest plants. To clarify the relationships among climate variation, the collapse of soil particle aggregates, and rainfall-runoff processes, a numerical model was developed to reproduce such aggregate collapse in detail. The validity of the numerical model was confirmed by its application to the granitic mountainous catchment of the Nagara River basin in Japan and by comparison with observational data. The simulation suggests that important problems, such as the collapse of forest plants in response to decreases in soil moisture content and antecedent rainfall, will arise if air temperature continues to increase. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

An observational study of the carbon-sink strength of East Asian subtropical evergreen forests

International Nuclear Information System (INIS)

Tan Zhenghong; Zhang Yiping; Zhang Yongjiang; Song Qinhai; Cao Kunfang; Schaefer, D A; Liu Yuhong; Liang Naishen; Hsia, Yue-Joe; Zhou Guoyi; Li Yuelin; Yan Junhua; Juang, Jehn-Yih; Chu Housen; Yu Guirui; Sun Xiaomin

2012-01-01

Relatively little is known about the effects of regional warming on the carbon cycle of subtropical evergreen forest ecosystems, which are characterized by year-round growing season and cold winters. We investigated the carbon balance in three typical East Asia subtropical evergreen forests, using eddy flux, soil respiration and leaf-level measurements. Subtropical evergreen forests maintain continuous, high rates of photosynthetic activity, even during winter cold periods. Warm summers enhance photosynthetic rates in a limited way, because overall ecosystem productivity is primarily restrained by radiation levels during the warm period. Conversely, warm climates significantly enhance the respiratory carbon efflux. The finding of lower sensitivity of photosynthesis relative to that of respiration suggests that increased temperature will weaken the carbon-sink strength of East Asia subtropical evergreen forests. (letter)

Predicting forest dieback in Maine, USA: a simple model based on soil frost and drought

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Allan N.D. Auclair; Warren E. Heilman; Blondel. Brinkman

2010-01-01

Tree roots of northern hardwoods are shallow rooted, winter active, and minimally frost hardened; dieback is a winter freezing injury to roots incited by frost penetration in the absence of adequate snow cover and exacerbated by drought in summer. High soil water content greatly increases conductivity of frost. We develop a model based on the sum of z-scores of soil...

[Effects of forest regeneration patterns on the quantity and chemical structure of soil solution dissolved organic matter in a subtropical forest.

Science.gov (United States)

Yuan, Xiao Chun; Lin, Wei Sheng; Pu, Xiao Ting; Yang, Zhi Rong; Zheng, Wei; Chen, Yue Min; Yang, Yu Sheng

2016-06-01

Using the negative pressure sampling method, the concentrations and spectral characte-ristics of dissolved organic matter (DOM) of soil solution were studied at 0-15, 15-30, 30-60 cm layers in Castanopsis carlesii forest (BF), human-assisted naturally regenerated C. carlesii forest (RF), C. carlesii plantation (CP) in evergreen broad-leaved forests in Sanming City, Fujian Pro-vince. The results showed that the overall trend of dissolved organic carbon (DOC) concentrations in soil solution was RF>CP>BF, and the concentration of dissolved organic nitrogen (DON) was highest in C. carlesii plantation. The concentrations of DOC and DON in surface soil (0-15 cm) were all significantly higher than in the subsurface (30-60 cm). The aromatic index (AI) was in the order of RF>CP>BF, and as a whole, the highest AI was observed in the surface soil. Higher fluorescence intensity and a short wave absorption peak (320 nm) were observed in C. carlesii plantation, suggesting the surface soil of C. carlesii plantation was rich in decomposed substance content, while the degree of humification was lower. A medium wave absorption peak (380 nm) was observed in human-assisted naturally regenerated C. carlesii forest, indicating the degree of humification was higher which would contribute to the storage of soil fertility. In addition, DOM characte-ristics in 30-60 cm soil solution were almost unaffected by forest regeneration patterns.

Radionuclide transport along a boreal hill slope - elevated soil water concentrations in riparian forest soils

Energy Technology Data Exchange (ETDEWEB)

Lidman, Fredrik; Boily, Aasa; Laudon, Hjalmar [Dept. of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901 83 Umeaa (Sweden); Koehler, Stephan J. [Dept. of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P.O. 7050, 750 07 Uppsala (Sweden)

2014-07-01

The transport of radionuclides from forest ecosystems and out into surface waters is a crucial process for understanding the long-term fate of radionuclides in the boreal landscape. Boreal forests are typically dominated by podzol soils, but the streams draining the forests are often lined by highly organic, often peat-like soils, which the radionuclides must pass through in order to reach the stream. This so-called riparian zone therefore represents a fundamentally different biogeochemical environment than ordinary forest soils, e.g. by exhibiting significantly lower pH and higher concentrations of organic colloids, which significantly can affect the mobility of many radionuclides. Since the riparian zone is the last terrestrial environment that the groundwater is in contact with before it enters the stream, previous research has demonstrated its profound impact on the stream water chemistry. Hence, the riparian soils should also be important for the transport and accumulation of radionuclides. Therefore, soil water was sampled using suction lysimeters installed at different depths along a 22 m long forested hill slope transect in northern Sweden, following the flow pathway of the groundwater from the uphill podzol to the riparian zone near the stream channel. The analyses included a wide range of hydrochemical parameters and many radiologically important elements, e.g. U, Th, Ni, C, Sr, Cs, REEs and Cl. The sampling was repeated ten times throughout a year in order to also capture the temporal variability of the soil water chemistry. The water chemistry of the investigated transect displayed a remarkable change as the groundwater approached the stream channel. Strongly increased concentrations of many elements were observed in the riparian soils. For instance, the concentrations of Th were more than 100 times higher than in the riparian zone than in the uphill forest, suggesting that the riparian zone may be a hotspot for radionuclide accumulation. The reason

Overcoming of Soil Contamination with Pesticides in Forest Nurseries Using the Activity of Microorganisms

Directory of Open Access Journals (Sweden)

Irina A. Freiberg

2010-01-01

Full Text Available The use of pesticides during cultivation of pine seedlings in forest nurseries resultsin the formation two phenotypes of teratomorph seedlings – conditionally normal andabnormal. Growing forest cultures from teratomorph seedlings leads to their low survivalrate. It is known that pesticides and their metabolic products can remain in soil for manyyears. It is therefore impossible to rely only on natural degradation of pesticides in soil. Apromising way of removing pesticides from soil is their microbiological decomposition.This method is preferable because there is a meliorative organic substance not far from forestnurseries – i.e. forest litter rich in microorganisms. The purpose of these experimentswas to examine the influence of forest litter applied on pesticide decomposition in soil andmorphology of pine seedlings. The rates of forest litter that were most effective in decompositionof pesticides and the activity of microbial communities in litter, depending on foreststand structure, were determined. Estimation of that action was based on the morphologyof seedlings (rate of pine seedlings with normal, conditionally normal and abnormalphenotypes, intensity of CO2 emission from soil and catalase activity, which correlates withthe number of soil microorganisms. The results of these experiments showed the mosteffective activity of forest litter at the application rate of 20 kg/m2. The number of seedlingswith normal phenotype rose from 32% up to 40%. Besides, it was noted that saprophyteswere most effective in pine forest litter, which is characterized by a more acid reaction ofsoil solution, while most others were rich in fungi. The highest number of normal phenotypeseedlings, intensity of CO2 emission and activity of soil catalase were correlated withthe microbiological activity of the applied pine forest litter.

Evidence that soil aluminum enforces site fidelity of southern New England forest trees

Science.gov (United States)

S. W. Bigelow; C. D. Canham

2010-01-01

Tree species composition of hardwood forests of the northeastern United States corresponds with soil chemistry, and differential performance along soil calcium (Ca) gradients has been proposed as a mechanism for enforcing this fidelity of species to site. We conducted studies in a southern New England forest to test if surface-soil Ca is more important than other...

Responses of soil fungi to logging and oil palm agriculture in Southeast Asian tropical forests.

Science.gov (United States)

McGuire, K L; D'Angelo, H; Brearley, F Q; Gedallovich, S M; Babar, N; Yang, N; Gillikin, C M; Gradoville, R; Bateman, C; Turner, B L; Mansor, P; Leff, J W; Fierer, N

2015-05-01

Human land use alters soil microbial composition and function in a variety of systems, although few comparable studies have been done in tropical forests and tropical agricultural production areas. Logging and the expansion of oil palm agriculture are two of the most significant drivers of tropical deforestation, and the latter is most prevalent in Southeast Asia. The aim of this study was to compare soil fungal communities from three sites in Malaysia that represent three of the most dominant land-use types in the Southeast Asia tropics: a primary forest, a regenerating forest that had been selectively logged 50 years previously, and a 25-year-old oil palm plantation. Soil cores were collected from three replicate plots at each site, and fungal communities were sequenced using the Illumina platform. Extracellular enzyme assays were assessed as a proxy for soil microbial function. We found that fungal communities were distinct across all sites, although fungal composition in the regenerating forest was more similar to the primary forest than either forest community was to the oil palm site. Ectomycorrhizal fungi, which are important associates of the dominant Dipterocarpaceae tree family in this region, were compositionally distinct across forests, but were nearly absent from oil palm soils. Extracellular enzyme assays indicated that the soil ecosystem in oil palm plantations experienced altered nutrient cycling dynamics, but there were few differences between regenerating and primary forest soils. Together, these results show that logging and the replacement of primary forest with oil palm plantations alter fungal community and function, although forests regenerating from logging had more similarities with primary forests in terms of fungal composition and nutrient cycling potential. Since oil palm agriculture is currently the mostly rapidly expanding equatorial crop and logging is pervasive across tropical ecosystems, these findings may have broad applicability.

The feature and distribution of 137Cs in the forest soil

International Nuclear Information System (INIS)

Narazaki, Yukinori

2002-01-01

The 137 Cs concentration in an undisturbed upper layer of naked land in Fukuoka Prefecture decreased exponentially from 1969 to 1999 with the apparent half-life of 7 years. The ratio of 137 Cs concentration in the lower layer of the soil to that in the upper layer was about 1/5. The concentration of 137 Cs, 40 K, and stable Cs and the soil profile consisting of loss on ignition, pH, and electric conductivity were determined in the 48 samples collected in the forests and the neighboring naked land from 1991 to 1998. The 137 Cs concentration in the forest soils ranged from 1 to 424 Bq/kg dry wt, 131 Bq/kg dry wt on average, although 137 Cs was hardly detected in the naked soil around the forest. There was no regional difference in the distribution of the 137 Cs concentration, and it varied with pH and electric conductivity in the soil. Further, it tended to be higher in the deciduous woodland than in the evergreen woodland. (author)

[Species composition and diversity of soil mesofauna in the 'Holy Hills' fragmentary tropical rain forest of Xishuangbanna, China].

Science.gov (United States)

Yang, X; Sha, L

2001-04-01

The species composition and diversity of soil mesofauna were examined in fragmented dry tropical seasonal rainforest of tow 'Holy Hills' of Dai nationality, compared with the continuous moist tropical seasonal rain forest of Nature Reserve in Xishuangbanna area. 5 sample quadrats were selected along the diagonal of 20 m x 20 m sampling plot, and the samples of litterfall and 0-3 cm soil were collected from each 50 cm x 10 cm sample quadrat. Animals in soil sample were collected by using dry-funnel(Tullgren's), were identified to their groups according to the order. The H' index, D.G index and the pattern of relative abundance of species were used to compare the diversity of soil mesofauna. The results showed that the disturbance of vegetation and soil resulted by tropical rainforest fragmentation was the major factor affecting the diversity of soil mesofauna. Because the fragmented forest was intruded by some pioneer tree species and the "dry and warm" effect operated, this forest had more litterfall on the floor and more humus in the soil than the continuous moist rain forest. The soil condition with more soil organic matter, total N and P, higher pH value and lower soil bulk density became more favorable to the soil mesofauna. Therefore, the species richness, abundance and diversity of soil mesofauna in fragmented forests were higher than those in continuous forest, but the similarity of species composition in fragmented forest to the continuous forest was minimal. Soil mesofauna diversity in fragmented forests did not change with decreasing fragmented area, indicating that there was no species-area effect operation in this forest. The pattern of relative abundance of species in these forest soils was logarithmic series distribution.

Visually Determined Soil Disturbance Classes Used as Indices of Forest Harvesting Disturbance

Science.gov (United States)

W. Michael Aust; James A. Burger; Emily A. Carter; David P. Preston; Steven C. Patterson

1998-01-01

Visual estimates of soil and site disturbances are used by foresters, soil scientists, logging supervisors. and machinery operators to minimize harvest disturbances to forest sites, to evaluate compliance with forestry Best Management Practices (BMPs), and to determine the need for ameliorative practices such as tnechanical site preparation. Although estimates are...

The effect of increasing salinity and forest mortality on soil nitrogen and phosphorus mineralization in tidal freshwater forested wetlands

Science.gov (United States)

Noe, Gregory B.; Krauss, Ken W.; Lockaby, B. Graeme; Conner, William H.; Hupp, Cliff R.

2013-01-01

Tidal freshwater wetlands are sensitive to sea level rise and increased salinity, although little information is known about the impact of salinification on nutrient biogeochemistry in tidal freshwater forested wetlands. We quantified soil nitrogen (N) and phosphorus (P) mineralization using seasonal in situ incubations of modified resin cores along spatial gradients of chronic salinification (from continuously freshwater tidal forest to salt impacted tidal forest to oligohaline marsh) and in hummocks and hollows of the continuously freshwater tidal forest along the blackwater Waccamaw River and alluvial Savannah River. Salinification increased rates of net N and P mineralization fluxes and turnover in tidal freshwater forested wetland soils, most likely through tree stress and senescence (for N) and conversion to oligohaline marsh (for P). Stimulation of N and P mineralization by chronic salinification was apparently unrelated to inputs of sulfate (for N and P) or direct effects of increased soil conductivity (for N). In addition, the tidal wetland soils of the alluvial river mineralized more P relative to N than the blackwater river. Finally, hummocks had much greater nitrification fluxes than hollows at the continuously freshwater tidal forested wetland sites. These findings add to knowledge of the responses of tidal freshwater ecosystems to sea level rise and salinification that is necessary to predict the consequences of state changes in coastal ecosystem structure and function due to global change, including potential impacts on estuarine eutrophication.

Long term field evaluation of phosphate rock and superphosphate in acid soils of Hungary; Incubation and pot experiments

International Nuclear Information System (INIS)

Nemeth, T.; Osztoics, E.; Csatho, P.; Radimszky, L.; Baczo, G.Y.

2002-01-01

A series of experiments was conducted to compare the agronomic effectiveness of phosphate rock (from Algeria) and of single superphosphate (from Russia, Kola) on a moderately acidic pseudogley brown forest soil (Szentgyoergyvoelgy) and on a slightly acidic chernozem brown forest soil (Kompolt). Dynamics of water-soluble and ammonium lactate-soluble P-contents (AL-P) and soil pH-H 2 O changes were studied in a half-year long incubation experiment. A follow-up pot experiment with the same soils was carried out with winter rape as test plants. Both experiments were set up with similar P fertilizer sources and P rates (100, 200, and 400 mg mineral acid soluble P 2 O 5 per kg soil). At the beginning of incubation experiment, the water-soluble P content of the pseudogley brown forest soil was influenced by both the sources of P and the experimental conditions. The water-soluble P content decreased with time. After the 15 th to 20 th day of incubation, when the fast binding process of the water-soluble P ended, the effects of the P forms decreased. In this stage, the effects of environmental conditions depended on the form of the P fertilizer. The water-soluble P content of the phosphate rock-treated samples was affected to a great extent by soil water content, while the incubation temperature had a greater effect in soils treated with superphosphate. The AL-P content of soils was increased similarly by addition of equal rates of phosphate rock and super-phosphate at the beginning of incubation. The AL-P content of phosphate rock-treated soils was higher throughout the incubation period than of the superphosphate-treated soils -treated. Temperature had a greater effect on the AL-P content of soils than soil water content. As the AL-extraction may dissolve a substantial amount of the undecomposed phosphate rock, this method is not applicable to soil testing of available P forms from phosphate rock-treated soils. Initial soil pH decreased on average by 0.5 units in the

Soil changes in forest ecosystems: evidence for and probable causes