scholarly journals Changes in Soil Chemistry and Foliar Metabolism of Himalayan Cedar (Cedrus deodara) and Himalayan Spruce (Picea smithiana) along an Elevational Gradient at Kufri, HP, India: The Potential Roles of Regional Pollution and Localized Grazing

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 400
Author(s):  
Rakesh Minocha ◽  
Alexandra R. Contosta ◽  
Gregory B. Lawrence ◽  
Ravinder K. Kohli ◽  
Subhash C. Minocha ◽  
...  
Keyword(s):  
Soil Chemistry ◽  
Mineral Soil ◽  
Forest Health ◽  
Elevational Gradient ◽  
High Elevation ◽  
Metabolic Profiles ◽  
Cedrus Deodara ◽  
High Elevation Site ◽  
Picea Smithiana ◽  
The Impact

We investigated changes in soil chemistry and foliar metabolism of Himalayan cedar [Cedrus deodara (Roxb. Ex Lamb.) G.Don] and Himalayan spruce [Picea smithiana (Wall.) Boiss] trees along a steep elevational gradient in the lower Himalayan Mountains at Kufri, Himachal Pradesh (HP), India. The foliar and soil samples were collected from four locations along a 300 m elevational gradient at ridge, high-, mid-, and low-elevation sites within the forested Shimla Water Catchment Wildlife Sanctuary that provides water for the city of Shimla, HP,. Observations at the time of sampling revealed that the high-elevation site was being heavily grazed. Soils collected at the four sites showed differences in soil chemistry along the gradient. Surface soils (top 10 cm) at the high-elevation site had the highest concentrations of carbon, nitrogen, calcium, magnesium, phosphorus, organic matter, and effective cation exchange capacity, possibly caused by grazing. Mineral soils were slightly acidic at all sites except the mid-elevation site, which was extremely acidic in the upper mineral soil. Similar to surface soil chemistry, foliar metabolism was also comparatively unique for high elevation. In Himalayan cedar foliage, higher concentrations of soluble proteins, polyamines, amino acids, and potassium were observed at the high-elevation site as compared to the ridge, mid and low elevations. No major differences were observed in the metabolic profiles of cedar between the ridge and low elevation ranges. Spruce foliage was sampled only from the ridge and low elevations and its metabolic profiles suggested healthier conditions at the low elevation. The results of the study demonstrate the impact of the interplay between local and regional drivers of forest health on cedar and spruce trees in a forested catchment that acts as a water source for downstream communities.

Playbacks revisited: asymmetry in behavioural response across an acoustic boundary between two parapatric bird species

Behaviour ◽  
2015 ◽  
Vol 152 (14) ◽  
pp. 1933-1951 ◽  
Author(s):  
Tamsin Burbidge ◽  
Thari Parson ◽  
Paula C. Caycedo-Rosales ◽  
Carlos Daniel Cadena ◽  
Hans Slabbekoorn
Keyword(s):  
Gene Flow ◽  
Response Pattern ◽  
Bird Species ◽  
Elevational Gradient ◽  
High Elevation ◽  
Secondary Contact ◽  
Potential Contribution ◽  
Asymmetric Response ◽  
Singing Style ◽  
The Impact

Behavioural barriers to gene flow can play a key role in speciation and hybridisation. Birdsong is well-known for its potential contribution to such behavioural barriers as it may affect gene flow through an effect on territorial and mating success across population boundaries. Conspecific recognition and heterospecific discrimination of acoustic variation can prevent or limit hybridization in areas where closely related species meet. Here we tested the impact of song differences on territorial response levels between two adjacent Henicorhina wood-wren species along an elevational gradient in Colombia. In an earlier study, playback results had revealed an asymmetric response pattern, with low-elevation H. leucophrys bangsi responding strongly to any conspecific or heterospecific song variant, whereas high-elevation H. anachoreta birds discriminated, responding more strongly to their own songs than to those of bangsi. However, in that study we could not exclude a role for relative familiarity to the song stimuli. In the current study we confirm the asymmetric response pattern with song stimuli recorded close to and on both sides of the distinct acoustic boundary. Furthermore, we also show a previously unnoticed divergence in singing style between these two wood-wren species, which may contribute to an acoustically guided barrier to hybridization in this secondary contact zone.

The impact of ectoparasitism on thermoregulation in Yarrow’s Spiny Lizards (Sceloporus jarrovii)

2019 ◽  
Vol 97 (11) ◽  
pp. 1004-1012 ◽  
Author(s):  
N. Johnson ◽  
A.H. Lymburner ◽  
G. Blouin-Demers
Keyword(s):  
Body Temperature ◽  
Immune Responses ◽  
Positive Association ◽  
Elevational Gradient ◽  
High Elevation ◽  
Negative Association ◽  
The Mean ◽  
The Impact ◽  
Ectoparasite Load

Parasites are ubiquitous and can have large impacts on the fitness of their hosts. The effects of ectoparasites on physiology, behaviour, and immune function suggest that they could be part of the factors which impact thermoregulation. We tested the hypothesis that ectoparasites impact thermoregulation in Yarrow’s Spiny Lizards (Sceloporus jarrovii Cope in Yarrow, 1875) living along an elevational gradient. We predicted a positive association between ectoparasite load and body temperature (Tb), and a negative association between ectoparasite load and effectiveness of thermoregulation (de – db index). We also predicted that the impacts of ectoparasites would be greatest at high elevation where thermal quality of the environment is low because the costs of thermoregulation increase with elevation and these costs can impact thermal immune responses. We found a significant association between the number of chiggers (Trombiculoidea) harboured by lizards and Tb that depended on elevation, but no association between ectoparasite load and de – db index. The mean chigger infection rate was associated with a ΔTb of +0.18 °C at low elevation (consistent with fever) and of –1.07 °C at high elevation (consistent with hypothermia). These findings suggest that parasitism by chiggers impacts lizard Tb in a way that depends on environmental thermal quality.

Linking shrimp assemblages with rates of detrital processing along an elevational gradient in a tropical stream

2001 ◽  
Vol 58 (3) ◽  
pp. 470-478 ◽  
Author(s):  
James G March ◽  
Jonathan P Benstead ◽  
Catherine M Pringle ◽  
Mark W Ruebel
Keyword(s):  
Laboratory Experiments ◽  
Elevational Gradient ◽  
High Elevation ◽  
Decay Rates ◽  
Minor Role ◽  
Tropical Stream ◽  
Leaf Decay ◽  
High Elevation Site ◽  
A Minor ◽  
Insect Biomass

We experimentally excluded freshwater shrimp assemblages (Atyidae, Xiphocarididae, and Palaemonidae) to examine their effects on detrital processing and benthic insect biomass at three sites along an elevational gradient in a tropical stream in Puerto Rico. We also determined which shrimp taxon was responsible for leaf decay in a subsequent laboratory experiment. At the high-elevation site, the shrimp assemblage was dominated by Atya spp. and Xiphocaris elongata, and leaf decay rates were significantly faster in the presence of shrimps than in their absence. Laboratory experiments showed that this was primarily due to direct consumption of leaves by Xiphocaris. Shrimps had no effect on leaf decay rates at mid- and low-elevation sites where there were higher proportions of Macrobrachium spp. shrimps (which prey on Xiphocaris). Laboratory experiments showed that Xiphocaris consumed significantly less leaf material and experienced significantly higher mortality in the presence of Macrobrachium. Shrimp exclusion resulted in significantly less and significantly more insect biomass at the high- and low-elevation sites, respectively; no difference was found at the mid-elevation site. Insects played a minor role in leaf decay. Results show a strong linkage between shrimp assemblages and rates of detrital decay and illustrate the importance of conducting experiments at multiple sites.

scholarly journals Douglas fir and Norway spruce admixtures to European beech along a site gradient in Northern Germany – Are soil nutrient conditions affected?

2020 ◽  
Author(s):  
Estela Covre Foltran ◽  
Christian Ammer ◽  
Norbert Lamersdorf
Keyword(s):  
Soil Properties ◽  
Norway Spruce ◽  
Soil Ph ◽  
Soil Chemistry ◽  
Mineral Soil ◽  
European Beech ◽  
Douglas Fir ◽  
Model Systems ◽  
Northern Germany ◽  
The Impact

AbstractBackgroundThe establishment of economically valuable conifers into a matrix of native broadleaved tree species may serve as model systems that combine economic interests and nature conservation. However, it is not clear which effects the enrichment by conifers has on soil properties.MethodsOur study analyzed pure mature European beech (Fagus sylvatica), Douglas fir (Pseudotsuga menziesii) and Norway spruce (Picea abies) stands as well as mixtures of beech with either Douglas fir or spruce along a soil and climate gradient in Northern Germany. We determined chemical soil properties of the O-horizon and upper mineral soil horizons. Soil pH, concentrations and storage of exchangeable cations, base saturation (BS) as well total P contents were analyzed.ResultsWe observed lowest pH and BS in spruce stands while beech showed higher BS. The impact of Douglas fir on soil chemistry varied depending on the site. Under Douglas fir-beech mixtures, mineral soil pH and BS were higher than under the respective Douglas-fir stands at nutrient-poor sandy soils. While spruce and its admixture deplete soil exchangeable Ca and Mg more than Douglas fir mixed with. Total soil exchangeable K under mixed stands were among the highest, independent of the site condition.ConclusionsOverall, our study suggest that the enrichment of beech stands by Douglas fir does not cause unexpected and detrimental changes of soil acidity and does not strongly affect soil exchangeable base cation reserves when compared to European beech. Instead, admixtures of Douglas-fir seem to lead to smaller changes in pH, CEC and BS than those of Norway spruce. Therefore, forest management may consider mixtures of European beech and Douglas fir as a reasonable management option without apprehending negative effects on soil chemistry.

scholarly journals Provenance Variation in Early Survival, Growth, and Carbon Isotope Discrimination of Southwestern Ponderosa Pine Growing in Three Common Gardens across an Elevational Gradient

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1561
Author(s):  
Aalap Dixit ◽  
Thomas Kolb ◽  
Owen Burney ◽  
Karen Mock ◽  
Kevin Grady
Keyword(s):  
Growth Rate ◽  
Carbon Isotope ◽  
Ponderosa Pine ◽  
Carbon Isotope Discrimination ◽  
Elevational Gradient ◽  
High Elevation ◽  
Provenance Variation ◽  
Isotope Discrimination ◽  
Common Gardens ◽  
High Elevation Site

We investigated early survival, growth, and carbon isotope discrimination of ponderosa pine (Pinus ponderosa Lawson & C. Lawson var. scopulorum Engelm.) seedlings from different provenances using common gardens across an elevational gradient in order to examine the potential for adaptation to extreme environments and constraints to artificial regeneration. Twenty-one provenances from a range of elevations across Arizona and New Mexico were planted in three common gardens: a high-elevation meadow in aspen-mixed conifer forest, a mid-elevation ponderosa pine forest, and a low-elevation pinyon juniper woodland. Two years after planting in 2018, survival was highest at the mid-elevation site (54%), low at the high-elevation site (1.5%), and 0% at the low-elevation site. At the hot and dry low-elevation site, provenances from low-elevations survived longer than provenances from mid- and high-elevations, which suggests greater drought tolerance of low-elevation provenances. Mortality agents changed from abiotic (drought) to biotic (herbivory) with an increase in elevation across sites. High mortality of seedlings planted at high-elevation sites from biotic agents, such as rodents, may challenge efforts to establish ponderosa pine in assisted migration projects. Seedlings had significantly higher growth rate and carbon isotope discrimination (∆13C) at the mid-elevation site than the high-elevation site. Provenances differed significantly in diameter, and ∆13C, but not in height growth rate for the first year after planting. Provenance variation in ∆13C suggests genetic variation in water use efficiency that may be useful for future evaluation of southwestern ponderosa pine seed sources for reforestation.

Stopover Site Fidelity by Tennessee Warblers at a Southern Appalachian High-elevation Site

2012 ◽  
Vol 124 (2) ◽  
pp. 366-370 ◽  
Author(s):  
David F. Vogt ◽  
Mark E. Hopey ◽  
G. Rad Mayfield ◽  
Eric C. Soehren ◽  
Laura M. Lewis ◽  
...  
Keyword(s):  
Site Fidelity ◽  
High Elevation ◽  
Stopover Site ◽  
Southern Appalachian ◽  
High Elevation Site

scholarly journals Insect herbivory facilitates the establishment of an invasive plant pathogen

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Martin M. Gossner ◽  
Ludwig Beenken ◽  
Kirstin Arend ◽  
Dominik Begerow ◽  
Derek Peršoh
Keyword(s):  
Invasive Plant ◽  
Pathogenic Fungus ◽  
Feeding Activity ◽  
Insect Herbivory ◽  
Forest Health ◽  
Mechanical Damage ◽  
Pathogenic Fungi ◽  
Fungal Colonization ◽  
Feeding Damage ◽  
The Impact

AbstractPlants can be severely affected by insect herbivores and phytopathogenic fungi, but interactions between these plant antagonists are poorly understood. We analysed the impact of feeding damage by the abundant herbivore Orchestes fagi on infection rates of beech (Fagus sylvatica) leaves with Petrakia liobae, an invasive plant pathogenic fungus. The fungus was not detected in hibernating beetles, indicating that O. fagi does not serve as vector for P. liobae, at least not between growing seasons. Abundance of the fungus in beech leaves increased with feeding damage of the beetle and this relationship was stronger for sun-exposed than for shaded leaves. A laboratory experiment revealed sun-exposed leaves to have thicker cell walls and to be more resistant to pathogen infection than shaded leaves. Mechanical damage significantly increased frequency and size of necroses in the sun, but not in shade leaves. Our findings indicate that feeding damage of adult beetles provides entry ports for fungal colonization by removal of physical barriers and thus promotes infection success by pathogenic fungi. Feeding activity by larvae probably provides additional nutrient sources or eases access to substrates for the necrotrophic fungus. Our study exemplifies that invasive pathogens may benefit from herbivore activity, which may challenge forest health in light of climate change.

scholarly journals The impact of four decades of annual nitrogen addition on dissolved organic matter in a boreal forest soil

2013 ◽  
Vol 10 (3) ◽  
pp. 1365-1377 ◽  
Author(s):  
M. O. Rappe-George ◽  
A. I. Gärdenäs ◽  
D. B. Kleja
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Soil Solution ◽  
Mineral Soil ◽  
Solution Concentration ◽  
Oxidative Enzymes ◽  
N Saturation ◽  
N Addition ◽  
Mineral N ◽  
The Impact

Abstract. Addition of mineral nitrogen (N) can alter the concentration and quality of dissolved organic matter (DOM) in forest soils. The aim of this study was to assess the effect of long-term mineral N addition on soil solution concentration of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in Stråsan experimental forest (Norway spruce) in central Sweden. N was added yearly at two levels of intensity and duration: the N1 treatment represented a lower intensity but a longer duration (43 yr) of N addition than the shorter N2 treatment (24 yr). N additions were terminated in the N2 treatment in 1991. The N treatments began in 1967 when the spruce stands were 9 yr old. Soil solution in the forest floor O, and soil mineral B, horizons were sampled during the growing seasons of 1995 and 2009. Tension and non-tension lysimeters were installed in the O horizon (n = 6), and tension lysimeters were installed in the underlying B horizon (n = 4): soil solution was sampled at two-week intervals. Although tree growth and O horizon carbon (C) and N stock increased in treatments N1 and N2, the concentration of DOC in O horizon leachates was similar in both N treatments and control. This suggests an inhibitory direct effect of N addition on O horizon DOC. Elevated DON and nitrate in O horizon leachates in the ongoing N1 treatment indicated a move towards N saturation. In B horizon leachates, the N1 treatment approximately doubled leachate concentrations of DOC and DON. DON returned to control levels, but DOC remained elevated in B horizon leachates in N2 plots nineteen years after termination of N addition. We propose three possible explanations for the increased DOC in mineral soil: (i) the result of decomposition of a larger amount of root litter, either directly producing DOC or (ii) indirectly via priming of old SOM, and/or (iii) a suppression of extracellular oxidative enzymes.

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