scholarly journals Recovery from fire affects spatial variability of nutrient availability in boreal aspen ecosystems

2018 ◽  
Author(s):  
Sanatan Das Gupta ◽  
M. Derek MacKenzie

Fire is a key driver of nutrient biogeochemistry in boreal ecosystems. Although a significant amount of research has been conducted to understand boreal fire ecology, it is still unclear how fire affects the spatial distribution of nutrients and what mechanisms are responsible for the post-fire recovery of spatial patterns. In this study, we examined spatial variability in soil nutrient bioavailability and related aboveground (AG) and belowground (BG) properties in three boreal aspen (Populus tremuloides Michx.) stands in northern Alberta at different stages of post-fire recovery. The studied sites include a 1-year old post fire stand (PF), a 9-year old stand at canopy closure (CC), and a 72-year old mature stand (MA). Ion exchange resin was used to measure nutrient bioavailability in-situ and was related to AG (vegetation and forest floor characteristics) and BG (soil microbial and chemical) properties. Significant spatial patterns were found in all three stands. PF stand had the greatest coarse scale spatial patterns (> 23 m) and availability of major macronutrients (N, P, and K). Shorter spatial range (5 to 10 m) of nutrient availability was observed in the stand with longest time since fire. Soil microbial activity was the strongest driver of nutrient availability in the PF stand, whereas contributions from aboveground variables such as understory vegetation, tree canopy cover, coarse woody debris (CWD), distance to nearest tree, and tree size was observed only in the CC and MA stands. The findings from the current study suggest that post-fire nutrient availability follows spatially predictable patterns, and confirm the hypothesis that stand replacing fire creates uniformity in nutrient availability and that the development of post-fire heterogeneity is a product of increasing ecosystem complexity.

2012 ◽  
Vol 42 (8) ◽  
pp. 1456-1466 ◽  
Author(s):  
Suzanne Brais ◽  
Pascal Drouin

Decaying wood contribution to the heterogeneity of forest soils could depend on tree species and wood decay stage. The study was conducted in an 85-year-old trembling aspen ( Populus tremuloides Michx.) – jack pine ( Pinus banksiana Lamb.) forest in northwestern Quebec, Canada. Trees, snags, logs, and forest floor originating from wood buried within the forest floor (lignic FF) and from fine litter (alignic FF) were inventoried in fifteen 400 m2 plots (nine jack pine and six trembling aspen). Chemical properties of alignic and lignic FF and logs were measured and relative nutrient availability in the mineral soil assessed under logs and under lignic and alignic FF using PRS probes. No significant differences between forest covers were found for the proportion of C and nutrients contained in deadwood (snags, logs, and lignic FF) relative to tree biomass plus necromass (deadwood plus alignic FF) content. Lignic FF was characterized by a higher C/N ratio and exchangeable acidity than alignic FF and its nutrient concentrations were between those of alignic FF and logs. Differences in wood characteristics may explain some of the differences in forest floor properties observed between trembling aspen and jack pine. Nutrient availability in the mineral soil was affected by the overlaying materials and could reflect differences in the dynamics of individual nutrients.


2013 ◽  
Vol 12 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Sarah K. Mincey ◽  
Mikaela Schmitt-Harsh ◽  
Richard Thurau

2021 ◽  
Vol 13 (5) ◽  
pp. 2640
Author(s):  
Muhammad Zubair ◽  
Akash Jamil ◽  
Syed Bilal Hussain ◽  
Ahsan Ul Haq ◽  
Ahmad Hussain ◽  
...  

The moist temperate forests in Northern Pakistan are home to a variety of flora and fauna that are pivotal in sustaining the livelihoods of the local communities. In these forests, distribution and richness of vegetation, especially that of medicinal plants, is rarely reported. In this study, we carried out a vegetation survey in District Balakot, located in Northeastern Pakistan, to characterize the diversity of medicinal plants under different canopies of coniferous forest. The experimental site was divided into three major categories (viz., closed canopy, open spaces, and partial tree cover). A sampling plot of 100 m2 was established on each site to measure species diversity, dominance, and evenness. To observe richness and abundance, the rarefaction and rank abundance curves were plotted. Results revealed that a total of 45 species representing 34 families were available in the study site. Medicinal plants were the most abundant (45%) followed by edible plants (26%). Tree canopy cover affected the overall growth of medicinal plants on the basis of abundance and richness. The site with partial canopy exhibited the highest diversity, dominance, and abundance compared to open spaces and closed canopy. These findings are instrumental in identifying the wealth of the medicinal floral diversity in the northeastern temperate forest of Balakot and the opportunity to sustain the livelihoods of local communities with the help of public/private partnership.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alexia Stokes ◽  
Guillermo Angeles ◽  
Fabien Anthelme ◽  
Eduardo Aranda-Delgado ◽  
Isabelle Barois ◽  
...  

Abstract Objectives Altitude integrates changes in environmental conditions that determine shifts in vegetation, including temperature, precipitation, solar radiation and edaphogenetic processes. In turn, vegetation alters soil biophysical properties through litter input, root growth, microbial and macrofaunal interactions. The belowground traits of plant communities modify soil processes in different ways, but it is not known how root traits influence soil biota at the community level. We collected data to investigate how elevation affects belowground community traits and soil microbial and faunal communities. This dataset comprises data from a temperate climate in France and a twin study was performed in a tropical zone in Mexico. Data description The paper describes soil physical and chemical properties, climatic variables, plant community composition and species abundance, plant community traits, soil microbial functional diversity and macrofaunal abundance and diversity. Data are provided for six elevations (1400–2400 m) ranging from montane forest to alpine prairie. We focused on soil biophysical properties beneath three dominant plant species that structure local vegetation. These data are useful for understanding how shifts in vegetation communities affect belowground processes, such as water infiltration, soil aggregation and carbon storage. Data will also help researchers understand how plant communities adjust to a changing climate/environment.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 433
Author(s):  
Xiaolan Huang ◽  
Weicheng Wu ◽  
Tingting Shen ◽  
Lifeng Xie ◽  
Yaozu Qin ◽  
...  

This research was focused on estimation of tree canopy cover (CC) by multiscale remote sensing in south China. The key aim is to establish the relationship between CC and woody NDVI (NDVIW) or to build a CC-NDVIW model taking northeast Jiangxi as an example. Based on field CC measurements, this research used Google Earth as a complementary source to measure CC. In total, 63 sample plots of CC were created, among which 45 were applied for modeling and the remaining 18 were employed for verification. In order to ascertain the ratio R of NDVIW to the satellite observed NDVI, a 20-year time-series MODIS NDVI dataset was utilized for decomposition to obtain the NDVIW component, and then the ratio R was calculated with the equation R = (NDVIW/NDVI) *100%, respectively, for forest (CC >60%), medium woodland (CC = 25–60%) and sparse woodland (CC 1–25%). Landsat TM and OLI images that had been orthorectified by the provider USGS were atmospherically corrected using the COST model and used to derive NDVIL. R was multiplied for the NDVIL image to extract the woody NDVI (NDVIWL) from Landsat data for each of these plots. The 45 plots of CC data were linearly fitted to the NDVIWL, and a model with CC = 103.843 NDVIW + 6.157 (R2 = 0.881) was obtained. This equation was applied to predict CC at the 18 verification plots and a good agreement was found (R2 = 0.897). This validated CC-NDVIW model was further applied to the woody NDVI of forest, medium woodland and sparse woodland derived from Landsat data for regional CC estimation. An independent group of 24 measured plots was utilized for validation of the results, and an accuracy of 83.0% was obtained. Thence, the developed model has high predictivity and is suitable for large-scale estimation of CC using high-resolution data.


2021 ◽  
Vol 51 ◽  
Author(s):  
Diogo Neia Eberhardt ◽  
Robélio Leandro Marchão ◽  
Pedro Rodolfo Siqueira Vendrame ◽  
Marc Corbeels ◽  
Osvaldo Guedes Filho ◽  
...  

ABSTRACT Tropical Savannas cover an area of approximately 1.9 billion hectares around the word and are subject to regular fires every 1 to 4 years. This study aimed to evaluate the influence of burning windrow wood from Cerrado (Brazilian Savanna) deforestation on the spatial variability of soil chemical properties, in the field. The data were analysed by using geostatistical methods. The semivariograms for pH(H2O), pH(CaCl2), Ca, Mg and K were calculated according to spherical models, whereas the phosphorus showed a nugget effect. The cross semi-variograms showed correlations between pH(H2O) and pH(CaCl2) with other variables with spatial dependence (exchangeable Ca and Mg and available K). The spatial variability maps for the pH(H2O), pH(CaCl2), Ca, Mg and K concentrations also showed similar patterns of spatial variability, indicating that burning the vegetation after deforestation caused a well-defined spatial arrangement. Even after 20 years of use with agriculture, the spatial distribution of pH(H2O), pH(CaCl2), Ca, Mg and available K was affected by the wood windrow burning that took place during the initial deforestation.


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