scholarly journals Comparison of Satellite and Drone-Based Images at Two Spatial Scales to Evaluate Vegetation Regeneration after Post-Fire Treatments in a Mediterranean Forest

2021 ◽  
Vol 11 (12) ◽  
pp. 5423
Author(s):  
Jose Luis Martinez ◽  
Manuel Esteban Lucas-Borja ◽  
Pedro Antonio Plaza-Alvarez ◽  
Pietro Denisi ◽  
Miguel Angel Moreno ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Spatial Scales ◽  
Soil Surface ◽  
Plant Biodiversity ◽  
Mediterranean Forests ◽  
Experimental Conditions ◽  
Vegetation Growth ◽  
Surface Conditions ◽  
Vegetation Regeneration ◽  
Forest Managers

The evaluation of vegetation cover after post-fire treatments of burned lands is important for forest managers to restore soil quality and plant biodiversity in burned ecosystems. Unfortunately, this evaluation may be time consuming and expensive, requiring much fieldwork for surveys. The use of remote sensing, which makes these evaluation activities quicker and easier, have rarely been carried out in the Mediterranean forests, subjected to wildfire and post-fire stabilization techniques. To fill this gap, this study evaluates the feasibility of satellite (using LANDSAT8 images) and drone surveys to evaluate changes in vegetation cover and composition after wildfire and two hillslope stabilization treatments (log erosion barriers, LEBs, and contour-felled log debris, CFDs) in a forest of Central Eastern Spain. Surveys by drone were able to detect the variability of vegetation cover among burned and unburned areas through the Visible Atmospherically Resistant Index (VARI), but gave unrealistic results when the effectiveness of a post-fire treatment must be evaluated. LANDSAT8 images may be instead misleading to evaluate the changes in land cover after wildfire and post-fire treatments, due to the lack of correlation between VARI and vegetation cover. The spatial analysis has shown that: (i) the post-fire restoration strategy of landscape managers that have prioritized steeper slopes for treatments was successful; (ii) vegetation growth, at least in the experimental conditions, played a limited influence on soil surface conditions, since no significant increases in terrain roughness were detected in treated areas.

scholarly journals Competition-free gaps are essential for the germination and recruitment of alpine species along an elevation gradient in the European Alps

Alpine Botany ◽  
2021 ◽  
Author(s):  
Vera Margreiter ◽  
Janette Walde ◽  
Brigitta Erschbamer
Keyword(s):  
Vegetation Cover ◽  
Seedling Recruitment ◽  
Environmental Control ◽  
Elevation Gradient ◽  
European Alps ◽  
Plant Interactions ◽  
Experimental Conditions ◽  
Positive Effects ◽  
Seed Sowing ◽  
Plant Plant

AbstractSeed germination and seedling recruitment are key processes in the life cycle of plants. They enable populations to grow, migrate, or persist. Both processes are under environmental control and influenced by site conditions and plant–plant interactions. Here, we present the results of a seed-sowing experiment performed along an elevation gradient (2000–2900 m a.s.l.) in the European eastern Alps. We monitored the germination of seeds and seedling recruitment for 2 years. Three effects were investigated: effects of sites and home sites (seed origin), effects of gaps, and plant–plant interactions. Seeds of eight species originating from two home sites were transplanted to four sites (home site and ± in elevation). Seed sowing was performed in experimentally created gaps. These gap types (‘gap + roots’, ‘neighbor + roots’, and ‘no-comp’) provided different plant–plant interactions and competition intensities. We observed decreasing germination with increasing elevation, independent of the species home sites. Competition-released gaps favored recruitment, pointing out the important role of belowground competition and soil components in recruitment. In gaps with one neighboring species, neutral plant–plant interactions occurred (with one exception). However, considering the relative vegetation cover of each experimental site, high vegetation cover resulted in positive effects on recruitment at higher sites and neutral effects at lower sites. All tested species showed intraspecific variability when responding to the experimental conditions. We discuss our findings considering novel site and climatic conditions.

scholarly journals Soil-vegetation relationships in Mediterranean forests after fire

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Víctor Fernández-García ◽  
Elena Marcos ◽  
Sara Huerta ◽  
Leonor Calvo
Keyword(s):  
Soil Properties ◽  
Mediterranean Ecosystems ◽  
Fire Effects ◽  
Mediterranean Forests ◽  
Vegetation Growth ◽  
Burned Areas ◽  
Vegetation Height ◽  
P Content ◽  
Study Sites ◽  
Soil Status

Abstract Background Wildfires are one of the major environmental concerns in Mediterranean ecosystems. Thus, many studies have addressed wildfire impacts on soil and vegetation in Mediterranean forests, but the linkages between these ecosystem compartments after fire are not well understood. The aim of this work is to analyze soil-vegetation relationships in Mediterranean burned forests as well as the consistency of these relationships among forests with different environmental conditions, at different times after fire, and among vegetation with different functional traits. Results Our results indicate that study site conditions play an important role in mediating soil-vegetation relationships. Likewise, we found that the nature of soil-vegetation relationships may vary over time as fire effects are less dominant in both ecosystem compartments. Despite this, we detected several common soil-vegetation relationships among study sites and times after fire. For instance, our results revealed that available P content and stoichiometry (C:P and N:P) were closely linked to vegetation growth, and particularly to the growth of trees. We found that enzymatic activities and microbial biomass were inversely related to vegetation growth rates, whereas the specific activities of soil enzymes were higher in the areas with more vegetation height and cover. Likewise, our results suggest that resprouters may influence soil properties more than seeders, the growth of seeders being more dependent on soil status. Conclusions We provide pioneer insights into how vegetation is influenced by soil, and vice-versa, in Mediterranean burned areas. Our results reflect variability in soil-vegetation relationships among study sites and time after fire, but consistent patterns between soil properties and vegetation were also detected. Our research is highly relevant to advance in forest science and could be useful to achieve efficient post-fire management.

scholarly journals Local- and Landscape-Level Variables Related to Poweshiek Skipperling Presence in Michigan Prairie Fens

2019 ◽  
Vol 10 (2) ◽  
pp. 375-390 ◽  
Author(s):  
Clint D. Pogue ◽  
Michael J. Monfils ◽  
David L. Cuthrell ◽  
Rachel A. Hackett ◽  
Riley A. Zionce ◽  
...  
Keyword(s):  
Host Plants ◽  
Spatial Scales ◽  
Schizachyrium Scoparium ◽  
Suitable Habitat ◽  
Plant Biodiversity ◽  
Biologically Relevant ◽  
System Integrity ◽  
Larval Host ◽  
Weedy Species ◽  
Larval Host Plants

Abstract The Poweshiek skipperling Oarisma poweshiek, Lepidoptera: Hesperiidae is a historically common prairie butterfly with a range extending throughout prairie systems of the upper midwestern United States and southern Manitoba, Canada. Rapid, range-wide declines have reduced the number of verified Poweshiek skipperling locations to one in Manitoba prairie, one in Wisconsin prairie, and four in prairie fens in Michigan. Our objective was to investigate parameter suites with the potential to be biologically relevant to Poweshiek skipperling occupancy with the goal of informing conservation efforts. At 18 prairie fens categorized as occupied (n = 9) or unoccupied (n = 9), we collected information on plant biodiversity, water chemistry, soil chemistry, site geometry, and surrounding current and historical land cover at three spatial scales. To address the complexity of these systems, we used multiresponse permutation procedures and nonmetric multidimensional scaling to explore associations between variable groups thought to be relevant to Poweshiek skipperling (conditions for suspected larval host plants, system integrity, and agricultural influence) and occupancy categories. We used indicator species analysis to understand the relationships between plant biodiversity and Poweshiek skipperling occupancy at whole- and intrafen scales. Multiresponse permutation procedures analysis suggested that conditions for suspected larval host plants differed between occupied and unoccupied prairie fens. At the whole-fen scale, we identified 14 plant species associated with Poweshiek-occupied sites, including two purported larval host plants, Muhlenbergia richardsonis and Schizachyrium scoparium. At the intrafen scale, we identified 52 species associated with unoccupied Poweshiek sites, including many weedy species and those tolerant of inundated conditions. Our results can inform the evaluation of potentially suitable habitat for introduction and reintroduction efforts.

scholarly journals Regional climate and local-scale biotic acceptance explain native–exotic richness relationships in Australian annual plant communities

2018 ◽  
Vol 285 (1886) ◽  
pp. 20181328 ◽  
Author(s):  
Isaac. R. Towers ◽  
John. M. Dwyer
Keyword(s):  
Exotic Species ◽  
Structural Equation ◽  
Spatial Scales ◽  
Regional Climate ◽  
Soil Surface ◽  
Equation Model ◽  
Annual Plant ◽  
Regional Temperature ◽  
Neighbourhood Scale ◽  
Biotic Acceptance

Native and exotic species richness is expected to be negatively related at small spatial scales where individuals interact, and positive at larger spatial scales as a greater variety of habitats are sampled. However, a range of native–exotic richness relationships (NERRs) have been reported, including positive at small scales and negative at larger scales. We present a hierarchical metacommunity framework to explain how contrasting NERRs may emerge across scales and study systems, and then apply this framework to NERRs in an invaded winter annual plant system in southwest Western Australia. We analysed NERRs at increasing spatial scales from neighbourhoods (0.09 m 2 ) to communities (225 m 2 ) to metacommunities (greater than 10 ha) within a multilevel structural equation model. In contrast to many previous studies, native and exotic richness were positively related at the neighbourhood scale and were not significantly associated at larger scales. Heterogeneity in soil surface properties was weakly, but positively, associated with native and exotic richness at the community scale. Metacommunity exotic richness increased strongly with regional temperature and moisture availability, but relationships for native richness were negative and much weaker. Thus, we show that neutral NERRs can emerge at larger scales owing to differential climatic filtering of native and exotic species pools.

Measurement of soil erosion on different spatial scales with vegetation cover of caatinga in the northeast of Brazil

2012 ◽  
Author(s):  
Julio Cesar Neves dos Santos ◽  
Eunice Maia de Andrade ◽  
Helba Araújo de Queiroz Palácio ◽  
José Ribeiro de Araújo Neto ◽  
José Ailton da Silva Filho
Keyword(s):  
Soil Erosion ◽  
Vegetation Cover ◽  
Spatial Scales

scholarly journals Vascular Plant Diversity in Burned and Unburned Alvar Woodland: More Evidence of the Importance of Disturbance to Biodiversity and Conservation

2009 ◽  
Vol 123 (3) ◽  
pp. 240 ◽  
Author(s):  
Paul Catling
Keyword(s):  
Plant Diversity ◽  
Rare Species ◽  
Vegetation Cover ◽  
Vascular Plant ◽  
Plant Biodiversity ◽  
Vascular Plant Diversity ◽  
The Creation

Vascular plant biodiversity was compared in an unburned semi-open alvar woodland dominated by conifers and an equivalent woodland that had burned nine years previously and had developed into a long-lasting successional shrubland. The comparison, based on 30 quadrats 1 m2 at each of two sites, revealed less than 25% similarity in the vegetation cover of the two sites. The successional alvar shrubland that developed following fire had twice as many species and more regionally rare species than the corresponding woodland site. The shrubland also had higher values for various biodiversity measures that take heterogeneity and evenness into account. These data provide additional evidence for the importance of fire and disturbance in the creation of successional habitat upon which biodiversity depends. A cautious use of fire in management of alvars is supported.

Herbicide Performance and Soil Surface Conditions

Weed Research ◽  
1971 ◽  
Vol 11 (1) ◽  
pp. 69-73 ◽  
Author(s):  
H. A. ROBERTS and ◽  
R. T. HEWSON
Keyword(s):  
Soil Surface ◽  
Surface Conditions

Grazing Gradients in Central Australian Rangelands: Ground Verification of Remote Sensing-Based Approaches.

1993 ◽  
Vol 15 (2) ◽  
pp. 217 ◽  
Author(s):  
GN Bastin ◽  
AD Sparrow ◽  
G Pearce
Keyword(s):  
Satellite Data ◽  
Vegetation Cover ◽  
Field Data ◽  
Graphical Representation ◽  
Woody Species ◽  
Soil Surface ◽  
Grazing Pressure ◽  
Remotely Sensed Data ◽  
Suitable Technique ◽  
Grazing Behaviour

Remotely-sensed data collected by satellites have been proposed for investigating grazing effects across the large paddocks of arid Australia. These data are used to compute indices of vegetation cover which are then analysed with reference to patterns of grazing behaviour around watering points. Grazing pressure typically increases as water is approached, resulting in a decrease in herbage cover. This pattern of cover change is called a grazing gradient. The change in these gradients from a dry to wet period forms the basis for assessing land degradation as described in an accompanying paper. This study demonstrates that grazing gradients do exist, that they can be detected with field-based methods of data collection, and that there is close correspondence between ground data and indices of vegetation cover obtained from contemporary Landsat Multispectral Scanner satellite data. Field data representing aerial cover of the herbage and woody species layers were collected along transects radiating away from water at two sites grazed by cattle in central Australia. Graphical representation of the litter and herbage components demonstrate that gradients of decreasing cover attributable to increasing grazing pressure occur along all, or sections, of each transect. Highly significant correlations exist between the field data and satellite indices of vegetation cover. Localised shrub increase and patches of recent erosion obscured trends of increasing cover with distance from water on parts of some transects. Soil surface state (describing past erosion) was a significant covariate of cover change at one site. Our ability to characterise gradients of increasing vegetation cover with distance from water using both field and satellite data should mean that the grazing gradient method, when used with satellite data, is a suitable technique for assessing the extent of landscape recovery following good rainfall.

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