Removing woody vegetation has little effect on conduit flow recharge

Ecohydrology ◽  
2012 ◽  
Vol 6 (3) ◽  
pp. 435-443 ◽  
Author(s):  
Roberto A. Bazan ◽  
Bradford P. Wilcox ◽  
Clyde Munster ◽  
Marcus Gary
Keyword(s):  
Woody Vegetation ◽  
Conduit Flow

scholarly journals Classification of Post-Fire Responses of Woody Plants to include Pyrophobic Communities

Fire ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 15 ◽  
Author(s):  
Lynda D. Prior ◽  
David M. J. S. Bowman
Keyword(s):  
Woody Plants ◽  
Seed Banks ◽  
Classification Systems ◽  
Woody Vegetation ◽  
General Category ◽  
Conifer Species ◽  
Soil Seed Banks ◽  
Obligate Seeder ◽  
In Fire

Developing standardised classification of post-fire responses is essential for globally consistent comparisons of woody vegetation communities. Existing classification systems are based on responses of species growing in fire-prone environments. To accommodate species that occur in rarely burnt environments, we have suggested some important points of clarification to earlier schemes categorizing post-fire responses. We have illustrated this approach using several Australasian conifer species as examples of pyrophobic species. In particular, we suggest using the term “obligate seeder” for the general category of plants that rely on seed to reproduce, and qualifying this to “post-fire obligate seeder” for the narrower category of species with populations that recover from canopy fire only by seeding; the species are typically fire-cued, with large aerial or soil seed banks that germinate profusely following a fire, and grow and reproduce rapidly in order to renew the seed bank before the next fire.

scholarly journals Woody Vegetation Cover, Attrition, and Patch Metrics over Eight Decades in Central Texas, United States

2021 ◽  
Vol 78 ◽  
pp. 54-66
Author(s):  
Edward C. Rhodes ◽  
Jay P. Angerer ◽  
William E. Fox ◽  
Jason R. McAlister
Keyword(s):  
United States ◽  
Vegetation Cover ◽  
Woody Vegetation ◽  
Central Texas

scholarly journals The Effects of Roadside Woody Vegetation on the Surface Temperature of Cycle Paths

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 483
Author(s):  
Nikola Žižlavská ◽  
Tomáš Mikita ◽  
Zdeněk Patočka
Keyword(s):  
Solar Radiation ◽  
Surface Temperature ◽  
Well Being ◽  
Road Surface ◽  
Woody Vegetation ◽  
Surface Model ◽  
Main Hypothesis ◽  
Roadside Vegetation ◽  
Different Types ◽  
Aerial Vehicle

The article is on the effects of woody vegetation growing on the roadside on the temperature of the surface of cycle paths. The main hypothesis of the study is that vegetation has the effect of lowering the temperature of the surroundings in its shadow and thus improves the comfort of users of cycle paths in the summer months. The second hypothesis is to find out which type of road surface is most suitable for the thermal well-being of users. This goal was achieved by measuring the temperature of selected locations on cycle paths with different types of construction surfaces with nearby woody vegetation using a contactless thermometer over several days at regular intervals. The positions of the selected locations were measured using GNSS and the whole locality of interest was photographed using an unmanned aerial vehicle (UAV), or drone, and subsequently a digital surface model (DSM) of the area was created using a Structure from Motion (SfM) algorithm. This model served for the calculation of incident solar radiation during the selected days using the Solar Area Graphics tool with ArcGIS software. Subsequently, the effect of the shade of the surrounding vegetation on the temperature during the day was analysed and statistically evaluated. The results are presented in many graphs and their interpretation used to evaluate the effects of nearby woody vegetation and the type of road surface on the surrounding air temperature and the comfort of users of these routes. The results demonstrate the benefits of using UAVs for the purpose of modelling the course of solar radiation during the day, showing the effect of roadside vegetation on reducing the surface temperature of the earth’s surface and thus confirming the need for planting and maintaining such vegetation.

scholarly journals Spatially explicit statistical modeling of random and systematic land cover transitions in the main grassland plain of Nech Sar National Park, Ethiopia

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Kiros Tsegay Deribew
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Statistical Modeling ◽  
National Park ◽  
Spatial Extent ◽  
Aerial Photographs ◽  
Woody Vegetation ◽  
Spatially Explicit ◽  
Strong Signal ◽  
The Past

AbstractThe main grassland plain of Nech Sar National Park (NSNP) is a federally managed protected area in Ethiopia designated to protect endemic and endangered species. However, like other national parks in Ethiopia, the park has experienced significant land cover change over the past few decades. Indeed, the livelihoods of local populations in such developing countries are entirely dependent upon natural resources and, as a result, both direct and indirect anthropogenic pressures have been placed on natural parks. While previous research has looked at land cover change in the region, these studies have not been spatially explicit and, as a result, knowledge gaps in identifying systematic transitions continue to exist. This study seeks to quantify the spatial extent and land cover change trends in NSNP, identify the strong signal transitions, and identify and quantify the location of determinants of change. To this end, the author classifies panchromatic aerial photographs in 1986, multispectral SPOT imagery in 2005, and Sentinel imagery in 2019. The spatial extent and trends of land cover change analysis between these time periods were conducted. The strong signal transitions were systematically identified and quantified. Then, the basic driving forces of the change were identified. The locations of these transitions were also identified and quantified using the spatially explicit statistical model. The analysis revealed that over the past three decades (1986–2019), nearly 52% of the study area experienced clear landscape change, out of which the net change and swap change attributed to 39% and 13%, respectively. The conversion of woody vegetation to grassland (~ 5%), subsequently grassland-to-open-overgrazed land (28.26%), and restoration of woody vegetation (0.76%) and grassland (0.72%) from riverine forest and open-overgrazed land, respectively, were found to be the fully systematic transitions whereas the rest transitions were recorded either partly systematic or random transitions. The location of these most systematic land cover transitions identified through the spatially explicit statistical modeling showed drivers due to biophysical conditions, accessibility, and urban/market expansions, coupled with successive government policies for biodiversity management, geo-politics, demographic, and socioeconomic factors. These findings provide important insights into biodiversity loss, land degradation, and ecosystem disruption. Therefore, the model for predicted probability generally suggests a 0.75 km and 0.72 km buffers which are likely to protect forest and grassland from conversion to grassland and open-overgrazed land, respectively.

scholarly journals The Effects of Exchange Flow on the Karst Spring Hydrograph under the Different Flow Regimes: A Synthetic Modeling Approach

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1189
Author(s):  
Malihe Shirafkan ◽  
Zargham Mohammadi ◽  
Vianney Sivelle ◽  
David Labat
Keyword(s):  
Flow Regime ◽  
Spring Discharge ◽  
Exchange Flow ◽  
Flow Conditions ◽  
Spring Hydrograph ◽  
Conduit Flow ◽  
Discharge Fluctuations ◽  
Recession Coefficient ◽  
The Matrix ◽  
Synthetic Modeling

In this study, a synthetic modeling approach is proposed to quantify the effect of the amount and direction of the exchange flow on the karstic spring discharge fluctuations under different hydrologic conditions corresponding to high and low flow conditions. We hypothesis that the spring discharge fluctuations constitute a valuable proxy to understand the internal processes of the karst system. An ensemble of spring hydrographs was synthetically produced to highlight the effect of exchange flow by exploring the plausible range of variability of coefficients of exchange flow, conduit diameter, and matrix hydraulic conductivity. Moreover, the change of the rate of point recharge through the karst conduit allows for the quantifying of the sensibility of the spring hydrograph to the directions of exchange flow. We show that increasing the point recharge lies to a remarkable linear recession coefficient (β) as an indication of the conduit flow regime. However, a reduction in and/or lack of the point recharge caused the recession coefficient to change to exponential (α) due to the dominant effect of the matrix restrained flow regime and/or conduit-influenced flow regime. The simulations highlight that the exchange flow process from the conduit to the matrix occurred in a short period and over a restricted part of the conduit flow regime (CFR). Conversely, the exchange flow dumped from the matrix to the conduit occurs as a long-term process. A conceptual model is introduced to compare spring hydrographs’ characteristics (i.e., the peak discharge, the volume of baseflow, and the slope of the recession curve) under the various flow conditions with the directions of the exchange flow between the conduit and the matrix.

Nitrous oxide production in two forested watersheds exhibiting symptoms of nitrogen saturation

1998 ◽  
Vol 28 (11) ◽  
pp. 1723-1732 ◽  
Author(s):  
William T Peterjohn ◽  
Richard J McGervey ◽  
Alan J Sexstone ◽  
Martin J Christ ◽  
Cassie J Foster ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Saturation ◽  
N Cycling ◽  
Woody Vegetation ◽  
N Saturation ◽  
Relative Importance ◽  
Forested Watersheds ◽  
Total N ◽  
Nitrous Oxide Production ◽  
Poorly Drained Soils

A major concern about N saturation is that it may increase the production of a strong greenhouse gas, nitrous oxide (N2O). We measured N2O production in two forested watersheds, a young, fertilized forest (WS 3) and an older, unfertilized forest (WS 4), to (i) assess the importance of N2O production in forests showing symptoms of N saturation; (ii) estimate the contribution of chemoautrophic nitrification to total N2O production; and (iii) examine the relative importance of factors that may control N2O production. During the study period, mean monthly rates of N2O production (3.41-11.42 µ N ·m-2·h-1) were consistent with measurements from other well-drained forest soils but were much lower than measurements from N-rich sites with poorly drained soils. Chemoautotrophic nitrification was important in both watersheds, accounting for 60% (WS 3) and 40% (WS 4) of total N2O production. In WS 3, N2O production was enhanced by additions of CaCO3 and may be constrained by low soil pH. In WS 4, N2O production on south-facing slopes was exceptionally low, constrained by low NO3 availability, and associated with a distinct assemblage of woody vegetation. From this observation, we hypothesize that differences in vegetation can influence N cycling rates and susceptibility to N saturation.

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