Quantifying the influence of individual trees on slope stability at landscape scale

2021 ◽  
Vol 286 ◽  
pp. 112194
Author(s):  
Raphael I. Spiekermann ◽  
Sam McColl ◽  
Ian Fuller ◽  
John Dymond ◽  
Lucy Burkitt ◽  
...  
Keyword(s):  
Slope Stability ◽  
Landscape Scale ◽  
Individual Trees

Inferring the effect of individual trees on slope stability in New Zealand’s pastoral hill country

2021 ◽  
Author(s):  
Raphael Spiekermann ◽  
Sam McColl ◽  
Ian Fuller ◽  
John Dymond ◽  
Lucy Burkitt ◽  
...  
Keyword(s):  
New Zealand ◽  
Slope Stability ◽  
Landslide Susceptibility ◽  
Soil Conservation ◽  
Spatially Explicit ◽  
Sustainable Land Management ◽  
Root Reinforcement ◽  
Sediment Control ◽  
Hill Country ◽  
Individual Trees

<p>Silvopastoralism in New Zealand’s highly erodible hill country is an important form of erosion and sediment control. Despite a long history in improving sustainable land management and soil conservation since the enactment of the Soil Conservation and Rivers Control Act 1941, there has been little quantitative work to establish the effectiveness of space-planted trees in reducing shallow landslide erosion at farm to landscape scales. This is largely due to the lack of spatially explicit data on individual trees and their influence on slope stability. Therefore, it is difficult to determine the extent to which plantings have targeted slopes susceptible to landslide erosion. Furthermore, root data collection for multiple species and age classes is very time-consuming and costly, which limits the development of root reinforcement models for different species and partly explains the paucity of quantitative data on the effectiveness of space-planted trees.</p><p>We present an empirical approach that aims to fill the gap in scale between 1) physical models that integrated root reinforcement data of individual trees into slope stability models and 2) landslide susceptibility modelling at regional scale using land cover data. First, we delineate individual tree crowns (ITCs) at landscape scale and classify into dominant species classes found in New Zealand’s pastoral hill country. The resulting rural tree species classification achieved an overall accuracy of 92.6% based on 9,200 samples that were collected from two farms within the study area. We then present a spatially explicit tree influence model for each species class developed by means of inductive inference. The tree influence models represent the combined hydrological and mechanical influence of trees on slopes, which is inferred through the spatial relationship between individual trees and landslide erosion. The resulting tree influence models largely agree with the shape and distribution of existing physical root reinforcement models.</p><p>Of exotic species that were planted for erosion and sediment control, poplars (Populus spp.) and willows (Salix spp.) make up 51% (109,000 trees) in pastoral hill country at a mean density of 3.2 trees/ha. This large number of poplars and willows reflects the efforts made by landowners and soil conservators over several decades to mitigate erosion processes and adopt more sustainable land management practices. In line with previous studies, poplars and willows have the greatest contribution to slope stability with an average maximum effective distance of 20 m. Yet, native kānuka (Kunzea spp.) is the most abundant woody vegetation species in pastoral hill country within the study area, with an average of 24.1 stems per ha (sph), providing an important soil conservation function. A large proportion (56% or 212.5 km<sup>2</sup>) of pastoral hill-country in the study area remains untreated, i.e. has no added soil shear strength due to the presence of trees. The tree influence models presented in this study can be integrated into landslide susceptibility modelling in silvopastoral/agroforestry landscapes to both quantify the reduction in landslide susceptibility achieved and support targeted erosion and sediment mitigation plans.</p>

scholarly journals Tree-, stand- and site-specific controls on landscape-scale patterns of transpiration

2017 ◽  
Author(s):  
Sibylle K. Hassler ◽  
Markus Weiler ◽  
Theresa Blume
Keyword(s):  
Spatial Variability ◽  
Sap Flow ◽  
Temporal Dynamics ◽  
Stand Density ◽  
Landscape Scale ◽  
Tree Stand ◽  
Site Specific ◽  
As Species ◽  
Individual Trees ◽  
Transfer Models

Abstract. Transpiration is a key process in the hydrological cycle and a sound understanding and quantification of transpiration and its spatial variability is essential for management decisions as well as for improving the parameterisation of hydrological and soil–vegetation–atmosphere transfer models. For individual trees, transpiration is commonly estimated by measuring sap flow. Besides evaporative demand and water availability, tree-specific characteristics such as species, size or social status control sap flow amounts of individual trees. Within forest stands, properties such as species composition, basal area or stand density additionally affect sap flow, for example via competition mechanisms. Finally, sap flow patterns might also be influenced by landscape-scale characteristics such as geology, slope position or aspect because they affect water and energy availability; however, little is known about the dynamic interplay of these controls. We studied the relative importance of various tree-, stand- and site-specific characteristics with multiple linear regression models to explain the variability of sap velocity measurements in 61 beech and oak trees, located at 24 sites spread over a 290 km2-catchment in Luxembourg. For each of 132 consecutive days of the growing season of 2014 we modelled the daily sap velocities of these 61 trees and determined the importance of the different predictors. Results indicate that a combination of tree-, stand- and site-specific factors controls sap velocity patterns in the landscape, namely tree species, tree diameter, the stand density, geology and aspect. Compared to these predictors, spatial variability of atmospheric demand and soil moisture explains only a small fraction of the variability in the daily datasets. However, the temporal dynamics of the explanatory power of the tree-specific characteristics, especially species, are correlated to the temporal dynamics of potential evaporation. Thus, transpiration estimates at the landscape scale would benefit from not only considering hydro-meteorological drivers, but also including tree, stand and site characteristics in order to improve the spatial representation of transpiration for hydrological and soil–vegetation–atmosphere transfer models.

scholarly journals Tree-, stand- and site-specific controls on landscape-scale patterns of transpiration

2018 ◽  
Vol 22 (1) ◽  
pp. 13-30 ◽  
Author(s):  
Sibylle Kathrin Hassler ◽  
Markus Weiler ◽  
Theresa Blume
Keyword(s):  
Spatial Variability ◽  
Sap Flow ◽  
Temporal Dynamics ◽  
Flow Patterns ◽  
Landscape Scale ◽  
Tree Stand ◽  
Site Specific ◽  
As Species ◽  
Individual Trees ◽  
Transfer Models

Abstract. Transpiration is a key process in the hydrological cycle, and a sound understanding and quantification of transpiration and its spatial variability is essential for management decisions as well as for improving the parameterisation and evaluation of hydrological and soil–vegetation–atmosphere transfer models. For individual trees, transpiration is commonly estimated by measuring sap flow. Besides evaporative demand and water availability, tree-specific characteristics such as species, size or social status control sap flow amounts of individual trees. Within forest stands, properties such as species composition, basal area or stand density additionally affect sap flow, for example via competition mechanisms. Finally, sap flow patterns might also be influenced by landscape-scale characteristics such as geology and soils, slope position or aspect because they affect water and energy availability; however, little is known about the dynamic interplay of these controls. We studied the relative importance of various tree-, stand- and site-specific characteristics with multiple linear regression models to explain the variability of sap velocity measurements in 61 beech and oak trees, located at 24 sites across a 290 km2 catchment in Luxembourg. For each of 132 consecutive days of the growing season of 2014 we modelled the daily sap velocity and derived sap flow patterns of these 61 trees, and we determined the importance of the different controls. Results indicate that a combination of mainly tree- and site-specific factors controls sap velocity patterns in the landscape, namely tree species, tree diameter, geology and aspect. For sap flow we included only the stand- and site-specific predictors in the models to ensure variable independence. Of those, geology and aspect were most important. Compared to these predictors, spatial variability of atmospheric demand and soil moisture explains only a small fraction of the variability in the daily datasets. However, the temporal dynamics of the explanatory power of the tree-specific characteristics, especially species, are correlated to the temporal dynamics of potential evaporation. We conclude that transpiration estimates on the landscape scale would benefit from not only consideration of hydro-meteorological drivers, but also tree, stand and site characteristics in order to improve the spatial and temporal representation of transpiration for hydrological and soil–vegetation–atmosphere transfer models.

The stability and collapse of lava domes: insight from UAS-derived 4D structure and slope stability models

2020 ◽  
Author(s):  
Brett Carr ◽  
Einat Lev ◽  
Loÿc Vanderkluysen ◽  
Danielle Moyer ◽  
Gayatri Marliyani ◽  
...  
Keyword(s):  
Slope Stability ◽  
Lava Domes ◽  
The Stability

Resistance of some plum cultivars and individual trees to Plum Pox (Sharka) virus

Agronomie ◽  
1981 ◽  
Vol 1 (8) ◽  
pp. 617-622 ◽  
Author(s):  
D. ŠUTI ◽  
M. RANKOVIĆ
Keyword(s):  
Individual Trees ◽  
Sharka Virus

ANALISIS KESTABILAN LERENG DINDING AKHIR DI PIT BARATLAUT PADA PENAMBANGAN BATUBARA DI PT. PUTERA BARA MITRA , KECAMATAN MENTEWE, KALIMANTAN SELATAN

KURVATEK ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21-34
Author(s):  
Untung Wahyudi ◽  
Excelsior T P ◽  
Luthfi Wahyudi
Keyword(s):  
Slope Stability ◽  
Mining Operation ◽  
Subsurface Water ◽  
Mining System ◽  
Mine Site ◽  
Analysis And Design ◽  
The Stability ◽  
End Wall ◽  
Wall Slope ◽  
Mining Slope

PT. Putera Bara Mitra used open mining system for mining operation, Yet the completion of study on the end wall slope stability that  undertaken by geotechnical PT. Putera Bara Mitra in Northwest Pit and the occured a failure in the low wall on the 1st June 2012 led to the need for analysis and design the overall slope at the mine site. To analyze and design the overall slope, used value of the recommended minimum safety. The value was based on company for single slope SF ≥ 1.2 and SF ≥ 1.3 for overall slope. The calculation used Bichop method with the help of software slide v 5.0. Geometry improvements was done at the low slopes that originally single wall with a 30 m bench height and a slope 70° with SF = 0.781, into 4 levels with SF = 1.305. The analysis explained the factors that affect the stability of the low wall included the mining slope geometry, unfavorable drainase system, material stockpiles and seismicity factors. It was necessary to do prevention efforts to maintain the stability of the slope included the redesign to slope geometry, handling surface and subsurface water in a way to control slopes draining groundwater, vegetation stabilization using and monitoring slope using Total Station with Prism and Crackmeter to determine the movement of cracks visible on the surface. 

Landscape-Scale Restoration of the Longleaf Pine Ecosystem

1998 ◽  
Vol 16 (1) ◽  
pp. 41-45
Author(s):  
Rhett Johnson ◽  
Dean Gjerstad
Keyword(s):  
Longleaf Pine ◽  
Landscape Scale
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