Remote Sensing of Forest Condition in Tolerant Hardwoods: An Examination of Spatial Scale, Structure and Function

2001 ◽  
Vol 27 (3) ◽  
pp. 232-246 ◽  
Author(s):  
P.H. Sampson ◽  
P.M. Treitz ◽  
G.H. Mohammed
Keyword(s):  
Remote Sensing ◽  
Spatial Scale ◽  
Structure And Function ◽  
Scale Structure ◽  
Forest Condition ◽  
And Function

scholarly journals Mapping Spatial Variations of Structure and Function Parameters for Forest Condition Assessment of the Changbai Mountain National Nature Reserve

2019 ◽  
Vol 11 (24) ◽  
pp. 3004 ◽  
Author(s):  
Lin Chen ◽  
Chunying Ren ◽  
Bai Zhang ◽  
Zongming Wang ◽  
Yeqiao Wang
Keyword(s):  
Soil Fertility ◽  
Nature Reserve ◽  
Stand Density ◽  
Condition Assessment ◽  
Structure And Function ◽  
Forest Age ◽  
Stand Volume ◽  
Forest Condition ◽  
And Function ◽  
Forest Conditions

Forest condition is the baseline information for ecological evaluation and management. The National Forest Inventory of China contains structural parameters, such as canopy closure, stand density and forest age, and functional parameters, such as stand volume and soil fertility. Conventionally forest conditions are assessed through parameters collected from field observations, which could be costly and spatially limited. It is crucial to develop modeling approaches in mapping forest assessment parameters from satellite remote sensing. This study mapped structure and function parameters for forest condition assessment in the Changbai Mountain National Nature Reserve (CMNNR). The mapping algorithms, including statistical regression, random forests, and random forest kriging, were employed with predictors from Advanced Land Observing Satellite (ALOS)-2, Sentinel-1, Sentinel-2 satellite sensors, digital surface model of ALOS, and 1803 field sampled forest plots. Combined predicted parameters and weights from principal component analysis, forest conditions were assessed. The models explained spatial dynamics and characteristics of forest parameters based on an independent validation with all r values above 0.75. The root mean square error (RMSE) values of canopy closure, stand density, stand volume, forest age and soil fertility were 4.6%, 33.8%, 29.4%, 20.5%, and 14.3%, respectively. The mean assessment score suggested that forest conditions in the CMNNR are mainly resulted from spatial variations of function parameters such as stand volume and soil fertility. This study provides a methodology on forest condition assessment at regional scales, as well as the up-to-date information for the forest ecosystem in the CMNNR.

Regional ecosystem structure and function: ecological insights from remote sensing of tropical forests

2007 ◽  
Vol 22 (8) ◽  
pp. 414-423 ◽  
Author(s):  
Jeffrey Q. Chambers ◽  
Gregory P. Asner ◽  
Douglas C. Morton ◽  
Liana O. Anderson ◽  
Sassan S. Saatchi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Tropical Forests ◽  
Structure And Function ◽  
Ecosystem Structure ◽  
And Function ◽  
Ecosystem Structure And Function

scholarly journals New methods of spatial analysis in urban gardens inform future vegetation surveying

2020 ◽  
Vol 35 (3) ◽  
pp. 761-778
Author(s):  
Monika H. Egerer ◽  
Benjamin Wagner ◽  
Brenda B. Lin ◽  
Dave Kendal ◽  
Kai Zhu
Keyword(s):  
Spatial Scale ◽  
Vegetation Structure ◽  
New Technologies ◽  
Spatial Scales ◽  
Community Gardens ◽  
Structure And Function ◽  
Future Application ◽  
Future Research ◽  
Traditional Methods ◽  
And Function

Abstract Context Land use change requires measuring shifting patterns in biodiversity at various spatial scales to inform landscape management. Assessing vegetation change at different scales is challenging in urban ecosystems managed by many individuals. Thus, we do not know much about the structure and function of green spaces that support biodiversity. Objective We aim to understand how vegetation structure and function indicators in urban community gardens vary with spatial scale, applying new and traditional methods in landscape ecology to inform future research and application. Methods We performed two methods to assess garden vegetation structure (height) and function (species diversity, cover) at the garden- and garden plot scale. First, we used traditional field sampling to estimate garden vegetation at the garden scale (1 m2 quadrats along transects) and at the plot scale (estimated within entire plot) to measure height, diversity and cover. Second, we used UAV aerial imagery to derive measures of garden and plot vegetation using canopy height models (CHMs). We evaluated differences in CHMs at each scale across the gardens, and compared field and UAV-derived measures. Results Garden vegetation characteristics vary with spatial scale. Plant species richness and vegetation cover, but not height, related to UAV-derived imagery. Conclusions New technologies paired with traditional field methods can together inform how vegetation structure and function vary with spatial scale in urban landscapes. Spatial scale is key to accurate and meaningful urban vegetation analyses. New and traditional methods in urban ecology research should develop together to improve and streamline their future application.

scholarly journals Remote sensing of dryland ecosystem structure and function: Progress, challenges, and opportunities

2019 ◽  
Vol 233 ◽  
pp. 111401 ◽  
Author(s):  
William K. Smith ◽  
Matthew P. Dannenberg ◽  
Dong Yan ◽  
Stefanie Herrmann ◽  
Mallory L. Barnes ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Structure And Function ◽  
Ecosystem Structure ◽  
Challenges And Opportunities ◽  
And Function ◽  
Ecosystem Structure And Function

scholarly journals Groundwater-dependent ecosystems: recent insights, new techniques and an ecosystem-scale threshold response

2015 ◽  
Vol 12 (5) ◽  
pp. 4677-4754 ◽  
Author(s):  
D. Eamus ◽  
S. Zolfaghar ◽  
R. Villalobos-Vega ◽  
J. Cleverly ◽  
A. Huete
Keyword(s):  
Remote Sensing ◽  
Stable Isotopes ◽  
Isotope Analysis ◽  
Structure And Function ◽  
Ecosystem Structure ◽  
Groundwater Extraction ◽  
Groundwater Dependent Ecosystems ◽  
And Function ◽  
Remote Sensing Methods ◽  
Semi Arid

Abstract. Groundwater-dependent ecosystems (GDEs) are at risk globally due to unsustainable levels of groundwater extraction, especially in arid and semi-arid regions. In this review, we examine recent developments in the ecohydrology of GDEs with a focus on three knowledge gaps: (1) how do we locate GDEs, (2) how much water is transpired from shallow aquifers by GDEs; and (3) what are the responses of GDEs to excessive groundwater extraction? The answers to these questions will determine water allocations that are required to sustain functioning of GDEs and to guide regulations on groundwater extraction to avoid negative impacts on GDEs. We discuss three methods for identifying GDEs: (1) fluctuations in depth-to-groundwater that are associated with diurnal variations in transpiration, (2) stable isotope analysis of water sources in the transpiration stream; and (3) remote sensing methods. We then discuss several methods for estimating rates of GW use, including direct measurement using sapflux or eddy covariance technologies, estimation of a climate wetness index within a Budyko framework, spatial distribution of ET using remote sensing, groundwater modelling and stable isotopes. Remote sensing methods often rely on direct measurements to calibrate the relationship between vegetation indices and ET. ET from GDEs is also determined using hydrologic models of varying complexity, from the "White method" to fully coupled, variable saturation models. Combinations of methods are typically employed to obtain clearer insight into the components of groundwater discharge in GDEs, such as the proportional importance of transpiration vs. evaporation (e.g., using stable isotopes) or from groundwater vs. rainwater sources. Groundwater extraction can have severe consequences on structure and function of GDEs. In the most extreme cases, phreatophytes experience crown dieback and death following groundwater drawdown. We provide a brief review of two case studies of the impacts of GW extraction and discuss the use of C isotope ratios in xylem to reveal past influences of GW extraction. We conclude with a discussion of a depth-to-groundwater threshold in mesic and semi-arid GDEs. Across this threshold, significant changes occur in ecosystem structure and function.

scholarly journals Current Trends in Forest Ecological Applications of Three-Dimensional Remote Sensing: Transition from Experimental to Operational Solutions?

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 891
Author(s):  
Hooman Latifi ◽  
Ruben Valbuena
Keyword(s):  
Remote Sensing ◽  
Forest Ecology ◽  
Three Dimensional ◽  
Remote Sensing Data ◽  
Structure And Function ◽  
Small Scale ◽  
Sensing Data ◽  
Composition Structure ◽  
And Function ◽  
Novel Applications

The alarming increase in the magnitude and spatiotemporal patterns of changes in composition, structure and function of forest ecosystems during recent years calls for enhanced cross-border mitigation and adaption measures, which strongly entail intensified research to understand the underlying processes in the ecosystems as well as their dynamics. Remote sensing data and methods are nowadays the main complementary sources of synoptic, up-to-date and objective information to support field observations in forest ecology. In particular, analysis of three-dimensional (3D) remote sensing data is regarded as an appropriate complement, since they are hypothesized to resemble the 3D character of most forest attributes. Following their use in various small-scale forest structural analyses over the past two decades, these sources of data are now on their way to be integrated in novel applications in fields like citizen science, environmental impact assessment, forest fire analysis, and biodiversity assessment in remote areas. These and a number of other novel applications provide valuable material for the Forests special issue “3D Remote Sensing Applications in Forest Ecology: Composition, Structure and Function”, which shows the promising future of these technologies and improves our understanding of the potentials and challenges of 3D remote sensing in practical forest ecology worldwide.

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