scholarly journals Disentangling LiDAR Contribution in Modelling Species–Habitat Structure Relationships in Terrestrial Ecosystems Worldwide. A Systematic Review and Future Directions

2021 ◽  
Vol 13 (17) ◽  
pp. 3447
Author(s):  
Pablo Acebes ◽  
Paula Lillo ◽  
Carlos Jaime-González
Keyword(s):  
Habitat Structure ◽  
Temperate Forest ◽  
Canopy Cover ◽  
Terrestrial Ecosystems ◽  
Accurate Information ◽  
Ecosystem Structure ◽  
Anthropogenic Pressures ◽  
Future Directions ◽  
Taxonomic Groups ◽  
Biodiversity Mapping

Global biodiversity is threatened by unprecedented and increasing anthropogenic pressures, including habitat loss and fragmentation. LiDAR can become a decisive technology by providing accurate information about the linkages between biodiversity and ecosystem structure. Here, we review the current use of LiDAR metrics in ecological studies regarding birds, mammals, reptiles, amphibians, invertebrates, bryophytes, lichens, and fungi (BLF). We quantify the types of research (ecosystem and LiDAR sources) and describe the LiDAR platforms and data that are currently available. We also categorize and harmonize LiDAR metrics into five LiDAR morphological traits (canopy cover, height and vertical distribution, understory and shrubland, and topographic traits) and quantify their current use and effectiveness across taxonomic groups and ecosystems. The literature review returned 173 papers that met our criteria. Europe and North America held most of the studies, and birds were the most studied group, whereas temperate forest was by far the most represented ecosystem. Globally, canopy height was the most used LiDAR trait, especially in forest ecosystems, whereas canopy cover and terrain topography traits performed better in those ecosystems where they were mapped. Understory structure and shrubland traits together with terrain topography showed high effectiveness for less studied groups such as BLF and invertebrates and in open landscapes. Our results show how LiDAR technology has greatly contributed to habitat mapping, including organisms poorly studied until recently, such as BLF. Finally, we discuss the forthcoming opportunities for biodiversity mapping with different LiDAR platforms in combination with spectral information. We advocate (i) for the integration of spaceborne LiDAR data with the already available airborne (airplane, drones) and terrestrial technology, and (ii) the coupling of it with multispectral/hyperspectral information, which will allow for the exploration and analyses of new species and ecosystems.

scholarly journals Rapid response of habitat structure and above-ground carbon storage to altered fire regimes in tropical savanna

2019 ◽  
Vol 16 (7) ◽  
pp. 1493-1503 ◽  
Author(s):  
Shaun R. Levick ◽  
Anna E. Richards ◽  
Garry D. Cook ◽  
Jon Schatz ◽  
Marcus Guderle ◽  
...  
Keyword(s):  
Carbon Storage ◽  
Vegetation Structure ◽  
Habitat Structure ◽  
Canopy Structure ◽  
Three Dimensional ◽  
Canopy Cover ◽  
Fire Regimes ◽  
Dry Season ◽  
Airborne Lidar ◽  
Climate Conditions

Abstract. Fire regimes across the globe have been altered through changes in land use, land management, and climate conditions. Understanding how these modified fire regimes impact vegetation structure and dynamics is essential for informed biodiversity conservation and carbon management in savanna ecosystems. We used a fire experiment at the Territory Wildlife Park (TWP), northern Australia, to investigate the consequences of altered fire regimes for vertical habitat structure and above-ground carbon storage. We mapped vegetation three-dimensional (3-D) structure in high spatial resolution with airborne lidar across 18 replicated 1 ha plots of varying fire frequency and season treatments. We used lidar-derived canopy height and cover metrics to extrapolate field-based measures of woody biomass to the full extent of the experimental site (R2=0.82, RMSE = 7.35 t C ha−1) and analysed differences in above-ground carbon storage and canopy structure among treatments. Woody canopy cover and biomass were highest in the absence of fire (76 % and 39.8 t C ha−1) and lowest in plots burnt late in the dry season on a biennial basis (42 % and 18.2 t C ha−1). Woody canopy vertical profiles differed among all six fire treatments, with the greatest divergence in height classes <5 m. The magnitude of fire effects on vegetation structure varied along the environmental gradient underpinning the experiment, with less reduction in biomass in plots with deeper soils. Our results highlight the large extent to which fire management can shape woody structural patterns in savanna landscapes, even over time frames as short as a decade. The structural profile changes shown here, and the quantification of carbon reduction under late dry season burning, have important implications for habitat conservation, carbon sequestration, and emission reduction initiatives in the region.

Fine-scale habitat use by the southern emu-wren (Stipiturus malachurus)

2006 ◽  
Vol 33 (2) ◽  
pp. 137 ◽  
Author(s):  
Grainne S. Maguire
Keyword(s):  
Habitat Use ◽  
Plant Species ◽  
Habitat Structure ◽  
Canopy Cover ◽  
Ground Level ◽  
Fine Scale ◽  
Vegetation Height ◽  
Vertical Density ◽  
Foliage Density ◽  
Floristic Characteristics

Fine-scale variation in habitat structure and composition is likely to influence habitat use by avian species with limited flight capabilities. I investigated proportional use of available habitat and microhabitat by the southern emu-wren (Stipiturus malachurus), a threatened, flight-limited passerine, at three sites in Victoria, in relation to vegetation structure and composition. Emu-wrens appeared to discriminate between habitats with regard to structural rather than floristic characteristics. Habitats with dense vertical foliage of shrubs, grasses and sedges/rushes between ground level and 100 cm, and dense horizontal cover of medium to tall shrubs, were used most frequently. However, when availability of habitat was taken into account, habitat use was negatively correlated with the vertical density of low shrub foliage and species richness. Within habitats, emu-wrens more frequently used plant species that had a dense canopy cover (26 ± 2% of total cover, crown diameter 93 ± 5 cm), high foliage density between 50 and 100 cm, and average heights of ~1 m. Plant species in which the birds nested comprised ~14% of total canopy cover and were densest between ground level and 50 cm. Canopy cover, vegetation height and vertical foliage density were consistently important variables correlated with emu-wren habitat use at multiple fine-scales. This study provides valuable information for conservation management of the species; in particular, the restoration of degraded habitats.

scholarly journals Valuing biodiversity and ecosystem services: a useful way to manage and conserve marine resources?

2016 ◽  
Vol 283 (1844) ◽  
pp. 20161635 ◽  
Author(s):  
Rachel D. Cavanagh ◽  
Stefanie Broszeit ◽  
Graham M. Pilling ◽  
Susie M. Grant ◽  
Eugene J. Murphy ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Best Practice ◽  
Terrestrial Ecosystems ◽  
Marine Conservation ◽  
Marine Biodiversity ◽  
Marine Resources ◽  
Ecosystem Structure ◽  
Ecosystem Structure And Functioning ◽  
Conservation And Management ◽  
The Tropical Pacific

Valuation of biodiversity and ecosystem services (ES) is widely recognized as a useful, though often controversial, approach to conservation and management. However, its use in the marine environment, hence evidence of its efficacy, lags behind that in terrestrial ecosystems. This largely reflects key challenges to marine conservation and management such as the practical difficulties in studying the ocean, complex governance issues and the historically-rooted separation of biodiversity conservation and resource management. Given these challenges together with the accelerating loss of marine biodiversity (and threats to the ES that this biodiversity supports), we ask whether valuation efforts for marine ecosystems are appropriate and effective. We compare three contrasting systems: the tropical Pacific, Southern Ocean and UK coastal seas. In doing so, we reveal a diversity in valuation approaches with different rates of progress and success. We also find a tendency to focus on specific ES (often the harvested species) rather than biodiversity. In light of our findings, we present a new conceptual view of valuation that should ideally be considered in decision-making. Accounting for the critical relationships between biodiversity and ES, together with an understanding of ecosystem structure and functioning, will enable the wider implications of marine conservation and management decisions to be evaluated. We recommend embedding valuation within existing management structures, rather than treating it as an alternative or additional mechanism. However, we caution that its uptake and efficacy will be compromised without the ability to develop and share best practice across regions.

The Riddle Of Nde For Embrittlemient Detection

1997 ◽  
Vol 503 ◽  
Author(s):  
M. Blaszkiewicz
Keyword(s):  
Nuclear Reactor ◽  
Hyperfine Interactions ◽  
Pressure Vessels ◽  
Nuclear Industry ◽  
Accurate Information ◽  
Destructive Testing ◽  
Future Directions ◽  
Integrity Assessment ◽  
Nondestructive Techniques ◽  
Surveillance Programs

ABSTRACTThe ability to nondestructively determine the level of irradiation induced degradation in nuclear reactor pressure vessels (RPVs) would enhance the integrity assessment currently used by the nuclear industry. Presently, destructive testing of Charpy specimens from surveillance capsules is used to approximate the RPV upper shelf energy and the ductile-to-brittle transition temperature, and approved models and guidelines are used to determine the state of embrittlement. However, these models and surveillance programs do not always provide enough accurate information to support decisions for premature RPV life termination, life continuation to license expiration, or life renewal and extension by means of annealing. Effective nondestructive techniques would extend the usefulness of the surveillance material by reducing the amount of material used for destructive studies, and ultimately by allowing tests to be performed directly on the RPV. Nondestructive techniques, ranging from electrical resistivity to hyperfine interactions, have been, and continue to be, explored for use in embrittlement assessment. The current states of these various techniques are discussed, and future directions for research are suggested.

Summer and winter bird populations associated with five age-classes of aspen forest in Alberta

1993 ◽  
Vol 23 (9) ◽  
pp. 1830-1836 ◽  
Author(s):  
D. A. Westworth ◽  
E. S. Telfer
Keyword(s):  
Habitat Structure ◽  
Bird Species ◽  
Canopy Cover ◽  
Species Number ◽  
Age Classes ◽  
Bird Populations ◽  
Clear Cut ◽  
Number Of Species ◽  
Bird Density ◽  
Large Trees

Summer and winter bird use of aspen forests was studied in west central Alberta. Forest age-classes in the study included 1- and 2-year-old clear-cut areas and.14-, 30-, 60-, and 80-year-old stands. Habitat structure and composition were quantified by a combination of measurement and estimation of variables. Density of the breeding bird population was estimated by territorial mapping. Changes in habitat structure between different age-classes resulted in a successional replacement of bird species. Number of individuals was greatest in 14-year-old stands at 656 territories per 100 ha, probably owing to the presence of remnant snags and of large trees that had survived past fires. The 30-year-old stands supported 312 territories per 100 ha, 60-year-old stands 380 territories, and 80-year-old stands 231 territories, respectively. Recently clear-cut areas supported only 110 territories. Number of species followed the same pattern with 25 in 14-year-old stands, 22 in the 30-year-old stands, 21 in the 60-year-old stands, and 14 in the 80-year-old stands. Recent clearcuts supported 10 species. In winter 13 bird species were recorded in the combined clear-cut, 14-, 30-, and 60-year-old stands. The highest number of species (11) were recorded in the 60-year-old stand during winter but the greatest winter bird density (125 individuals/100 ha) occurred in the 30-year-old stand. Three principal components extracted from the habitat data explained 83.2% of the variance in bird use. The components corresponded to gradients in canopy cover, occurrence of conifers, and shrub density.

scholarly journals Influence of habitat structure on Pristimantis species (Anura: Craugastoridae) in a bamboo-dominated forest fragment in southwestern Amazonia

2015 ◽  
Vol 14 (1) ◽  
pp. 19
Author(s):  
Jhon Jairo López-Rojas ◽  
Moisés Barbosa Souza ◽  
Elder Ferreira Morato
Keyword(s):  
Species Composition ◽  
Habitat Structure ◽  
Neutral Theory ◽  
Canopy Cover ◽  
Spatial Distance ◽  
Niche Theory ◽  
Forest Fragment ◽  
Biodiversity Research ◽  
Remnant Forest ◽  
Southwestern Amazonia

Structural and determinate factors for the composition of assemblages of species are diverse. Two theories attempt to explain the pattern of species composition in assemblies using different approaches—i.e., Niche Theory and Neutral Theory. Anurans have complex responses to habitat structure. Species of Pristimantis are good indicators for conservation because they are organisms with direct development. The effect of habitat structure on species of Pristimantis in a bamboo-dominated remnant forest located in southwestern Amazonia is analyzed herein. Active visual and auditory searches in 10 plots of the Biodiversity Research Program (PPBio) were conducted between November 2012 and May 2013. Four hundred and sixty individuals of five species were recorded: Pristimantis altamazonicus, P. diadematus, P. fenestratus, P. reichlei, and P. skydmainus. Neither spatial distance nor the structure of the habitat of the plots affected the composition of Pristimantis. The first axis of PCA explained 45.6% variation of the characterization habitat structure, correlated significantly with the number of Pristimantis, species increasing with trees between 10 ≤ dbh &lt; 30 cm and decreased with density of bamboo. The increase in litter depth and canopy cover influenced in the occurrence of P. reichlei, the occurrence of P. skydmainus decreased with increased density of bamboo and trees dbh ≥ 30 cm and the occurrence of P. diadematus decreased relative to increased canopy cover. Pristimantis diadematus and P. skydmainus were the most restricted species in terms of habitat and were especially susceptible to bamboo density.

scholarly journals Cyanobacteria as a Nature-Based Biotechnological Tool for Restoring Salt-Affected Soils

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1321
Author(s):  
Francisco Rocha ◽  
Manuel Esteban Lucas-Borja ◽  
Paulo Pereira ◽  
Miriam Muñoz-Rojas
Keyword(s):  
Current Knowledge ◽  
Ecosystem Restoration ◽  
Terrestrial Ecosystems ◽  
Soil Salinization ◽  
Soil Conditions ◽  
Natural Ecosystems ◽  
Anthropogenic Pressures ◽  
Salt Leaching ◽  
Wide Range ◽  
Salt Affected Soils

Soil salinization poses an important threat to terrestrial ecosystems and is expected to increase as a consequence of climate change and anthropogenic pressures. Conventional methods such as salt-leaching or application of soil amendments, or nature-based solutions (NBSs) such as phytoremediation, have been widely adopted with contrasting results. The use of cyanobacteria for improving soil conditions has emerged as a novel biotechnological tool for ecosystem restoration due to the unique features of these organisms, e.g., ability to fix carbon and nitrogen and promote soil stabilisation. Cyanobacteria distribute over a wide range of salt concentrations and several species can adapt to fluctuating salinity conditions. Their application in agricultural saline soil remediation has been demonstrated, mostly in laboratory studies, but there is a lack of research regarding their use in natural ecosystems restoration. In this article, we provide an overview of the current knowledge on cyanobacteria in the context of ecosystem restoration. Examples of the application of cyanobacteria in alleviating salt-stress in plants and soils are presented. Furthermore, we acknowledge gaps regarding the extensive application of cyanobacteria in salt-affected soils remediation and discuss the challenges of NBSs in salt-affected soils restoration.

scholarly journals Search Tactics of Insectivorous Birds Foraging in an Australian Eucalypt Forest

The Auk ◽  
1986 ◽  
Vol 103 (3) ◽  
pp. 515-530 ◽  
Author(s):  
Richard T. Holmes ◽  
Harry F. Recher
Keyword(s):  
Habitat Structure ◽  
Temperate Forest ◽  
Prey Capture ◽  
Bird Species ◽  
Bird Community ◽  
Insectivorous Birds ◽  
Community Patterns ◽  
Eucalypt Forest ◽  
Eucalyptus Forest ◽  
Forest Habitats

Abstract The different ways birds searched for food in an Australian Eucalyptus forest led them to detect and capture different kinds of prey. Five major searching modes were identified among 23 common, mostly insectivorous bird species. These were distinguished largely by the rates, distances, and angles moved by birds while foraging and by their prey-capture behavior. Some bird species typically moved slowly, visually examining substrates at relatively long distances, and then took flight to capture prey (e.g. whistlers, flycatchers, muscicapid robins, cuckoos). Others moved at more rapid rates and either gleaned small prey from nearby substrates (e.g. thornbills, treecreepers) or flushed insects that were then pursued (e.g. fantails). Two species (Eastern Shrike-Tit, Falcunculus frontatus; White-eared Honeyeater, Meliphaga leucotis) were specialized substrate-restricted searchers, seeking invertebrate and carbohydrate foods among the exfoliating bark of Eucalyptus. The search tactics of birds in this south temperate Australian forest were similar to those of birds in a north temperate forest in New Hampshire, USA, previously reported by Robinson and Holmes (1982). The differences in food-searching behavior between these phylogenetically distinct avifaunas (e.g. search flight and prey-attack flight lengths, hop/flight ratios, foraging rates) reflect the effects of unique foliage structures (e.g. spacing of branches, arrangements of leaves) and food resources at each site. These findings support the hypothesis that habitat structure and food availability provide opportunities and constraints on how birds search for and capture food in forest habitats. These in turn are postulated to affect the success of particular bird species exploiting those habitats and thus influence bird community patterns.

scholarly journals Blockchain-Based Digital Contact Tracing Apps for COVID-19 Pandemic Management: Issues, Challenges, Solutions, and Future Directions (Preprint)

2020 ◽  
Author(s):  
Sheikh Mohammad Idrees ◽  
Mariusz Nowostawski ◽  
Roshan Jameel
Keyword(s):  
Personal Information ◽  
Data Encryption ◽  
Contact Tracing ◽  
Accurate Information ◽  
Effective Technique ◽  
Privacy And Security ◽  
Future Directions ◽  
Blockchain Technology ◽  
Privacy And Confidentiality ◽  
Management Issues

UNSTRUCTURED The COVID-19 pandemic has caused substantial global disturbance by affecting more than 42 million people (as of the end of October 2020). Since there is no medication or vaccine available, the only way to combat it is to minimize transmission. Digital contact tracing is an effective technique that can be utilized for this purpose, as it eliminates the manual contact tracing process and could help in identifying and isolating affected people. However, users are reluctant to share their location and contact details due to concerns related to the privacy and security of their personal information, which affects its implementation and extensive adoption. Blockchain technology has been applied in various domains and has been proven to be an effective approach for handling data transactions securely, which makes it an ideal choice for digital contact tracing apps. The properties of blockchain such as time stamping and immutability of data may facilitate the retrieval of accurate information on the trail of the virus in a transparent manner, while data encryption assures the integrity of the information being provided. Furthermore, the anonymity of the user’s identity alleviates some of the risks related to privacy and confidentiality concerns. In this paper, we provide readers with a detailed discussion on the digital contact tracing mechanism and outline the apps developed so far to combat the COVID-19 pandemic. Moreover, we present the possible risks, issues, and challenges associated with the available contact tracing apps and analyze how the adoption of a blockchain-based decentralized network for handling the app could provide users with privacy-preserving contact tracing without compromising performance and efficiency.

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