Incorporating local habitat heterogeneity and productivity measures when modelling vertebrate richness

2019 ◽  
Vol 47 (1) ◽  
pp. 7-14 ◽  
Author(s):  
W Justin Cooper ◽  
William J McShea ◽  
David A Luther ◽  
Tavis Forrester
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Spatial Scales ◽  
Model Performance ◽  
Remotely Sensed ◽  
Habitat Characteristics ◽  
Measurement Scale ◽  
Terrestrial Mammals ◽  
Declining Species ◽  
Monitoring Technologies

SummaryDeclining species richness is a global concern; however, the coarse-scale metrics used at regional or landscape levels might not accurately represent the important habitat characteristics needed to estimate species richness. Currently, there exists a lack of knowledge with regard to the spatial extent necessary to correlate remotely sensed habitat metrics to species richness and animal surveys. We provide a protocol for determining the best scale to use when merging remotely sensed habitat and animal survey data as a step towards improving estimates of vertebrate species richness on broad scales. We test the relative importance of fine-resolution habitat heterogeneity and productivity metrics at multiple spatial scales as predictors of species richness for birds, frogs and mammals using a Bayesian approach and a combination of passive monitoring technologies. Model performance was different for each taxonomic group and dependent on the scale at which habitat heterogeneity and productivity were measured. Optimal scales included a 20-m radius for bats and frogs, an 80-m radius for birds and a 180-m radius for terrestrial mammals. Our results indicate that optimal scales do exist when merging remotely sensed habitat measures with ground-based surveys, but they differ between vertebrate groups. Additionally, the selection of a measurement scale is highly influential to our understanding of the relationships between species richness and habitat characteristics.

scholarly journals Habitat features of settlement areas used by floaters of Bonelli’s and Golden Eagles

2010 ◽  
Vol 21 (1) ◽  
pp. 59-71 ◽  
Author(s):  
JESÚS CARO ◽  
DIEGO ONTIVEROS ◽  
MANUEL PIZARRO ◽  
JUAN M. PLEGUEZUELOS
Keyword(s):  
Iberian Peninsula ◽  
Habitat Heterogeneity ◽  
Habitat Characteristics ◽  
Mean Annual Temperature ◽  
Habitat Features ◽  
Ecological Requirements ◽  
Bonelli’S Eagle ◽  
Declining Species ◽  
Dispersal Period ◽  
Settlement Areas

SummaryBonelli’s Eagle Hieraaetus fasciatus and Golden Eagle Aquila chrysaetos are two declining species, in which floaters tend to be located outside of breeding territories during the dispersal period, in so-called settlement areas. We studied settlement areas for both these long-lived raptors in the southern Iberian Peninsula, to gain a better understanding of the ecological requirements of the eagles during their long pre-adult stage, a period accounting for around 80% of the species’ mortality. Eagle abundance was calculated by road censuses, and habitat characteristics of settlement and non-settlement areas compared by General Discriminant Analysis (GDA) and Logistic Regression (LR). The best model of GDA and LR incorporated the abundance of main prey for eagles (rabbits, partridges) and orchard surface area, and explained 100% of eagle presence; the best model selected by GDA also included habitat heterogeneity. Both eagles tended to share settlement areas in the southern Iberian Peninsula and, when they did not, the mean annual temperature and slope appeared to explain the segregation between the two species. Management measures for the conservation of both threatened species during the dispersal period should be focused on identifying settlement areas, maintaining high prey densities and maximum habitat heterogeneity.

scholarly journals Food plant diversity as broad-scale determinant of avian frugivore richness

2007 ◽  
Vol 274 (1611) ◽  
pp. 799-808 ◽  
Author(s):  
W. Daniel Kissling ◽  
Carsten Rahbek ◽  
Katrin Böhning-Gaese
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Spatial Scales ◽  
Fruit Size ◽  
Food Plant ◽  
Sub Saharan Africa ◽  
Food Plants ◽  
Close Relationship ◽  
Avian Frugivores ◽  
Sub Saharan

The causes of variation in animal species richness at large spatial scales are intensively debated. Here, we examine whether the diversity of food plants, contemporary climate and energy, or habitat heterogeneity determine species richness patterns of avian frugivores across sub-Saharan Africa. Path models indicate that species richness of Ficus (their fruits being one of the major food resources for frugivores in the tropics) has the strongest direct effect on richness of avian frugivores, whereas the influences of variables related to water–energy and habitat heterogeneity are mainly indirect. The importance of Ficus richness for richness of avian frugivores diminishes with decreasing specialization of birds on fruit eating, but is retained when accounting for spatial autocorrelation. We suggest that a positive relationship between food plant and frugivore species richness could result from niche assembly mechanisms (e.g. coevolutionary adaptations to fruit size, fruit colour or vertical stratification of fruit presentation) or, alternatively, from stochastic speciation–extinction processes. In any case, the close relationship between species richness of Ficus and avian frugivores suggests that figs are keystone resources for animal consumers, even at continental scales.

scholarly journals Using empirical and simulated data to study the influence of environmental heterogeneity on fish species richness in two biogeographic provinces

2014 ◽  
Author(s):  
Philippe Massicotte ◽  
Raphael Proulx ◽  
Gilbert Cabana ◽  
Marco Rodriguez
Keyword(s):  
Species Richness ◽  
Fish Species ◽  
Habitat Heterogeneity ◽  
Environmental Variables ◽  
Spatial Scales ◽  
Simulated Data ◽  
Aquatic Communities ◽  
Modeling Framework ◽  
Heterogeneous Habitats ◽  
Biogeographic Provinces

Loss of species richness in aquatic ecosystems is occurring rapidly and many factors, including habitat heterogeneity, have been suggested to affect the diversity of aquatic communities. We used fish community data (> 200 species) from extensive surveys conducted in two biogeographic provinces (extent > 1000 km) in North America to test the hypothesis that fish species richness is greater in more heterogeneous habitats (grain < 10 km2). Our tests are based on samples collected at nearly 800 stations over a period of five years. Using a set of environmental variables routinely measured by monitoring programs and a random placement model of community assembly, we demonstrate that fish species richness in coastal ecosystems is associated locally with the spatial heterogeneity of environmental variables but not with their magnitude. The observed effect of heterogeneity on species richness was substantially greater than that generated by simulations. Our modeling framework opens avenues for targeted conservation of habitat heterogeneity at broader temporal and spatial scales.

Mangroves as Fish Habitat

2015 ◽  
Keyword(s):  
Water Quality ◽  
Particle Size ◽  
Species Richness ◽  
Fish Species ◽  
Fish Community ◽  
Spatial Scales ◽  
Quality Parameters ◽  
Habitat Characteristics ◽  
Fish Community Structure ◽  
Simultaneous Assessment

<em>Abstract</em>.—Three adjacent tidal creek systems (Page, Kemps, and Broad creeks) on Cape Eleuthera, The Bahamas were studied to quantify the variation in fish community structure and habitat characteristics over small (<5 km) spatial scales. Snorkeling transects were used to census the fish community on a summer new moon during slack high tide and involved the simultaneous assessment of each creek and each zone within the creek (i.e., mouth, middle, and upper) replicated over three consecutive days. The simultaneous assessment (involving large teams) was done to enable direct comparison without spatial sampling being confounded by time. Habitat assessments included measurements of water quality parameters, sediment sampling, and vegetation surveys. Despite their close proximity, creeks differed in both fish community structure and habitat characteristics. Broad Creek had the greatest fish species richness (<em>n </em>= 15), followed by Kemps Creek (<em>n </em>= 14) and Page Creek (<em>n </em>= 10). Mangrove habitats had significantly greater fish species diversity in Broad Creek while sea grass habitats resulted in higher species richness in Page Creek, relative to other habitat types. Mangrove and algal plain habitats had the highest fish species diversity in Kemps Creek. Within creeks, fish abundance was dependent on zonation, with the largest number of fish being found in creek mouths compared to upper sections. Water quality parameters (i.e., temperature, dissolved oxygen, and salinity) differed among the creeks, presumably reflecting creek morphology. Out of the 10 different species of vegetation observed, 60% were found in all tidal creeks. Coarse sand was the predominant particle size for all creeks, with variation in the second most abundant particle size between Page Creek and the others. This study reveals the great heterogeneity of tidal creek fish community and habitat characteristics and illustrates that conservation and management strategies along with monitoring programs must recognize the variation that can occur among and within coastal creeks over relatively small spatial scales.

scholarly journals Using empirical and simulated data to study the influence of environmental heterogeneity on fish species richness in two biogeographic provinces

2014 ◽  
Author(s):  
Philippe Massicotte ◽  
Raphael Proulx ◽  
Gilbert Cabana ◽  
Marco Rodriguez
Keyword(s):  
Species Richness ◽  
Fish Species ◽  
Habitat Heterogeneity ◽  
Environmental Variables ◽  
Spatial Scales ◽  
Simulated Data ◽  
Aquatic Communities ◽  
Modeling Framework ◽  
Heterogeneous Habitats ◽  
Biogeographic Provinces

Loss of species richness in aquatic ecosystems is occurring rapidly and many factors, including habitat heterogeneity, have been suggested to affect the diversity of aquatic communities. We used fish community data (> 200 species) from extensive surveys conducted in two biogeographic provinces (extent > 1000 km) in North America to test the hypothesis that fish species richness is greater in more heterogeneous habitats (grain < 10 km2). Our tests are based on samples collected at nearly 800 stations over a period of five years. Using a set of environmental variables routinely measured by monitoring programs and a random placement model of community assembly, we demonstrate that fish species richness in coastal ecosystems is associated locally with the spatial heterogeneity of environmental variables but not with their magnitude. The observed effect of heterogeneity on species richness was substantially greater than that generated by simulations. Our modeling framework opens avenues for targeted conservation of habitat heterogeneity at broader temporal and spatial scales.

scholarly journals Mapping differences in mammalian distributions and diversity using environmental DNA from rivers

2021 ◽  
Author(s):  
Holly A. Broadhurst ◽  
Luke M. Gregory ◽  
Emma K. Bleakley ◽  
Joseph C. Perkins ◽  
Jenna V. Lavin ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Dynamics ◽  
Spatial Scales ◽  
Environmental Dna ◽  
Community Diversity ◽  
Individual Species ◽  
Sampling Effort ◽  
Mammal Species ◽  
Terrestrial Mammals ◽  
Β Diversity

AbstractAimFinding more efficient ways to monitor, and estimate the diversity of, mammalian communities is a major step towards their management and conservation. Environmental DNA (eDNA) from river water has recently been shown to be a viable method for biomonitoring mammalian communities. Yet, most of the studies to date have focused on the potential for eDNA to detect individual species, with little focus on describing patterns of community diversity and structure. In this study, we focus on the sampling effort required to reliably map the diversity and distribution of semi-aquatic and terrestrial mammals and allow inferences of community structure surrounding rivers.LocationSoutheastern EnglandMethodsWe used eDNA metabarcoding on water samples collected along two rivers and a beaver enclosure over two days, targeting terrestrial and semi-aquatic mammals. Mammalian community diversity and composition was assessed based on species richness and β-diversity. Differences between river communities were calculated and partitioned into nestedness and turnover, and the sampling effort required to rapidly detect semi-aquatic and terrestrial species was evaluated based on species accumulation curves and occupancy modelling.ResultseDNA metabarcoding efficiently detected 25 wild mammal species from five orders in two days of sampling, representing the vast majority (82%) of the species expected in the area. The required sampling effort varied between orders, with common species (generally rodents, deer and lagomorph species) more readily detected, with carnivores detected less frequently. Measures of species richness differed between rivers (both overall and within each mammalian order) and patterns of β-diversity revealed the importance of species replacement in sites within each river, against a pattern of species loss between the two rivers.Main conclusionseDNA metabarcoding demonstrated its capability to rapidly detect mammal species, allowing inferences of community composition that will better inform future sampling strategies for this Class. Importantly, this study highlights the potential use of eDNA data for investigating mammalian community dynamics over different spatial scales.

scholarly journals Estimates of Species Richness and Composition Depend on Detection Method in Assemblages of Terrestrial Mammals

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 186
Author(s):  
Bruno D. Suárez-Tangil ◽  
Alejandro Rodríguez
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Spatial Scales ◽  
Camera Traps ◽  
Survey Method ◽  
Sampling Effort ◽  
Method Performance ◽  
Terrestrial Mammals ◽  
Mediterranean Landscapes ◽  
The Impact

Detecting rapid changes in mammal composition at large spatial scales requires efficient detection methods. Many studies estimate species composition with a single survey method without asking whether that particular method optimises detection for all occurring species and yields reliable community-level indices. We explore the implications of between-method differences in efficiency, consistency, and sampling effort for the basic characterisation of assemblages of medium to large mammals in a region with three contrasted Mediterranean landscapes. We assessed differences between camera traps, scent stations, scat surveys, and track surveys. Using track surveys, we detected all species present in the regional pool (13) and obtained the most accurate description of local species richness and composition with the lowest sampling effort (16 sampling units and 2 survey sessions at most). Had we chosen camera traps, scent stations, or scat surveys as the only survey method, we would have underestimated species richness (9, 11, and 12 species, respectively) and misrepresented species composition in varying degrees. Preliminary studies of method performance inform whether single or multiple survey methods are needed and eventually which single method might be most appropriate. Without such a formal assessment current practices may produce unreliable and incomplete species inventories, ultimately leading to incorrect conclusions about the impact of human activity on mammal communities.

scholarly journals A Review of Reconstructing Remotely Sensed Land Surface Temperature under Cloudy Conditions

2021 ◽  
Vol 13 (14) ◽  
pp. 2838
Author(s):  
Yaping Mo ◽  
Yongming Xu ◽  
Huijuan Chen ◽  
Shanyou Zhu
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Spatial Scales ◽  
Remotely Sensed ◽  
Urban Heat Islands ◽  
Reconstruction Algorithms ◽  
Gap Filling ◽  
Practical Applications ◽  
Data Gaps

Land surface temperature (LST) is an important environmental parameter in climate change, urban heat islands, drought, public health, and other fields. Thermal infrared (TIR) remote sensing is the main method used to obtain LST information over large spatial scales. However, cloud cover results in many data gaps in remotely sensed LST datasets, greatly limiting their practical applications. Many studies have sought to fill these data gaps and reconstruct cloud-free LST datasets over the last few decades. This paper reviews the progress of LST reconstruction research. A bibliometric analysis is conducted to provide a brief overview of the papers published in this field. The existing reconstruction algorithms can be grouped into five categories: spatial gap-filling methods, temporal gap-filling methods, spatiotemporal gap-filling methods, multi-source fusion-based gap-filling methods, and surface energy balance-based gap-filling methods. The principles, advantages, and limitations of these methods are described and discussed. The applications of these methods are also outlined. In addition, the validation of filled LST values’ cloudy pixels is an important concern in LST reconstruction. The different validation methods applied for reconstructed LST datasets are also reviewed herein. Finally, prospects for future developments in LST reconstruction are provided.

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