Contributions of gopher mound and casting disturbances to plant community structure in a Cascade Range meadow complex

Pocket gophers (Geomyidae) are major agents of disturbance in North American grasslands. Gopher mounds bury existing plants and influence community structure through various mechanisms. However, in mountain meadows that experience winter snowpack, gophers also create winter castings, smaller tube-shaped deposits, previously ignored in studies of plant–gopher disturbance relationships. We studied the influences of the Mazama pocket gopher (Thomomys mazama Merriam, 1897) in montane meadows of the Oregon Cascades, quantifying community patterns at larger spatial scales than previously studied in this system and considering, for the first time, effects of both mounds and castings. We measured cover of disturbance and individual plant species along twenty 5 m transects in each of four plots with differing species composition. Total plant cover was negatively correlated with mounds and castings. However, only mounds influenced growth-form dominance, reducing graminoid cover and increasing the forb–graminoid ratio — effects attributable to the greater volume and longevity of mounds. Forb-disturbance relationships were variable among plots, likely due to differences in species’ tolerance of burial. Transect-scale richness and heterogeneity (variation in composition within transects) increased with disturbance. We conclude that frequent, small-scale disturbances create a shifting mosaic of vegetation states, reducing graminoid dominance and enhancing species richness and heterogeneity at larger spatial scales.

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Spatial analysis of phylogenetic community structure: New version of a classical method

10.7287/peerj.preprints.927 ◽

2015 ◽

Author(s):

Carlo Ricotta ◽

Eszter EA Ari ◽

Giuliano Bonanomi ◽

Francesco Giannino ◽

Duncan Heathfield ◽

...

Keyword(s):

Community Structure ◽

Spatial Scales ◽

Point Pattern ◽

Maximum Deviation ◽

Individual Plant ◽

Phylogenetic Distance ◽

Phylogenetic Structure ◽

Phylogenetic Community Structure ◽

Point Patterns ◽

Wide Range

The increasing availability of phylogenetic information facilitates the use of evolutionary methods in community ecology to reveal the importance of evolution in the species assembly process. However, while several methods have been applied to a wide range of communities across different spatial scales with the purpose of detecting non-random phylogenetic patterns, the spatial aspects of phylogenetic community structure have received far less attention. Accordingly, the question for this study is: can point pattern analysis be used for revealing the phylogenetic structure of multi-species assemblages? We introduce a new individual-centered procedure for analyzing the scale-dependent phylogenetic structure of multi-species point patterns based on digitized field data. The method uses nested circular plots with increasing radii drawn around each individual plant and calculates the mean phylogenetic distance between the focal individual and all individuals located in the circular ring delimited by two successive radii. This scale-dependent value is then averaged over all individuals of the same species and the observed mean is compared to a null expectation with permutation procedures. The method detects particular radius values at which the point pattern of a single species exhibits maximum deviation from the expectation towards either phylogenetic aggregation or segregation. Its performance is illustrated using data from a grassland community in Hungary and simulated point patterns. The proposed method can be extended to virtually any distance function for species pairs, such as functional distances.

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Spatial analysis of phylogenetic community structure: New version of a classical method

10.7287/peerj.preprints.927v1 ◽

2015 ◽

Author(s):

Carlo Ricotta ◽

Eszter EA Ari ◽

Giuliano Bonanomi ◽

Francesco Giannino ◽

Duncan Heathfield ◽

...

Keyword(s):

Community Structure ◽

Spatial Scales ◽

Point Pattern ◽

Maximum Deviation ◽

Individual Plant ◽

Phylogenetic Distance ◽

Phylogenetic Structure ◽

Phylogenetic Community Structure ◽

Point Patterns ◽

Wide Range

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Variation in the components of Benthic community structure in a Coastal Lagoon as a function of Spatial Scale

Marine and Freshwater Research ◽

10.1071/mf9890079 ◽

1989 ◽

Vol 40 (1) ◽

pp. 79 ◽

Cited By ~ 18

Author(s):

A Hatcher

Keyword(s):

Community Structure ◽

Community Composition ◽

Coastal Lagoon ◽

Benthic Community ◽

Spatial Scales ◽

Small Scale ◽

Benthic Community Structure ◽

Extrinsic Factors ◽

Sessile Invertebrates ◽

Community Types

The perception of community structure is strongly related to the spatial resolution of data collection. To quantify variation in community structure at several spatial scales, the benthos was examined on the limestone substratum in a nearshore coastal lagoon. Community structure was described using a form of pattern analysis called correspondence analysis. Variance at three spatial scales was measured. These scales were described as: (I) between offshore and nearshore reefs (kilometres); (2) among areas on the nearshore reef-line (< 1 km); and (3) between community types on the nearshore reef-line (tens of metres and less). Organisms were classified according to higher taxa/functional classes. Parameters which varied between reef-lines included: (i) community composition determined using multivariate ordination, (ii) cover by calcareous and filamentous algae and (iii) abundance of seagrass and juvenile kelp (Ecklonia radiata). Among the areas on the nearshore reef-line, variance in community composition was due to the distribution of animals. There was a south to north gradient of increasing cover by encrusting animals and abundance of ascidians. Within the areas on the nearshore reef-line, there were two distinct community types characterized by macrophytic plants or sessile invertebrates. The major potential controls of the variation in benthic community structure were different at each of the spatial scales examined. The strong relationships between extrinsic factors and components of the communities suggested that the major potential controls were: (a) exposure to swell at the large scale (between reef-lines), (b) availability of food at the medium scale (within areas on the nearshore reef-line) and (c) biological interactions or responses to microtopography and light climate at the small scale (between and within communities on the nearshore reef-line).

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Mangrove benthic macrofauna: drivers of community structure and functional traits at multiple spatial scales

Marine Ecology Progress Series ◽

10.3354/meps13260 ◽

2020 ◽

Vol 638 ◽

pp. 25-38

Author(s):

RF Freitas ◽

PR Pagliosa

Keyword(s):

Community Structure ◽

Functional Traits ◽

Root Biomass ◽

Large Scale ◽

Spatial Scales ◽

Small Scale ◽

Functional Characteristics ◽

Multiple Spatial Scales ◽

Scale Factors ◽

Macrofaunal Community

Environmental processes acting at multiple spatial scales influence the structure and function of macrofaunal communities in marine habitats. However, the relative contributions of small- and large-scale factors in shaping faunal communities are still poorly understood. We investigated the relative contributions of climate, geophysical and soil properties, and forest structure on structural and functional characteristics of Brazilian coastal mangrove macrofauna. We found that macrofaunal community structure is mainly driven by large-scale factors, such as minimum air temperature and runoff, which significantly differed among the coastal settings investigated. Conversely, annelid assemblage functional traits were correlated with small-scale factors such as aboveground biomass, subsurface root biomass, soil bulk density, and soil phosphorus. Annelids with diversified and more complex functional traits (e.g. with respect to appendages, segments, parapodia) preferentially inhabited sites with low subsurface root biomass, while annelids with a slender body plan were more common at sites with dense root mats. Thus, while climate and geophysical conditions drive benthic macrofaunal community structure at larger spatial scales (i.e. coastal setting) in this system, vegetation and soil factors at smaller spatial scales (i.e. site) were more related to annelid functional characteristics.

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Burrow fumigation versus trapping for pocket gopher (Thomomys spp.) management: a comparison of efficacy and cost effectiveness

Wildlife Research ◽

10.1071/wr16037 ◽

2016 ◽

Vol 43 (5) ◽

pp. 389 ◽

Cited By ~ 2

Author(s):

Roger A. Baldwin ◽

Ryan Meinerz ◽

Steve B. Orloff

Keyword(s):

Cost Effectiveness ◽

Cost Effective ◽

Small Scale ◽

Management Approach ◽

Pocket Gopher ◽

Aluminum Phosphide ◽

Monitoring Method ◽

Pocket Gophers ◽

Multiple Treatment ◽

Treatment Type

Context Pocket gophers (Geomyidae) cause extensive damage to many crops throughout western North America. A variety of methods are available to manage these populations, but data are often lacking on their efficacy and especially their cost effectiveness. Additionally, little peer-reviewed data are available that compare multiple methods simultaneously. Aims We tested aluminum phosphide and pressurised exhaust using the Pressurised Exhaust Rodent Controller (PERC) as burrow fumigants, and compared them to trapping to determine which approach was most efficacious and cost effective. Methods We assessed the efficacy of aluminum phosphide, the PERC machine, and trapping through the use of the open-hole monitoring method after single and multiple treatments over multiple years. We determined material and labour costs for each treatment type and amortised this cost over 1250 days of application to determine which treatment type was most cost effective. Key results Aluminum phosphide had the shortest time for application, but we were able to make far more applications per day using the PERC machine, given our ability to treat multiple burrow systems at once with this machine. Trapping and aluminum phosphide were more efficacious than was the PERC machine. When costs were amortised over time, trapping was the most cost-effective approach even with longer application times, given high efficacy. Multiple treatment applications were needed to maximise the efficacy of management programs. Conclusions For small-scale management efforts, aluminum phosphide was a cost-effective and efficacious option. For a greater number of treatments, trapping was the most successful and cost effective. However, a modest increase in efficacy could make the PERC machine a preferred tool as well. We also stress that regardless of the management approach, multiple treatment applications will generally be needed to manage pocket gopher populations. Implications The present study provides growers with information needed to determine efficient and cost-effective methods for managing pocket gophers. This information can be used to craft an integrated pest-management approach to manage damaging pocket gopher populations.

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Spatial variation in the community structure of intertidal habitats at Macquarie Island (sub-Antarctic)

Antarctic Science ◽

10.1017/s0954102002000160 ◽

2002 ◽

Vol 14 (4) ◽

pp. 374-384 ◽

Cited By ~ 17

Author(s):

STEPHEN D.A. SMITH ◽

RODNEY D. SIMPSON

Keyword(s):

Community Structure ◽

Sampling Methods ◽

Spatial Scales ◽

Obvious Effect ◽

Community Patterns ◽

Macquarie Island ◽

Direct Sampling ◽

Durvillaea Antarctica ◽

Exposed Shore ◽

Intertidal Habitats

The shore environments of most sub-Antarctic islands have been described in a number of previous studies. However, there have been few attempts to quantify the variation in population and community patterns over different spatial scales. The objectives of this study were to provide an analysis of differences in the community structure of the biota of three exposed shore zones and of the macrofauna inhabiting holdfasts of the kelp Durvillaea antarctica across spatial scales of hundreds of metres, kilometres, and between a sheltered and exposed coast. Data were collected using a combination of quadrat, transect and direct sampling methods over the 1994–95 summer season. The results indicated that there were significant differences between coasts for some of the biotic variables in most of the habitats examined but that differences at the smaller spatial scales were more often significant. Thus, although wave exposure exerts an obvious effect on the shore biota of Macquarie Island, these effects are modified by other factors operating at smaller spatial scales. For the holdfast macrofauna, the overall patterns of community structure are likely to be due to the differential response of the component taxa to variation in holdfast volume and holdfast sediment content as well as other, currently undetermined factors.

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Small-scale effect of intertidal seagrass (Zostera muelleri) on meiofaunal abundance, biomass, and nematode community structure

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315410001645 ◽

2010 ◽

Vol 91 (3) ◽

pp. 579-591 ◽

Cited By ~ 21

Author(s):

Daniel Leduc ◽

P. Keith Probert

Keyword(s):

Organic Matter ◽

Community Structure ◽

Spatial Scales ◽

Nematode Community ◽

Habitat Characteristics ◽

Small Scale ◽

Seagrass Beds ◽

Seagrass Bed ◽

Feeding Groups ◽

The Impact

Seagrass beds are common features of coastal ecosystems worldwide, and their associated infauna are often more productive and diverse than in unvegetated habitats. Little is known, however, about the ecology of meiofaunal communities living in seagrass sediments. We compared the abundance and biomass of sediment meiofauna inside and outside an intertidalZostera muelleribed in southern New Zealand to assess the impact of seagrass cover on meiofaunal distribution. Nematode community structure, diversity, and feeding groups were also compared between habitats and sediment depths (0–2, 2–5 and 5–10 cm) to evaluate the effect of seagrass on nematode communities. Meiofaunal biomass was significantly higher inside than outside theZ. muelleribed, but secondary productivity inside the bed is likely to have been limited by the availability of labile organic matter. There were significant differences in nematode community structure between unvegetated, sparsely vegetated, and densely vegetated sites (102 m scale), as well as between sediment depths (cm scale). No significant differences were found in depth-integrated (0–10 cm) nematode diversity between sites, but vertical gradients in diversity differed between vegetated and unvegetated sites. Epistrate feeders were the most common feeding group in unvegetated sediments whereas most feeding groups were common inside the seagrass bed. Findings from this study indicate that seagrass beds can have a marked impact on infaunal structure and function over small spatial scales through their effect on sediment characteristics and organic matter input. Some unexpected trends observed in the present study, i.e. low meiofaunal biomass at the vegetated sites, and lower abundance of copepods inside than outside the seagrass bed, suggest that the nature of seagrass–invertebrate interactions may depend on habitat characteristics and the identity and ecology of species considered.

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Präzisions-Forstwirtschaft – was ist das? | Precision forestry – what's that?

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2007.0235 ◽

2007 ◽

Vol 158 (8) ◽

pp. 235-242 ◽

Cited By ~ 2

Author(s):

Hans Rudolf Heinimann

Keyword(s):

Business Processes ◽

Spatial Scales ◽

Supply Chain Coordination ◽

Sensor Technology ◽

Small Scale ◽

Soil Physics ◽

Coordination Problem ◽

Precision Engineering ◽

Precision Forestry ◽

And Control

The term «precision forestry» was first introduced and discussed at a conference in 2001. The aims of this paper are to explore the scientific roots of the precision concept, define «precision forestry», and sketch the challenges that the implementation of this new concept may present to practitioners, educators, and researchers. The term «precision» does not mean accuracy on a small scale, but instead refers to the concurrent coordination and control of processes at spatial scales between 1 m and 100 km. Precision strives for an automatic control of processes. Precision land use differs from precision engineering by the requirements of gathering,storing and managing spatio-temporal variability of site and vegetation parameters. Practitioners will be facing the challenge of designing holistic, standardized business processes that are valid for whole networks of firms,and that follow available standards (e.g., SCOR, WoodX). There is a need to educate and train forestry professionals in the areas of business process re-engineering, computer supported management of business transactions,methods of remote sensing, sensor technology and control theory. Researchers will face the challenge of integrating plant physiology, soil physics and production sciences and solving the supply chain coordination problem (SCCP).

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Dispersal and Land Cover Contribute to Pseudorabies Virus Exposure in Invasive Wild Pigs

EcoHealth ◽

10.1007/s10393-020-01508-6 ◽

2021 ◽

Author(s):

Felipe A. Hernández ◽

Amanda N. Carr ◽

Michael P. Milleson ◽

Hunter R. Merrill ◽

Michael L. Avery ◽

...

Keyword(s):

Land Cover ◽

Disease Transmission ◽

Wildlife Conservation ◽

Pseudorabies Virus ◽

Spatial Scales ◽

Information Criterion ◽

Small Scale ◽

Wild Pigs ◽

Bacterial Agent ◽

Open Canopy

AbstractWe investigated the landscape epidemiology of a globally distributed mammal, the wild pig (Sus scrofa), in Florida (U.S.), where it is considered an invasive species and reservoir to pathogens that impact the health of people, domestic animals, and wildlife. Specifically, we tested the hypothesis that two commonly cited factors in disease transmission, connectivity among populations and abundant resources, would increase the likelihood of exposure to both pseudorabies virus (PrV) and Brucella spp. (bacterial agent of brucellosis) in wild pigs across the Kissimmee Valley of Florida. Using DNA from 348 wild pigs and sera from 320 individuals at 24 sites, we employed population genetic techniques to infer individual dispersal, and an Akaike information criterion framework to compare candidate logistic regression models that incorporated both dispersal and land cover composition. Our findings suggested that recent dispersal conferred higher odds of exposure to PrV, but not Brucella spp., among wild pigs throughout the Kissimmee Valley region. Odds of exposure also increased in association with agriculture and open canopy pine, prairie, and scrub habitats, likely because of highly localized resources within those land cover types. Because the effect of open canopy on PrV exposure reversed when agricultural cover was available, we suggest that small-scale resource distribution may be more important than overall resource abundance. Our results underscore the importance of studying and managing disease dynamics through multiple processes and spatial scales, particularly for non-native pathogens that threaten wildlife conservation, economy, and public health.

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FORMULATION OF THE HEAT CONDUCTION EQUATION FOR HETEROGENEOUS MEDIA WITH MULTIPLE SPATIAL SCALES USING REITERATED HOMOGENIZATION

Revista de Engenharia Térmica ◽

10.5380/reterm.v15i1.62165 ◽

2016 ◽

Vol 15 (1) ◽

pp. 96

Author(s):

E. Iglesias-Rodríguez ◽

M. E. Cruz ◽

J. Bravo-Castillero ◽

R. Guinovart-Díaz ◽

R. Rodríguez-Ramos ◽

...

Keyword(s):

Heat Conduction ◽

Small Parameter ◽

Heat Conduction Equation ◽

Heterogeneous Media ◽

Spatial Scales ◽

Conduction Equation ◽

Small Scale ◽

Multiple Spatial Scales ◽

Effective Coefficients ◽

Reiterated Homogenization

Heterogeneous media with multiple spatial scales are finding increased importance in engineering. An example might be a large scale, otherwise homogeneous medium filled with dispersed small-scale particles that form aggregate structures at an intermediate scale. The objective in this paper is to formulate the strong-form Fourier heat conduction equation for such media using the method of reiterated homogenization. The phases are assumed to have a perfect thermal contact at the interface. The ratio of two successive length scales of the medium is a constant small parameter ε. The method is an up-scaling procedure that writes the temperature field as an asymptotic multiple-scale expansion in powers of the small parameter ε . The technique leads to two pairs of local and homogenized equations, linked by effective coefficients. In this manner the medium behavior at the smallest scales is seen to affect the macroscale behavior, which is the main interest in engineering. To facilitate the physical understanding of the formulation, an analytical solution is obtained for the heat conduction equation in a functionally graded material (FGM). The approach presented here may serve as a basis for future efforts to numerically compute effective properties of heterogeneous media with multiple spatial scales.

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