Connecting regional-scale tree distribution models with seed dispersal kernels

Abstract. The top-of-atmosphere (TOA) radiative fluxes are critical components to advancing our understanding of the Earth's radiative energy balance, radiative effects of clouds and aerosols, and climate feedback. The Clouds and the Earth's Radiant Energy System (CERES) instruments provide broadband shortwave and longwave radiance measurements. These radiances are converted to fluxes by using scene-type-dependent angular distribution models (ADMs). This paper describes the next-generation ADMs that are developed for Terra and Aqua using all available CERES rotating azimuth plane radiance measurements. Coincident cloud and aerosol retrievals, and radiance measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS), and meteorological parameters from Goddard Earth Observing System (GEOS) data assimilation version 5.4.1 are used to define scene type. CERES radiance measurements are stratified by scene type and by other parameters that are important for determining the anisotropy of the given scene type. Anisotropic factors are then defined either for discrete intervals of relevant parameters or as a continuous functions of combined parameters, depending on the scene type. Significant differences between the ADMs described in this paper and the existing ADMs are over clear-sky scene types and polar scene types. Over clear ocean, we developed a set of shortwave (SW) ADMs that explicitly account for aerosols. Over clear land, the SW ADMs are developed for every 1° latitude × 1° longitude region for every calendar month using a kernel-based bidirectional reflectance model. Over clear Antarctic scenes, SW ADMs are developed by accounting the effects of sastrugi on anisotropy. Over sea ice, a sea-ice brightness index is used to classify the scene type. Under cloudy conditions over all surface types, the longwave (LW) and window (WN) ADMs are developed by combining surface and cloud-top temperature, surface and cloud emissivity, cloud fraction, and precipitable water. Compared to the existing ADMs, the new ADMs change the monthly mean instantaneous fluxes by up to 5 W m−2 on a regional scale of 1° latitude × 1° longitude, but the flux changes are less than 0.5 W m−2 on a global scale.

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Landscape structure shapes carnivore-mediated seed dispersal kernels

Landscape Ecology ◽

10.1007/s10980-015-0283-4 ◽

2015 ◽

Vol 31 (4) ◽

pp. 731-743 ◽

Cited By ~ 8

Author(s):

José M. Herrera ◽

Isa de Sá Teixeira ◽

Javier Rodríguez-Pérez ◽

António Mira

Keyword(s):

Seed Dispersal ◽

Landscape Structure ◽

Dispersal Kernels

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Regional-scale groundwater flow in a Canadian Shield setting

Canadian Geotechnical Journal ◽

10.1139/t09-017 ◽

2009 ◽

Vol 46 (7) ◽

pp. 813-827 ◽

Cited By ~ 7

Author(s):

Jonathan F. Sykes ◽

Stefano D. Normani ◽

Mark R. Jensen ◽

Edward A. Sudicky

Keyword(s):

Groundwater Flow ◽

Surface Topography ◽

Regional Scale ◽

Three Dimensional ◽

Complex Surface ◽

Crystalline Rock ◽

Canadian Shield ◽

Water Drainage ◽

Distribution Models ◽

Matrix Permeability

A three-dimensional numerical analysis of a 5734 km2 watershed situated in the Canadian Shield has been conducted to illustrate aspects of regional-scale groundwater flow in a crystalline rock setting. An essential requirement of the analysis is the preservation and accurate description of the complex topography, surface water drainage network, groundwater salinity distribution, and permeability distributions. The postglacial evolution of the groundwater flow system was investigated using the finite difference model SWIFT-III. Robustness was assessed by exploring the sensitivity of groundwater flow to topography, variable matrix permeability distribution models, pore-water salinity, and the dissipation of elevated initial pore pressures that result from ice that overlaid the watershed in the last glacial period. Groundwater flow analyses indicate that freshwater heads in all model layers are highly correlated with the complex surface topography such that the transition from zones of groundwater recharge to zones of discharge occurs over distances that can be relatively short. Shallow flow to a depth of tens of metres dominates the overall water balance, and the length of flow paths is relatively short. The analyses of this study indicate that the flow in deeper rock is not regional but rather is a subdued reflection of the local-scale surface topography.

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Co-occurrence variation explains the low host dependence of ambrosia beetles along altitude gradients in SW China

10.21203/rs.3.rs-845818/v1 ◽

2021 ◽

Author(s):

Fang Luo ◽

LINGZENG MENG ◽

Jian Wang ◽

Yan-Hong Liu

Keyword(s):

Temporal Dynamics ◽

Hierarchical Modeling ◽

Species Turnover ◽

Regional Scale ◽

Biotic Interactions ◽

Ambrosia Beetle ◽

Minor Role ◽

Climatic Gradient ◽

Distribution Models ◽

Ambrosia Beetles

Abstract Background Separation of biotic and abiotic impacts on species diversity distribution patterns across a significant climatic gradient is a challenge in the study of diversity maintenance mechanisms. The basic task is to reconcile scale-dependent effects of abiotic and biotic processes on species distribution models. However, Eltonian noise hypothesis predicted that the effects of biotic interactions will be averaged out at macroscales, and there are many empirical observations that biotic interactions would constrain species distributions at micro-ecological scales. Here, we used a hierarchical modeling method to detect the host specificities of ambrosia beetles (Scolytinae and Platypodinae) with their dependent tree communities across a steep climatic gradient, which was embedded within a relatively homogenous spatial niche. Results Species turnover of both trees and ambrosia beetles have a relatively similar pattern, characterized by the climatic proxy at a regional scale, but not at local scales. This pattern confirmed the Eltonian noise hypothesis wherein emphasis was on influences of macro-climate on local biotic interactions between trees and hosted ambrosia beetle communities, whereas local biotic relations, represented by host specificity dependence, were regionally conserved. Conclusions At a confined spatial scale, cross-taxa comparisons of co-occurrence highlighted the importance of the organism’s dispersal. The effects of tree abundance and phylogeny diversity on ambrosia beetle diversity were, to a large extent, indirect, operating via changes in ambrosia beetle abundance through spatial and temporal dynamics of resources distribution. Tree host dependence plays a minor role on the hosted ambrosia beetle community in this concealed wood decomposing interacting system.

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Different drivers, common mechanism; the distribution of a reef fish is restricted by local-scale oxygen and temperature constraints on aerobic metabolism

Conservation Physiology ◽

10.1093/conphys/coaa090 ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Murray I Duncan ◽

Nicola C James ◽

Warren M Potts ◽

Amanda E Bates

Keyword(s):

South African ◽

Reef Fish ◽

Regional Scale ◽

Marine Organisms ◽

Hypoxia Tolerance ◽

Common Mechanism ◽

Local Conservation ◽

Management Decisions ◽

Distribution Models ◽

Temperature Range

Abstract The distributions of ectothermic marine organisms are limited to temperature ranges and oxygen conditions that support aerobic respiration, quantified within the metabolic index (ϕ) as the ratio of oxygen supply to metabolic oxygen demand. However, the utility of ϕ at local scales and across heterogenous environments is unknown; yet, these scales are often where actionable management decisions are made. Here, we test if ϕ can delimit the entire distribution of marine organisms when calibrated across an appropriate temperature range and at local scales (~10 km) using the endemic reef fish, Chrysoblephus laticeps, which is found in the highly heterogenous temperature and oxygen environment along the South African coastal zone, as a model species. In laboratory experiments, we find a bidirectional (at 12°C) hypoxia tolerance response across the temperature range tested (8 to 24°C), permitting a piecewise calibration of ϕ. We then project this calibrated ϕ model through temperature and oxygen data from a high spatial resolution (11 to 13 km) ocean model for the periods 2005 to 2009 and 2095 to 2099 to quantify various magnitudes of ϕ across space and time paired with complementary C. laticeps occurrence points. Using random forest species distribution models, we quantify a critical ϕ value of 2.78 below which C. laticeps cannot persist and predict current and future distributions of C. laticeps in line with already observed distribution shifts of other South African marine species. Overall, we find that C. laticeps’ distribution is limited by increasing temperatures towards its warm edge but by low oxygen availability towards its cool edge, which is captured within ϕ at fine scales and across heterogenous oxygen and temperature combinations. Our results support the application of ϕ for generating local- and regional-scale predictions of climate change effects on organisms that can inform local conservation management decisions.

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Understanding the ecological niche to elucidate spatial strategies of the southernmost Tupinambis lizards

Amphibia-Reptilia ◽

10.1163/15685381-00002917 ◽

2013 ◽

Vol 34 (4) ◽

pp. 551-565 ◽

Cited By ~ 14

Author(s):

Sofía Lanfri ◽

Valeria Di Cola ◽

Sergio Naretto ◽

Margarita Chiaraviglio ◽

Gabriela Cardozo

Keyword(s):

Species Distribution ◽

Evolutionary Biology ◽

Species Distribution Models ◽

Regional Scale ◽

Distribution Patterns ◽

Niche Differentiation ◽

Ecological Niches ◽

Distribution Models ◽

Interspecific Differences ◽

Spatial Strategies

Understanding factors that shape ranges of species is central in evolutionary biology. Species distribution models have become important tools to test biogeographical, ecological and evolutionary hypotheses. Moreover, from an ecological and evolutionary perspective, these models help to elucidate the spatial strategies of species at a regional scale. We modelled species distributions of two phylogenetically, geographically and ecologically close Tupinambis species (Teiidae) that occupy the southernmost area of the genus distribution in South America. We hypothesized that similarities between these species might have induced spatial strategies at the species level, such as niche differentiation and divergence of distribution patterns at a regional scale. Using logistic regression and MaxEnt we obtained species distribution models that revealed interspecific differences in habitat requirements, such as environmental temperature, precipitation and altitude. Moreover, the models obtained suggest that although the ecological niches of Tupinambis merianae and T. rufescens are different, these species might co-occur in a large contact zone. We propose that niche plasticity could be the mechanism enabling their co-occurrence. Therefore, the approach used here allowed us to understand the spatial strategies of two Tupinambis lizards at a regional scale.

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Regeneration patterns among bird-dispersed plants in a fragmented Afrotropical forest, south-east Kenya

Journal of Tropical Ecology ◽

10.1017/s0266467402002092 ◽

2002 ◽

Vol 18 (1) ◽

pp. 143-149 ◽

Cited By ~ 6

Author(s):

MWANGI GITHIRU ◽

LEON BENNUN ◽

LUC LENS

Keyword(s):

Habitat Fragmentation ◽

Seed Dispersal ◽

Plant Species ◽

Foraging Behaviour ◽

Random Pattern ◽

Tropical Plants ◽

Tree Distribution ◽

Adult Tree ◽

Tree Seeds ◽

Avian Frugivores

Fruit-eating birds play an important role in the seed dispersal of many tropical plants (e.g. Herrera 1984), and the foraging behaviour of avian frugivores may affect their seed-dispersal capabilities (Loiselle & Blake 1999,Schupp 1993, Traveset 1994). For instance,shorter visits tend to produce less clumped seed distributions (Graham et al. 1995). Also,avian frugivores often feed on the fruits of several plant species over short periods of time (Herrera 1984, 1988a; Levey et al. 1994) in some non-random pattern (Herrera 1998). This potentially produces a predictable spatial pattern of the dispersed seeds (White & Stiles 1990). Forest destruction leads to fragmentation and degradation of the remaining habitats, which may influence patterns of adult tree distribution if the production, predation, dispersal, and/or regeneration of tree seeds is affected (Harrington et al. 1997). If dispersal of avian frugivores is disrupted by habitat fragmentation, plant species might face reduced regeneration, or even local extinction if they depend on a single, locally extinct disperser (Kellman et al. 1996). Increased predation of seeds and regenerating plants in the edges and gaps may also directly reduce regeneration rates (Corlett & Turner 1997, Harrington et al. 1997, Schupp 1988).

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Exploring the Interplay Between Local and Regional Drivers of Distribution of a Subterranean Organism

Diversity ◽

10.3390/d11080119 ◽

2019 ◽

Vol 11 (8) ◽

pp. 119 ◽

Cited By ~ 2

Author(s):

Stefano Mammola ◽

Shlomi Aharon ◽

Merav Seifan ◽

Yael Lubin ◽

Efrat Gavish-Regev

Keyword(s):

Species Distribution ◽

Spatial Scales ◽

Abiotic Factors ◽

Regional Scale ◽

Regional Distribution ◽

Ecological Factors ◽

Local Scale ◽

Model Systems ◽

Mean Annual Temperature ◽

Distribution Models

Caves are excellent model systems to study the effects of abiotic factors on species distributions due to their selective conditions. Different ecological factors have been shown to affect species distribution depending on the scale of analysis, whether regional or local. The interplay between local and regional factors in explaining the spatial distribution of cave-dwelling organisms is poorly understood. Using the troglophilic subterranean spider Artema nephilit (Araneae: Pholcidae) as a model organism, we investigated whether similar environmental predictors drive the species distribution at these two spatial scales. At the local scale, we monitored the abundance of the spiders and measured relevant environmental features in 33 caves along the Jordan Rift Valley. We then extended the analysis to a regional scale, investigating the drivers of the distribution using species distribution models. We found that similar ecological factors determined the distribution at both local and regional scales for A. nephilit. At a local scale, the species was found to preferentially occupy the outermost, illuminated, and warmer sectors of caves. Similarly, mean annual temperature, annual temperature range, and solar radiation were the most important drivers of its regional distribution. By investigating these two spatial scales simultaneously, we showed that it was possible to achieve an in-depth understanding of the environmental conditions that governs subterranean species distribution.

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Integrating anthropogenic factors into regional‐scale species distribution models—A novel application in the imperiled sagebrush biome

Global Change Biology ◽

10.1111/gcb.14728 ◽

2019 ◽

Vol 25 (11) ◽

pp. 3844-3858 ◽

Cited By ~ 3

Author(s):

Juan M. Requena‐Mullor ◽

Kaitlin C. Maguire ◽

Douglas J. Shinneman ◽

Timothy Trevor Caughlin

Keyword(s):

Species Distribution ◽

Species Distribution Models ◽

Regional Scale ◽

Anthropogenic Factors ◽

Distribution Models

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A 1-km global dataset of historical (1979–2017) and future (2020–2100) Köppen-Geiger climate classification and bioclimatic variables

10.5194/essd-2021-186 ◽

2021 ◽

Author(s):

Diyang Cui ◽

Shunlin Liang ◽

Dongdong Wang ◽

Zheng Liu

Keyword(s):

Climate Change ◽

Regional Scale ◽

Climatic Conditions ◽

Future Climate ◽

Distribution Models ◽

Climate Classification ◽

Climate Change Research ◽

Climate Zones ◽

Bioclimatic Variables

Abstract. The Köppen-Geiger classification scheme provides an effective and ecologically meaningful way to characterize climatic conditions and has been widely applied in climate change studies. Significant changes in Köppen climates have been observed and projected in the recent two centuries. Current accuracy, temporal coverage, spatial and temporal resolution of historical and future climate classification maps cannot sufficiently fulfil the current needs of climate change research. Comprehensive assessment of climate change impacts requires a more accurate depiction of fine-grained climatic conditions and continuous long-term time coverage. Here, we present a series of improved 1-km Köppen-Geiger climate classification maps for ten historical periods in 1979–2017 and four future periods in 2020–2099 under RCP2.6, 4.5, 6.0, and 8.5. The historical maps are derived from multiple downscaled observational datasets and the future maps are derived from an ensemble of bias-corrected downscaled CMIP5 projections. In addition to climate classification maps, we calculate 12 bioclimatic variables at 1-km resolution, providing detailed descriptions of annual averages, seasonality, and stressful conditions of climates. The new maps offer higher classification accuracy and demonstrate the ability to capture recent and future projected changes in spatial distributions of climate zones. On regional and continental scales, the new maps show accurate depictions of topographic features and correspond closely with vegetation distributions. We also provide a heuristic application example to detect long-term global-scale area changes of climate zones. This high-resolution dataset of Köppen-Geiger climate classification and bioclimatic variables can be used in conjunction with species distribution models to promote biodiversity conservation and to analyze and identify recent and future interannual or interdecadal changes in climate zones on a global or regional scale. The dataset referred to as KGClim, is publicly available at http://doi.org/10.5281/zenodo.4546140 for historical climate and http://doi.org/10.5281/zenodo.4542076 for future climate.

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