- P.A. Jansen (1)
- F. Langevelde van (1)
- S.W. Lyon (1)
- Jeffrey N. Peereboom (1)
- L. Nyberg (1)
- Sophie P. Ewert (1)
- Dries P.J. Kuijper (1)
- H.H.T. Prins (1)
- A. Rinaldo (1)
- A. Rodhe (1)
- P.J.J.F. Torfs (1)
- P.A. Troch (1)
- R. Uijlenhoet (1)
- Y. Velde van der (3)
- M.J.A. Weterings (1)
- S.E. Wieren van (1)
- S.E.A.T.M. Zee van der (2)
Data from: Implications of shared predation for space use in two sympatric leporids
Weterings, M.J.A. ; Ewert, Sophie P. ; Peereboom, Jeffrey N. ; Kuipers, Henry J. ; Kuijper, Dries P.J. ; Prins, H.H.T. ; Jansen, P.A. ; Langevelde, F. van; Wieren, S.E. van - \ 2019
alternative prey - habitat characteristics - habitat riskiness - residence time - space race - vegetation structure - Lepus europaeus - Oryctolagus cuniculus - Vulpes vulpes
Spatial variation in habitat riskiness has a major influence on the predator–prey space race. However, the outcome of this race can be modulated if prey shares enemies with fellow prey (i.e., another prey species). Sharing of natural enemies may result in apparent competition, and its implications for prey space use remain poorly studied. Our objective was to test how prey species spend time among habitats that differ in riskiness, and how shared predation modulates the space use by prey species. We studied a one‐predator, two‐prey system in a coastal dune landscape in the Netherlands with the European hare (Lepus europaeus) and European rabbit (Oryctolagus cuniculus) as sympatric prey species and red fox (Vulpes vulpes) as their main predator. The fine‐scale space use by each species was quantified using camera traps. We quantified residence time as an index of space use. Hares and rabbits spent time differently among habitats that differ in riskiness. Space use by predators and habitat riskiness affected space use by hares more strongly than space use by rabbits. Residence time of hare was shorter in habitats in which the predator was efficient in searching or capturing prey species. However, hares spent more time in edge habitat when foxes were present, even though foxes are considered ambush predators. Shared predation affected the predator–prey space race for hares positively, and more strongly than the predator–prey space race for rabbits, which were not affected. Shared predation reversed the predator–prey space race between foxes and hares, whereas shared predation possibly also released a negative association and promoted a positive association between our two sympatric prey species. Habitat riskiness, species presence, and prey species’ escape mode and foraging mode (i.e., central‐place vs. noncentral‐place forager) affected the prey space race under shared predation.
Consequences of mixing assumptions for time-variable travel time distributions
Velde, Y. van der; Heidbüchel, I. ; Lyon, S.W. ; Nyberg, L. ; Rodhe, A. ; Bishop, K. ; Troch, P.A. - \ 2015
Hydrological Processes 29 (2015)16. - ISSN 0885-6087 - p. 3460 - 3474.
solute transport - stream chemistry - stable-isotopes - residence time - transit times - water storage - catchment - model - age - dispersion
The current generation of catchment travel time distribution (TTD) research, integrating nearly three decades of work since publication of Water's Journey from Rain to Stream, seeks to represent the full distribution in catchment travel times and its temporal variability. Here, we compare conceptualizations of increasing complexity with regards to mixing of water storages and evaluate how these assumptions influence time-variable TTD estimates for two catchments with contrasting climates: the Gårdsjön catchment in Sweden and the Marshall Gulch catchment in Arizona, USA. Our results highlight that, as long as catchment TTDs cannot be measured directly but need to be inferred from input-output signals of catchments, the inferred catchment TTDs depend strongly on the underlying assumptions of mixing within a catchment. Furthermore, we found that the conceptualization of the evapotranspiration flux strongly influences the inferred travel times of stream discharge. For the wet and forested Gårdsjön catchment in Sweden, we inferred that evapotranspiration most likely resembles a completely mixed sample of the water stored in the catchment; however, for the drier Marshall Gulch catchment in Arizona, evapotranspiration predominantly contained the younger water stored in the catchment. For the Marshall Gulch catchment, this higher probability for young water in evapotranspiration resulted in older water in the stream compared to travel times inferred with assumptions of complete mixing. New observations that focus on the TTD of the evapotranspiration flux and the actual travel time of water through a catchment are necessary to improve identification of mixing and consequently travel times of stream water. Copyright © 2014 John Wiley & Sons, Ltd.
Chloride circulation in a lowland catchment and the formulation of transport by travel time distributions
Bennettin, P. ; Velde, Y. van der; Zee, S.E.A.T.M. van der; Rinaldo, A. ; Botter, G. - \ 2013
Water Resources Research 49 (2013)8. - ISSN 0043-1397 - p. 4619 - 4632.
flow route contributions - residence time - upland catchments - water - scale - soil - models - conceptualization - streamwater - hydrology
 Travel times are fundamental catchment descriptors that blend key information about storage, geochemistry, flow pathways and sources of water into a coherent mathematical framework. Here we analyze travel time distributions (TTDs) (and related attributes) estimated on the basis of the extensive hydrochemical information available for the Hupsel Brook lowland catchment in the Netherlands. The relevance of the work is perceived to lie in the general importance of characterizing nonstationary TTDs to capture catchment transport properties, here chloride flux concentrations at the basin outlet. The relative roles of evapotranspiration, water storage dynamics, hydrologic pathways and mass sources/sinks are discussed. Different hydrochemical models are tested and ranked, providing compelling examples of the improved process understanding achieved through coupled calibration of flow and transport processes. The ability of the model to reproduce measured flux concentrations is shown to lie mostly in the description of nonstationarities of TTDs at multiple time scales, including short-term fluctuations induced by soil moisture dynamics in the root zone and long-term seasonal dynamics. Our results prove reliable and suggest, for instance, that drastically reducing fertilization loads for one or more years would not result in significant permanent decreases in average solute concentrations in the Hupsel runoff because of the long memory shown by the system. Through comparison of field and theoretical evidence, our results highlight, unambiguously, the basic transport mechanisms operating in the catchment at hand, with a view to general applications.
Quantifying catchment-scale mixing and its effect on time-varying travel time distributions
Velde, Y. van der; Torfs, P.J.J.F. ; Zee, S.E.A.T.M. van der; Uijlenhoet, R. - \ 2012
Water Resources Research 48 (2012)6. - ISSN 0043-1397 - 13 p.
flow route contributions - solute transport - transit-time - lowland catchment - residence time - steady-state - hydrology - model - soil - discharge
Travel time distributions are often used to characterize catchment discharge behavior, catchment vulnerability to pollution and pollutant loads from catchments to downstream waters. However, these distributions vary with time because they are a function of rainfall and evapotranspiration. It is important to account for these variations when the time scale of interest is smaller than the typical time-scale over which average travel time distributions can be derived. Recent studies have suggested that subsurface mixing controls how rainfall and evapotranspiration affect the variability in travel time distributions of discharge. To quantify this relation between subsurface mixing and dynamics of travel time distributions, we propose a new transformation of travel time that yields transformed travel time distributions, which we call Storage Outflow Probability (STOP) functions. STOP functions quantify the probability for water parcels in storage to leave a catchment via discharge or evapotranspiration. We show that this is equal to quantifying mixing within a catchment. Compared to the similar Age function introduced by Botter et al. (2011), we show that STOP functions are more constant in time, have a clearer physical meaning and are easier to parameterize. Catchment-scale STOP functions can be approximated by a two-parameter beta distribution. One parameter quantifies the catchment preference for discharging young water; the other parameter quantifies the preference for discharging old water from storage. Because of this simple parameterization, the STOP function is an innovative tool to explore the effects of catchment mixing behavior, seasonality and climate change on travel time distributions and the related catchment vulnerability to pollution spreading.