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Dryad

Root foraging strategies and niche segregation of three Mediterranean shrub species

Cite this dataset

Cabal, Ciro; Valladares, Fernando; Pacala, Stephen (2024). Root foraging strategies and niche segregation of three Mediterranean shrub species [Dataset]. Dryad. https://doi.org/10.5061/dryad.brv15dvhz

Abstract

Shrubs are usually adapted to stressful environments in which soil resources are limited, and thus, roots are fundamental for their biological success. However, root measures are challenging to collect, especially in field conditions and at the individual level. For this study, we collected data on the three-dimensional distribution of fine root biomass of twenty-three individuals belonging to three shrub species in a Mediterranean shrubland in Central Spain: gum rockrose (Cistus ladanifer L.), rosemary (Salvia rosmarinus Schleid.), and hairy-fruited broom (Cytisus striatus [Hill] Rothm). Our goal was to determine the soil-foraging strategies adopted by the plants. We hypothesized that plants would show stabilizing niche differences explaining the high plant biodiversity characteristic of Mediterranean shrublands and that they would follow the game theory model’s prediction of exploitative segregation of roots behaving territorially but also over-proliferating roots close to their stem and engaging in a root tragedy of the commons. We found that two-thirds to three-fourths of the biomass was belowground, and the system's productivity was roughly 500-600 g C m-2 y-1. Only rosemary plants competed with neighbors following the exploitative segregation predictions. Broom plants had the shallowest and most widespread root systems but significantly reduced their root range toward competing neighbors. Gum rockrose presented deep, narrow root systems avoiding extensive overlap with neighbors but did not appear to respond to competitive pressure levels. Shrubs appeared to stratify their roots at different soil depths, supporting the niche segregation hypothesis.

README: Root foraging strategies and niche segregation of three Mediterranean shrub species

https://doi.org/10.5061/dryad.brv15dvhz

This dataset includes information about aboveground and belowground biomass and plant structure of individuals belonging to three species, rosemary (Salvia rosmarinus Schleid., Lamiaceae), gum rockrose (Cistus ladanifer L., Cistaceae), and hairy-fruited broom (Cytisus striatus [Hill] Rothm, Fabaceae), collected in a Mediterranean shrubland in Central Spain. This dataset is organized into three data sheets in format .txt. First, it includes information about plant individuals of rosemary and rockrose in the same study site of which we measured aboveground labile biomass allocation (.e., reproductive allocation and leaf and branch turnover) (D-CAN-plants). Second, it includes, for another subset of plants of the same species for which we measured the root density distribution in soil, information about each plant individual, such as aboveground weight or crown area, or its coordinates within the sampling plot (R-CAN-plants). Third, in includes gereal information about each soil sample extracted in each sampling plot such as the coordinates of the sample, the soil volume, the stone and gravel volume, and the total root weight in the sample (R-CAN-cores). Finally, the diameter and dry weight of each root fragment extracted in each sample and its linkage to an individual plant from the same plot (R-CAN-roots). This individual-level root biomass indentification information was obtained from mixed root samples injecting different color dyes to the plants from aboveground, so that the roots were stained, as described in detail in Cabal et al., 2022 (https://doi.org/10.1007/s11104-022-05657-1).

Description of the data and file structure

This data set includes four data sheets:

D-CAN-plants: Labile biomass allocation of twelve rosemary plants (Sr) and twelve rockrose plants (Cl).

  • plant - Code for the plant
  • sp - Code for the species

Data collected at the begining and end of the sampling year:

  • totH - Total plant height (m)
  • CA - Crown area (m^2)
  • StemD - Stem diameter at the ground level (cm)
  • TrayArea - Area of collecting biomass trays (m^2)

Data collected every two month for each plant.

  • PM - Photosynthetic material collected in litter (g)
  • NPM - Non photosynthetic material collected in litter (g)
  • RepM - Reproductive material collected in litter (g)

R-CAN-cores: Gereral information about each soil sample extacted.

  • sample - Code for the sample (stratified sector of the core)
  • plot - Code for the plot
  • core - Code for the core
  • depth - maximum depth of the sample within the core
  • cX - x coordinate of the core in the plot (m)
  • cY - y coordinate of the core in the plot (m)
  • cZgr - z coordinate of the core in the plot (m) (considering the slope of the plot and using the highest point of the plot as z=0)
  • cZ - z coordinate of the sample in the plot (m) based in depth and cZgr
  • Vol - Total volume of the sample (cm^3)
  • stone - Non-rooting volume in the sample (stone and gravel) (cm^3)
  • SieveR - Total roots from the core recupareted by siefting (g)
  • FloatR - Total roots from the core recupareted by floatation (g)

R-CAN-plants: General information about the targeted plants for the root measures

  • plant - Code for the plant
  • plot - Code for the plot
  • marker - Code for the marker (Y-yellow, P-purple, R-red, B-blue, G-green)
  • sp - Code for the species
  • totH - Total plant height (m)
  • CA - Crown area (m^2)
  • PM - Dry biomass of standing photosynthetic material (g)
  • NPM - Dry biomass of standing non photosynthetic material (g)
  • pX - x coordinate of the insertion point of the plant in the plot (m)
  • pY - y coordinate of the insertion point of the plant in the plot (m)
  • pZ - z coordinate of the insertion point of the plant in the plot (m)
  • totA - Harwood area measured at the ground level (cm^2)
  • sapA - Sapwood area measured at the ground level (cm^2)
  • age - Age of the plant (yr)
  • dstem - Stem diameter at the ground level (cm)

R-CAN-roots: Data about the roots collected from each soil sample

  • sievecod - Code for the root fragment (including ramifications)
  • root - Code for the root fragment (a root fragment with a sievecod can be fragmented in different diameters when ramified)
  • sample - Code for the soil sample (plot-core-depth)
  • plot - Code for the plot
  • core - Code for the core
  • depth - maximum depth of the sample within the core
  • Droot - Diameter of the root fragment (mm)
  • Wroot - Dry weight of the root sample (mg)
  • IdMet - Method for identifying the root at the individual level (staining for all cases)
  • marker - Code for the marker in the root (Y-yellow, P-purple, R-red, B-blue, G-green, NA-none)
  • DetCode - Code for the detetion method of the marker (vis-visual, D5min-5 min dissolution in water, D2h- dissolution 2h in water, D24h disolution 24h in water)
  • Link - Was the linkage of the root fragment to an individual successful?

Missing data code: NA

Code/Software

The code used to analyze the data using the software R will be shared with any interested researcher upon request to the corresponding author.

Funding

Princeton University, Carbon Mitigation Initiative - HMEI