Disturbances in drylands: Interactions among herbivory, drought, and termite activity in savanna plant communities
Data files
Mar 19, 2025 version files 25.67 MB
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Hits_OMWC_20stns_cont_final.csv
169.07 KB
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PA_OMWC_50stns_cont_final.csv
25.50 MB
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README.md
5.75 KB
Abstract
Climate models predict increases in the frequency and intensity of extreme-weather events. The impacts of these events may be modulated by biotic agents in unpredictable ways, yet few experiments cover sufficient spatiotemporal scales to measure the interactive effects of multiple extreme events. We used 15 years of a 28-year experiment spanning several significant droughts to investigate how rainfall, large herbivores, and soil-engineering termites affect understory vegetation in a semi-arid savanna. Herbivory was the dominant influence on community structure—decreasing cover, increasing species richness, and favouring occurrence of annuals relative to perennials—but these effects were contingent on rainfall and termitaria in non-additive (hence unpredictable) ways. A separate experiment affirmed that resource supplementation does not straightforwardly compensate for herbivory effects.
Synthesis: Our study highlights the potency of top-down forcing in African savannas. It suggests impressive robustness to drought and underscores the value of multi-decadal experiments for studying interactions among multiple drivers of ecosystem dynamics.
https://doi.org/10.5061/dryad.18931zd7q
Description of the data and file structure
These data were collected at the Kenya Long-term Herbivore Exclusion Experiment (KLEE) and were used to study the effects of herbivores, rainfall, and termite mounds on African savanna understory vegetation.
Files and variables
File: Hits_OMWC_20stns_cont_final.csv
Description: Understory plant pin frame pin hit data in the fenced (‘O’) and unfenced (‘MWC’) treatments of KLEE at 20 sampling stations.
Variables
- Date: Sampling date to closest month (YYYY-MM-DD).
- Survey: Numerical survey ID.
- Block: Replicate block (N=north, C=central, S=South).
- Treatment: Herbivore treatment (O=fenced, MWC=unfenced).
- Row: Row ID of sampling grid.
- Column: Column ID of sampling grid.
- Station: Sampling station ID (RowColumn).
- Plot: Plot (Block-Treatment).
- unqID: Unique sampling station ID (Block-Treatment-Sampling station)
- Hits: Total number of pin hits of all species.
- dT: Distance to termite mound (m).
- cum4mo: Cumulative 4-month antecedent rainfall (mm).
- cum4mo_t2: Cumulative 4-month antecedent rainfall of previous year (mm).
File: PA_OMWC_50stns_cont_final.csv
Description: Understory plant quadrat presence-absence data in the fenced (‘O’) and unfenced (‘MWC’) treatments of KLEE at 20 sampling stations.
Variables
- Date: Sampling date to the closest month (YYYY-MM-DD).
- Block: Replicate block (N=north, C=central, S=South).
- Treatment: Herbivore treatment (O=fenced, MWC=unfenced).
- Row: Row ID of sampling grid.
- Column: Column ID of sampling grid.
- Station: Sampling station ID (RowColumn).
- unqID: Unique sampling station ID (Block-Treatment-Sampling station)
- SpCode: Species code (see table below for details).
- PA: Species occurrence (presence-absence) in 1 m x 1 m quadrats.
- dT: Distance to termite mound (m).
- cum4mo: Cumulative 4-month antecedent rainfall (mm).
- cum4mo_t2: Cumulative 4-month antecedent rainfall of previous year (mm).
| SpCode | Species |
|---|---|
| AcaCre | Acalypha crenata |
| AerLan | Aerva lanata |
| AriKen | Aristida kenyensis |
| AspPlu | Aspilia pluriseta |
| BleInt | Blepharis integrifolia |
| BotIns | Bothriochloa insculpta |
| BraEru | Brachiaria eruciformis |
| BraLac | Brachiaria lachnantha |
| BraSem | Brachiaria semiundulata |
| ChlSub | Chlorophytum subpetiolatum |
| ComSpp | Commelina spp. |
| ConPed | Conyza pedunculata |
| CorcSp | Corchorus sp. |
| CrotSp | Crotalaria sp. |
| CypMar | Cyperus & Mariscus spp. |
| DigMil | Digitaria milanjiana |
| DigVel | Digitaria velutina |
| DinRet | Dinebra retroflexa |
| DysRad | Dyschoriste radicans |
| EraCyl | Eragrostis cylindriflora |
| EraTen | Eragrostis tenuifolia |
| EruAra | Erucastrum arabicum |
| EupIna | Euphorbia inaequilatera |
| EvoAls | Evolvulus alsinoides |
| FernSp | Fern sp. |
| GutCor | Gutenbergia cordifolia |
| HelGlu | Helichrysum glumaceum |
| HibFla | Hibiscus flavifolius |
| HibTri | Hibiscus trionum |
| IndBre | Indigofera brevicalyx |
| IndSch | Indigofera schimperi |
| IpoBif | Ipomoea biflora |
| JusDic | Justicia diclipteroides |
| JusSpp | Justicia spp. |
| KohAsp | Kohautia aspera |
| LeuGla | Leucas glabrata |
| LeuMar | Leucas martinicensis |
| LinNut | Lintonia nutans |
| LipJav | Lippia javanica |
| MelVel | Melhania velutina |
| MicKun | Microchloa kunthii |
| MisOro | Misopates orontium |
| MolNud | Mollugo nudicaulis |
| MonAng | Monsonia angustifolia |
| MonDeb | Monechma debile |
| OxySin | Oxygonum sinuatum |
| PanAtr | Panicum atrosanguineum |
| PelAlc | Pelargonium alchemilloides |
| PenMez | Pennisetum mezianum |
| PenStr | Pennisetum stramineum |
| PhyMad | Phyllanthus maderaspatensis |
| PleSpp | Plectranthus spp. |
| PolSph | Polygala sphenoptera |
| PorOle | Portulaca oleracea |
| PsiSch | Psilotrichum schimperi |
| RhiNdo | Rhinacanthus ndorensis |
| RhyHol | Rhynchosia holstii |
| SidCun | Sida cuneifolia |
| SolInc | Solanum incanum (campylacanthum) |
| SolInd | Solanum indicum |
| SpoFes | Sporobolus festivus |
| TheTri | Themeda triandra |
| TraBer | Tragus berteronianus |
Code/software
NA
Access information
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