1. Elevational range size patterns reflect ecological and evolutionary processes, but they are also affected by geometric constraints. The confounding effect of these constraints led to an ongoing controversy about the elevational Rapoport’s rule, which postulates a positive association between the range size and elevation, and about the plausibility of the climate variability hypotheses as its causal explanation.

2. Here we used an advanced null modelling approach to disentangle the interacting effects of geometric constraints and species richness gradients on the elevational range size of vascular plants. We collected extensive field data on elevational distribution for 728 vascular plant species occurring in the Ladakh region, Western Himalaya. We supplied these regional data with sub-continental elevational ranges extracted from the literature. Moreover, we used in-situ measured temperatures to quantify temperature variability along an elevational gradient to test the climate variability hypothesis.

3. Observed range size patterns were sensitive to methods used to quantify the average range size. Range truncation disproportionately affected regional ranges of low-elevation species and resulted in spurious support of elevational Rapoport’s rule. However, when the confounding effects of domain boundaries and richness gradient were controlled, our null models revealed only slight deviations from the random expectations of elevational range size patterns, contrasting with the prediction of the Rapoport’s rule. In line with these findings, seasonal and diurnal temperature variability did not change with elevation.

4. Synthesis: Geometric constraints combined with underlying species richness gradient create range size patterns seemingly supporting Rapoport´s elevational rule. However, null models accounting for these effects indicate that the range-size of vascular plants in the Himalayas does not increase with elevation. Given the universality of the geometric constraints and species richness gradient, our results suggest that these confounding factors must be controlled when testing Rapoport’s rule. The null model approach described here provides an efficient tool to do that.

Elevational species range data from Ladakh (regional ranges) are based on our systematic floristic exploration of Ladakh conducted between 1997 and 2015, comprising 102,999 species occurrences recorded from 4,062 distinct localities.

Sub-continental elevational range size refers to species ranges in the whole High Asia and was compiled from secondary sources: the Flora of Pakistan (https://www.tropicos.org/Project/Pakistan), the Flora of China (www.eFloras.org), the Flora of Nanga Parbat (Dickoré & Nüsser, 2000), Dentant (2018), The Himalayan Uplands Plant database (Dickoré, 2011), and the Global Biodiversity Information Facility (GBIF, https://www.gbif.org). Elevational records from the GBIF were rounded to the nearest hundred. Unreliable outliers based on historical records (i.e. published elevation more than 1000 m apart from other records) were omitted and the next reliable occurrence extreme was used instead.

This dataset contains R code a two files containing data supporting publication:
Macek M., Dvorský M., Kopecký M., Wild J. & Doležal J. (2021) Elevational range size patterns of vascular plants in Himalaya contradict Rapoport’s rule. Journal of Ecology.

R code:
RCode_Macek_2021_ElevationalRangeSizes_JEcol.R

Species data table: "species_data.txt"
- tab-delimited table, contains information on elevational range for 1054 vascular plant species occuring in Ladakh, India.

Dataset column description:
Species - species name (text)
Family - phylogenetig grouping to family (text)
FunctionalType - functional type (text)
n - No. of records in Ladakh (numeric)
MinRangeRegional - Min. recorded elevation in Ladakh (m a.s.l.), primary data - florictic surveys by L.Klimeš and J.Dolezal (numeric)
MaxRangeRegional - Max. recorded elevation in Ladakh (m a.s.l.), primary data - florictic surveys by L.Klimeš and J.Dolezal (numeric)
MinLiteratureCont - Min. recorded elevation at a sub-continental scale (Ladakh & adjacent regions) (m a.s.l.), compiled from primary data and literature search (numeric)
MaxLiteratureCont - Max. recorded elevation at a sub-continental scale (Ladakh & adjacent regions) (m a.s.l.), compiled from primary data and literature search (numeric)

Climatic data table: "climatic_data.txt"
- tab-delimited table, contains information on climatic variability in Ladakh, India from TOMST TMS3 temperature sensors (Wild et al. 2019). Temperature was measured 15cm above ground. First 18 lines contain definitions of columns.

Dataset column description:
SiteID  locality ID
Elev - site elevation (m a.s.l.)                                                    
Lat - latitude; decimal degrees, rounded to 2 decimal places                                                    
Lon - longitude; decimal degrees, rounded to 2 decimal places                                                    
Startdate - Measurement start date                                                    
Enddate - Measurement end date                                                    
Tmean - Average temperature from all measurements (15min interval, in °C)                                                    
Tmin - Average minimum daily temperature of the coldest month (°C)                                                    
Tmax - Average daily maximum temperature of the warmest month (°C)                                                    
SeasonalRange - Tmax - Tmin (°C)                                                    
AvgTmin - Average daily min temperature  (°C)                                                    
AvgTmax - Average daily max temperature (°C)                                                    
Diurnal Range - average daily diurnal range (AvgTmax - AvgTmin)  (°C)                                                    
AbsTmin - Absolute minimum temperature (°C)                                                    
AbsTmax - Absolute maximum temperature (°C)                                                    

reference:
Wild, J., Kopecký, M., Macek, M., Šanda, M., Jankovec, J., & Haase, T. (2019). Climate at ecologically relevant scales: A new temperature and soil moisture logger for long-term microclimate measurement. Agricultural and Forest Meteorology, 268, 40–47. doi: 10.1016/j.agrformet.2018.12.018