The relationship between vegetation, plant functional diversity and environment on rock outcrops in the Western Ghats, India

Abstract

ABSTRACTBackground Rock outcrops support specialist plant communities that are often adapted to highly seasonal climates and heterogeneous soil cover. However, the relationship between environmental parameters and plant functional types remains unexplored in many regions of the world, including the Northern Western Ghats (NWG) in India.Aims In the present work, we aimed to characterise the vegetation of high and low elevation rock outcrops in the NWG, and investigate the relationship between plant functional types and environmental variables.Methods Vegetation surveys were conducted on 16 high elevation and 14 low elevation sites using a transect and quadrat method. Floristic data were used to calculate plant diversity and plant functional type abundance. The relationship between vegetation and climatic (temperature, precipitation) and soil (soil carbon and nitrogen) variables was explored using cluster and ordination analysis.Results Rock outcrop sites were grouped into two clusters based on elevation, distance from the sea and mean diurnal range. Plant functional type abundance was related to macro-environmental variables such as temperature, precipitation and soil nutrients such as carbon and nitrogen.Conclusions We inferred that the distribution and dominance of different plant functional types in the NWG are related to primarily by elevation (a proxy for temperature) and distance from the sea.Key policy highlightsVegetation of the NWG rock outcrops differ significantly based on elevation.Precipitation, temperature variables and distance from the sea are the key parameters associating with the difference in vegetation across elevation.Since vegetation on rock outcrops differs across elevations; it is essential to protect the outcrops at high as well as low elevations across the entire NWG.KEYWORDS: Indian rock outcropsvegetation-environment relationshipdiurnal rangeplant functional typeephemeral vegetationDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgmentsAK, BS, SV and MND are thankful to the Director, Agharkar Research Institute, Pune for facilities and encouragement. The authors thank Dr. Aparna Watve and Dr. Karthick Balasubramanian for critical discussions. AK would like to thank Dr. Girish Kulkarni and Dr. Sameer Padhye for solving some doubts related to R.Disclosure statementNo potential competing interest was reported by the authorData availability statementThe authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials.Supplementary materialSupplemental data for this article can be accessed online at https://doi.org/10.1080/17550874.2023.2255999Figure 1 Study area in the Northern Western Ghats of India showing rock outcrops sites sampled during present work. m a.s.l: meters above sea levelDisplay full sizeFigure 2 Sampling design showing transect-cum-quadrat method adopted for the present study. 1 m × 1 m quadrats (green) nested at the corners of 5 m × 5 m quadrats embedded within 20 m × 20 m quadrats were used for collecting vegetation data.Display full sizeFigure 3 Cluster dendrogram based on species occurrence using the Sørensen dissimilarity index for all sites (see Table S2). Sites marked in blue: Low-elevation outcrops (0-250m a.s.l); orange: High-elevation outcrops (600-1500m a.s.l)Display full sizeFigure 4 Non-metric multidimensional scaling (NMDS) based on plant functional type abundance from study sites (stress=0.09). Sites marked in blue: Low-elevation outcrops (0-250m a.s.l); orange: High-elevation outcrops (600-1500m a.s.l)Display full sizeFigure 5 Canonical Correspondence Analysis (CCA) of the environmental variables and plant functional types (See Table 2). Sites marked in blue: Low-elevation outcrops (0-250m a.s.l); orange: High-elevation outcrops (600-1500m a.s.l). Functional types are marked in green and environmental variables are marked in black. TempAnnRange: Temperature Annual Range AnnPreci: Annual Precipitation, MnDiurRange: Mean Diurnal Range, PreciWettestQuar: Precipitation of Wettest quarter, AnnMnTemp: Annual Mean Temperature, TempSeason: Temperature Seasonality, DistSea: Distance from the SeaDisplay full sizeAdditional informationFundingThis work was supported by Agharkar Research Institute in-house grant BD-01. Partial funding support received from Council for Scientific and Industrial Research, Government of India to SV and SARTHI, Maharashtra State to BS.Notes on contributorsAboli KulkarniAboliKulkarni((https://orcid.org/0000-0002-4495-977X) studied rock outcrops of the WesternGhats for her Ph.D., during which she studied vegetation diversity,distribution and its relationship to the environment.Rohan ShettiRohanShetti (https://orcid.org/0000-0002-2967-0193)is a post-doctoral research scientist in the field of plant ecology and climatechange, with most of his research focusing on understanding changes invegetation patterns with respect to contemporary climate warming in thesub-arctic, alpine as well as tropical regions.Bhushan K. ShigwanBhushanShigwan(https://orcid.org/0000-0001-8657-7502) is a plant taxonomist and ecologistinterested in forest ecology, diversity, fragmentation and distribution offorest trees in the Western Ghats.Smrithy VijayanSmrithyVijayan(https://orcid.org/0000-0003-4697-2641) is an ecology student with a particularinterest in cliff and outcrop vegetation and their ecological functioning.Mandar N. DatarMandar N. Datar (https://orcid.org/0000-0002-4437-7796) is a taxonomist and ecologistinterested in the diversity, distribution and endemism of flowering plants inthe Western Ghats.