Advertisement

Urban Ecosystems

, Volume 22, Issue 1, pp 161–172 | Cite as

Sacred sites, biodiversity and urbanization in an Indian megacity

  • Divya GopalEmail author
  • Moritz von der Lippe
  • Ingo Kowarik
Article

Abstract

In an era of rapid urban growth, conserving biodiverse urban green spaces is challenging, especially in developing countries. Culturally protected areas including sacred sites are known to contribute to biodiversity conservation in semi-urban and rural areas, but their role in dense urban settings is critically understudied. We, therefore, assessed biodiversity patterns of two types of Hindu places of worship (temples, kattes) and underlying environmental parameters in the Indian megacity of Bengaluru. We analyzed how variables of the urban matrix (age of development, housing density) and type of sacred sites related to biodiversity measures (species abundance, richness, beta diversity), differentiated for cultivated, spontaneous (i.e., wild growing), native and non-native plant species. Native species prevailed in cultivated (66%) and spontaneous (93%) species assemblages, and urbanization parameters significantly related to some biodiversity measures. Beta diversity was highest in sacred sites located in the newest quarters, while abundance of cultivated and non-native species increased with decreasing housing density. Higher richness in low density (i.e., wealthier) quarters demonstrates ‘luxury effect’ for sacred sites. Plots in temples showed higher diversity measures than in kattes, likely due to different management practices. While results demonstrate effects of urbanization on biodiversity measures for temples and kattes, these sites still function as habitats for native species in Bengaluru – and not as foci for invasive alien species as noticed for other urban green spaces. We conclude that urban sacred sites allow people to benefit from multiple ecosystems services and thus play an important role in the urban green infrastructure of quickly growing megacities.

Keywords

Unconventional greenspaces Native species Urban greenery Biodiversity conservation Religious site 

Introduction

With the rise in urban population globally, cities are increasingly becoming places where most people encounter nature (Soga and Gaston 2016). Contact with urban green spaces has been positively associated with health and wellbeing (Cohen-Cline et al. 2015; Shanahan et al. 2015). Urban habitats harbor a surprisingly high biodiversity (Shwartz et al. 2014). Yet, accelerating urban growth poses major threats to extant greenspaces, in particular in developing countries (Lin and Fuller 2013; Sudhira and Nagendra 2013). While there is substantial research regarding the impact of urbanization on biota in developed countries, the same for developing countries is not as well studied (Pauchard et al. 2006). While the urban sprawl in North American and European cities are better planned and characterized by peripheral suburbanization (Irwin and Bockstael 2007), the crux of urbanization is still centered around the urban core in developing countries (Lambin et al. 2001). The desire for rapid economic growth coupled with high population density and the general low environmental standards could adversely affect urban biodiversity in many developing countries including China (Jim and Chen 2006), Chile (Pauchard et al. 2006), India (Nagendra et al. 2013) and many others. With such different patterns of urbanization, conservation approaches need to be tailored to incorporate regional differences.

There is a wealth of evidence that a wide range of sacred sites, both natural and built structures, driven by religious and cultural beliefs, contribute significantly to biodiversity conservation around the world. Sacred natural sites (mostly found in rural areas) include sacred groves and forests of India (Bhagwat and Rutte 2006); shrines of central Italy (Frascaroli et al. 2016); culturally protected forests in China and Ethiopia (Gao et al. 2013; Woods et al. 2017); burial places in Morocco (Frosch and Deil 2011); and many more across South-East Asia, South America and Africa (Verschuuren et al. 2010). In the urban context, cities around the globe harbor sacred sites connected to mainstream religions including churchyards and cemeteries that consist of built structures interwoven with natural elements (e.g., cultivated and wild growing plants). In a South African town, urban sacred sites constitute 13.6% of public green spaces (De Lacy and Shackleton 2017b). While few studies demonstrate the role of such sites for biodiversity and cultural ecosystem services (Barrett and Barrett 2001; Kowarik et al. 2016; De Lacy and Shackleton 2017a, b; Yılmaz et al. 2017), Jackson and Ormsby (2017) recently state that the role of sacred sites in urban environments as potential repositories of biological diversity is not well documented, thus necessitating further systematic research. This certainly holds for India (Jaganmohan et al. 2018).

India has a long, rich tradition of conservation associated with religious and cultural beliefs. While sacred groves are conserved in many peri-urban areas and smaller towns, it is quite common to find massive, centuries-old sacred trees (e.g., Ficus religiosa, Ficus benghalensis, Tamarindus indica, etc.) being protected in densely congested urban neighborhoods across India (Nagendra 2016, Jaganmohan et al. 2018). Cultural taboos forbid cutting down sacred forests, groves and individual (sacred) tree and plant species (Bhagwat and Rutte 2006; Nagendra 2016). Many sacred plants have medicinal and culinary uses (Kurian 2004; Krishen 2006), which further contribute to their cultural relevance, also in cities (Gopal et al. 2018). While urban sacred sites could include institutions, natural sites (forests and groves), cemeteries and heritage sites, we studied places of worship connected to Hinduisms (built structures) – temples (built religious structures) and kattes (open-air tree shrines; see Table 1) and associated plant assemblages.
Table 1

Overview of environmental variables used to analyze biodiversity patterns in urban sacred sites of Bengaluru

Environmental variables

Scale

Data source

Age of urban development

Old: city boundary in 1941, representing the colonial era of the city.

Sudhira et al. 2007

 

Intermediate: area between 1941 and 1991 administrative boundaries, representing the post-independence to pre-globalization era.

 

New: area between 1991 to present administrative boundaries, representing the globalization - privatization era.

 

Housing density

High: slum areas with high more than 80 housing units / ha.

Eicher Goodearth Pvt. Ltd. 2002;

National Institute of Urban Affairs 2008

 

Medium: housing quarters (with ~ 20–40 housing units / ha.

 

Low: housing quarters with ~ 8–10 housing units / ha.

Sacred site type

Temples: Structured institutions with a formal governing body. High intensity gardening practices (planting, landscaping, mowing, irrigation). Site area: mean = 0.11 ± 0.20 ha; range = 0.01 ha – 1.89 ha.

Nagendra 2016

 

Kattes: Traditional systems of worship. Often community managed. Low intensity gardening practices. Site area: mean = 0.05 ± 0.11 ha; range = 0.01 ha – 2.56 ha.

 

Site area

Range: 0.01 ha – 2.56 ha

Direct assessment

With Bengaluru as a model city for a rapidly growing Indian megacity, we analyzed biodiversity patterns in sacred sites for different groups of plant species in response to urbanization. In particular, we assessed (i) total assemblages of cultivated plant species and (ii) total assemblages of spontaneous (i.e., wild growing) plant species. While the former directly descend from cultural interferences that may vary among different neighborhoods, the latter are less culturally shaped – as they include weedy species and escapees from cultivation – and could differently relate to urbanization. Moreover, we divided both groups as native and non-native species to test whether the latter relates positively to urbanization as in many other urban studies (Aronson et al. 2014, 2015).

Effects of urbanization on biodiversity are ideally studied using exact measures of urbanity on a fine spatial resolution that reflect the heterogeneity and complex spatio-temporal formation of the urban matrix (McDonnell and Hahs 2008; Ramalho and Hobbs 2012). Most of the commonly used proxies of urbanity are, however, not available on a sufficient spatial resolution for our study sites as for many Indian metropolitan areas. Hence, in the absence of such data, a reasonable approach that reflects the most important contrast in urban structure detectable from available sources had to be developed.

Due to unavailability of public data on socio-economics at the finer scale (neighborhood/district level) in Bengaluru, we focused on density of housing as an urbanization indicator of socio-economic status, reflecting lifestyle characteristics (Luck et al. 2009; Grove et al. 2014). As historical land use changes and legacies have been identified as highly relevant for urban biodiversity patterns (Ramalho and Hobbs 2012), we further included age of urban development as a temporal factor in differentiating the city. Apart from these, we also checked for differences within sacred ecosystems – temples and kattes – that form unique habitat types of different management and usage.

With this background, we aimed to study and identify drivers of vegetation diversity patterns in urban sacred sites. Specifically, whether (i) age of urban development and (ii) density of housing are related to (iii) abundance and species richness, and (iv) beta diversity in different groups of plant species (native, non-native, spontaneous and cultivated); and whether these relationships differ between (v) temples and kattes.

Methods

Study area

The study was carried out in the southern Indian megacity of Bengaluru, with an area of 741 km2. In the last two decades, Bengaluru has witnessed rapid and unplanned urbanization, with a population growth from 3.5 million in 1992 to around 10 million in 2011 (Census of India 2011). Loss of green spaces within the city, including parks, home gardens, avenue trees and open spaces, is high due to the immense pressure on land for infrastructure development. Despite laws protecting Bengaluru’s greenery (Karnataka Preservation of Trees Act 1976), large scale logging of trees continues (Sudhira and Nagendra 2013).

Sacred sites

Temples and kattes are two types of Hindu places of worship that we considered for our study (Table 1). Temples are places of worship with architectural structures/buildings dedicated to deities, often with a clear physical boundary. An organization or a government body often manages it, taking decisions about land-use/land management; including gardening, watering plants, choice of plants and weeding. While, kattes are community managed traditional open-air shrines with a combination of Ficus religiosa and other sacred trees in the center and serpent stones (stones depicting serpent deities) arranged around the tree(s) (Fig. 1). Structurally, the katte is often a raised platform without a clear physical fence or a wall around it and may include additional green elements such as potted plants, grass patches and cracks and crevices in the stones that may function as habitats for some spontaneous plants. Many sacred sites represent rural remnants within Indian cities (Nagendra 2016; Keswani 2017). Yet, we encountered new temples and kattes during the course of our study, in various parts of the city – although the age of many urban sacred sites (especially kattes) was often unknown. Even the older sacred sites may have gone through renovations at various time periods including greening and gardening efforts. Differences within sacred sites – temples and kattes – and the influence of the surrounding urban matrix on them, were therefore accounted for and included in the study design.
Fig. 1

a Katte – sacred trees on a raised platform in Bengaluru; b Temple facade with trees within the premises; c Lawn with ornamental species inside a temple

Study design

We used a stratified random sampling approach to account for major parameters that have been shown to often shape biodiversity patterns: Age of urban development (classified according to the three main development eras of Bengaluru city as old, intermediate and new; see Table 1) and housing density (categorized according to the number of housing units per hectare as high, medium and low). Age of urban development reflects contrast in urban structure and urbanization history for Bengaluru and is detectable from historical maps. Bengaluru had a very clear phasing in its urban development, resulting in three city zones of comparable age and development history (Sudhira et al. 2007). Housing density affects both urban structure and socio-economic status of citizens, indicating life style characteristics (Luck et al. 2009; Grove et al. 2014; Arshad and Routray 2018). Housing density gives an estimate of socio-economic status with higher household income indicating bigger houses, implying lesser number of housing units per hectare and vice versa (detailed definitions in Table 1).

The combination of the three factor levels of the two predictors (i.e., age – old, intermediate and new; and housing density – high, medium and low) resulted in 9 strata, in each of which 4 neighborhoods were selected randomly. As both types of sacred sites (temple and katte) are frequently encountered in the urban area of Bengaluru, a pair of temple and katte with a maximum distance of 0.5 km were selected randomly for each neighborhood (in every stratum) to ensure comparable environmental conditions in each pair. However, three localities did not have kattes, thus, resulting in 69 study sites across Bengaluru city (Fig. 2). Since total area of sacred sites varied, within each site, a 10 × 10 m2 plot was sampled to maintain uniform plot size across the study. In kattes, the plots were selected with the sacred tree (Ficus species or others) as the center, whereas temples were divided into grids and a 10 × 10 m2 plot was randomly selected for sampling. To determine graminoid counts, we randomly sampled a 1 × 1 m2 quadrat within each 100 m2 plot, counted the number of tillers (Kent 2011), determined species cover (percentage cover of each graminoid species in each plot) and calculated abundance data in each plot. In addition to the assignment of each plot to definite levels of both urbanization variables, the size of the total area of each sacred site (i.e., the property boundary including the built structures, henceforth referred to as site area) was measured by GIS analysis to account for the influence of area on biodiversity patterns.
Fig. 2

Location of 36 neighborhoods across Bengaluru, identified from stratified random sampling approach for all combinations of urbanity predictors - age of urban development and housing density. In each neighborhood, a pair of temple (n = 36) and katte (n = 33) with a maximum distance of 0.5 km from each other were selected randomly, resulting in 69 study sites. Satellite images: Examples of different housing densities from high to low. (Source: Google Earth 7.1.7.2606. (May 24, 2016). Bengaluru, India. High: 120 56′ 41.26” N, 770 35′ 34.89″ E. Medium: 130 00′ 19.14” N, 770 34′ 35.33″ E. Low: 130 00′ 36.33” N, 770 34′ 52.41″ E. Eye alt 1.09 km. Digital Globe 2016, Google 2016)

Data collection

Field studies were carried out between March and May 2014. Within each plot, all vascular plants (trees, saplings, shrubs, herbs and graminoids) were recorded. All plant species were identified and differentiated as native and non-native species to southern India based on Kehimkar (2000), Krishen (2006), Kurian (2004) and Neginhal (2006). Individual plants were counted and each individual was classified as either cultivated (planted) or spontaneous (wild growing: those that were not planted) (Pearse et al. 2018), based on information from gardeners or site managers in temples (n = 36) and two regular users (community members) in kattes (n = 66). This categorization was at the individual level as a given species could be cultivated at some sites and growing spontaneously at others. Information on spontaneous vs. cultivated species reflects on cultural practices, opportunities for wild flora in cities and invasion dynamics as cultivations often function as invasion foci (Pearse et al. 2018).

Statistical analyses

Statistical analysis was carried out separately for total species, spontaneous species, cultivated species, native species and non-native species. Species richness, abundance of individuals within the different species groups (henceforth referred to as abundance) and beta diversity were taken as response variables to analyze the effects of urbanization parameters and type of sacred site on biodiversity.

Beta diversity was calculated to estimate species variation among communities, using Bray-Curtis dissimilarity on count data. Each plot was compared to all other plots within the same factor level; i.e., to either all old, intermediate or new plots based on age of urban development. Similarly, beta diversity was calculated for factor levels based on housing density and site type.

The impact of urbanization on species richness and abundance was analyzed by negative binomial generalized linear models (GLM); with age, housing density and site type as predictors and area of the sacred sites as a control variable (since temples were generally larger in size than kattes). Negative binomial GLM was used to account for zero inflation in count data (Zuur et al. 2009). With site area as a control, we included only predictor variables and two-way interactions in the models. Models were simplified by stepwise backward selection based on AIC.

To test for the influence of environmental variables on difference in beta diversity between the factor levels, we carried out K-sample permutation test based on 9999 Monte Carlo permutations for each predictor group. This was followed up by a Nemenyi-Damico-Wolfe-Dunn (NDWD) post hoc test (Hollander et al. 2015). This test was also used for pairwise comparisons after GLMs when there were significant environmental variables with more than two factor levels.

Statistical tests were conducted using R, version 3.1.3 (R Development Core Team 2015). All diversity indices, dissimilarity measures, regression and ordination techniques were computed using the packages BiodiversityR (Kindt and Coe 2005), vegan (Oksanen et al. 2015) and MASS (Venables and Ripley 2002). The K-sample test was computed through the coin package, and the NDWD test with the multcomp package.

Results

Field sampling revealed that sacred sites in Bengaluru harbor 121 plant species, with differences in species assemblages related to characteristics of the surrounding urban areas and the types of sacred sites. Overall, there were 2913 individuals belonging to different plant groups. As seen in Table 2, both native species richness and abundance were higher than non-natives. Even within the cultivated species and spontaneous species pools, a similar pattern was noticed, i.e., cultivated native species and spontaneously growing native species had more species richness and individuals than cultivated non-natives and spontaneous non-natives. Trees (individuals ≥10 cm diameter at breast height) accounted for 171 individuals belonging to 38 species – 79% native (accounting to 93% of all individuals) with Ficus religiosa and Azadirachta indica as the most dominant species. In the tree layer, spontaneous individuals accounted for 13% of all counts (n = 171), while among the saplings, spontaneous individuals accounted for 56% of all sapling counts (n = 94, Ficus religiosa = 39%). Further, native species in the sapling layer accounted for 86% of all species (n = 21) and 96% of all counts (n = 94).
Table 2

Overall species numbers, proportional abundance (proportion of individual counts) and mean species richness found in sacred site plots in Bengaluru calculated for different plant groups, and results of Welch t-test for differences between means

 

Total species richness

%

Abundance (%)

Species richness Mean ± SD

t

Katte

Temple

 

Total species

121

100

100

4.3 ± 3.7

7.7 ± 6.0

−2.9 **

Native species

84

69

81

3.5 ± 3.0

6.1 ± 4.6

−2.7 **

Non-native species

37

31

19

0.8 ± 1.2

1.7 ± 2.7

−1.7 *

Cultivated species

104a

49

3.1 ± 3.0

5.7 ± 4.7

−2.9 **

 • Native

69

66

64

2.3 ± 2.4

4.2 ± 3.3

−2.6 **

 • Non-native

35

34

36

0.6 ± 1.2

1.5 ± 2.6

−1.8 *

Spontaneous species

30a

51

1.4 ± 1.6

2.1 ± 2.4

−1.2

 • Native

28

93

97

1.4 ± 1.5

2.0 ± 2.4

−1.3

 • Non-native

2

7

3

0.1 ± 0.3

0.1 ± 0.2

0.5

aAs some species were both cultivated and growing spontaneously, we looked at individual plant counts (abundance) for these groups. Significance levels of t-test: * <0.05; ** <0.01

Age of urban development

Age of urban development did not relate to abundance and species richness (Figs. 3 and 4) across all species pools. However, significant differences were found for beta diversity: Sacred sites located within new areas of the city had higher Bray-Curtis dissimilarity of species assemblages than study sites in the old and intermediate areas of the city, for the total and native species pools (Table 3). The NDWD post-hoc test further revealed that these differences were significant (p < 0.05). That is, species composition in new areas of Bengaluru was more heterogeneous (implying higher beta diversity) compared to other parts of the city.
Fig. 3

Effects of environmental variables (predictors) on abundance of individual plants for different species groups (total, spontaneous, cultivated, native and non-native plants) in Bengaluru’s sacred sites. Results (at p < 0.05) of negative binomial generalized linear models have been represented by box plots for the corresponding significant environmental variable

Fig. 4

Response of species richness for different plant groups (total, spontaneous, cultivated, native and non-native species) to environmental variables (predictors) in sacred sites of Bengaluru. Results (at p < 0.05) of negative binomial generalized linear models have been indicated by box plots for the corresponding significant environmental variable

Table 3

Effects of environmental variables on mean Bray-Curtis dissimilarity - Results of approximative K-sample permutation test for total, spontaneous, cultivated, native and non-native species pools

 

Mean Bray-Curtis dissimilarity

Chi-square

K-sample p value

NDWD Pairwise comparison significant differences at p < 0.05

Age

Old

Int.

New

   

Total

0.84

0.83

0.89

13.85

0.001

Old vs. New; Int. vs. New

Spontaneous

0.84

0.78

0.81

3.25

0.19

Cultivated

0.87

0.86

0.87

0.28

0.87

Native

0.81

0.81

0.88

16.98

< 0.001

Old vs. New; Int. vs. New

Non-native

0.92

0.93

0.95

0.89

0.65

Housing density

High

Med.

Low

   

Total

0.79

0.84

0.89

31.74

< 0.001

High vs. Low

Spontaneous

0.72

0.87

0.84

14.05

< 0.001

Cultivated

0.79

0.82

0.94

45.14

< 0.001

High vs. Low; Med. vs. Low

Native

0.76

0.83

0.87

37.49

< 0.001

High vs. Low

Non-native

0.94

0.95

0.93

0.14

0.94

Site type

Katte

Tmpl

 

z

  

Total

0.80

0.88

 

- 6.88

< 0.001

 

Spontaneous

0.79

0.80

 

- 0.72

0.47

 

Cultivated

0.81

0.90

 

- 5.89

< 0.001

 

Native

0.78

0.86

 

- 6.33

< 0.001

 

Non-native

0.97

0.94

 

1.10

0.28

 

NDWD, Nemenyi-Damico-Wolfe-Dunn test; Int., Intermediate age class; Med., Medium housing density; Tmpl, Temple

Housing density

Sacred sites located within low density housing areas had more individuals (higher abundance) of cultivated species than sites embedded in more dense quarters of the city (Fig. 3). However, the NDWD post-hoc test revealed that the differences between the factor levels were not significant (p = 0.75). Species richness of non-native species significantly related to housing density (Fig. 4) with low density housing quarters having more species than sites embedded in more dense quarters of the city. The value for low density housing was significantly higher than non-native species richness in medium density class (p = 0.03) as revealed by the NDWD post-hoc test.

Beta diversity was higher in sacred sites within low density quarters than sites in denser parts of the city for the total, cultivated and native species pools (Table 3).

Sacred site type

Sampled plots within temples had more species and individuals across total, native, non-native and cultivated species pools than same-sized plots in kattes (Figs. 3 and 4). Similarly, study plots in temples had significantly higher beta diversity (p < 0.001) than kattes (Table 3). That is, the species composition in kattes was more similar compared to temples.

Discussion

Urban sacred sites are not only of high cultural significance in many cities around the globe, but are gaining increasing attention for supporting biodiversity that can be directly accessed by urban residents (Kowarik et al. 2016; De Lacy and Shackleton 2017a; Jackson and Ormsby 2017). Yet, biodiversity functions of urban sacred sites are critically understudied, in particular in the Global South (Nagendra et al. 2013; Jackson and Ormsby 2017). Previous studies on larger (in area) sets of urban sacred sites have often focused on woody species and compared different types of sacred sites, but without disclosing urbanization effects (De Lacy and Shackleton 2017b; Jaganmohan et al. 2018). This is likely the first study on urban sacred sites that applied a stratified random sampling design to test how biodiversity measures calculated for different pools of species (i.e., cultivated species, spontaneous species, native species, nonnative species) and for two types of Hindu places of worship (temples, kattes), relate to urbanization parameters.

Native species were dominant in both types of sacred sites as seen in non-urban studies on sacred forests (Bhagwat et al. 2005; Woods et al. 2017). Another key insight was that some urbanization predictors were significantly related to biodiversity patterns, but with variations among differentiated species assemblages. Further, formally organized sites (temples) showed different biodiversity patterns than community managed sites (kattes).

With regard to tree species, the sampled sacred sites (despite smaller patch size) had a higher tree density (2.5 trees per 100 m2) and tree species richness (0.55 per 100 m2) compared to parks (density = 1.8 trees per 100 m2, richness = 0.1 trees/100 m2; Nagendra and Gopal 2011) and slums (density = 0.11 trees/100 m2, richness = 0.09 trees/100 m2; Gopal et al. 2015) of Bengaluru, similar to their larger counterparts within the city (Jaganmohan et al. 2018). These tiny sacred sites had higher tree density and diversity compared to sacred sites of Grahamstown, South Africa, as well (De Lacy and Shackleton 2017b), further highlighting the biodiversity potential of small green spaces within the urban fabric.

Age of urban development

As a surprising result, species richness and abundance were similar for all species pools in differently aged neighborhoods of Bengaluru (Figs. 3 and 4). This clearly contrasts with previous studies that have shown that age of urban development relates to plant diversity, with higher plant diversity in newer localities (Luck et al. 2009; Wang et al. 2012). In this context, sacred sites seem to be constant in time and space with no significant impact of age on species richness and abundance. While the exact age of individual sacred sites is unknown, there is evidence that many (but not all) sites represent rural remnants (Nagendra 2016; Keswani 2017); while others were established at later time periods. This heterogeneity in persistence of sacred sites might overlay effects due to the varying age of the surrounding urban environments. Further, changing historical preferences for plant species were related to diversity patterns in Bengaluru’s parks and slums (Nagendra and Gopal 2011; Gopal et al. 2015), but not in sacred sites – perhaps due to the long-established traditional structure and management regimes of these ecosystems.

In contrast, beta diversity significantly related to age of urban development in the total and native species pools with species assemblages in old and intermediate sites being more similar in composition than that in new sites (Fig. 3). This suggests that new communities are more heterogeneous and are homogenizing with age which could be an effect of higher variation in site conditions and opportunities for colonization in newly developed sacred sites compared to older ones.

Housing density

Richness of non-native species was higher in low density housing quarters than in the other two density classes (Fig. 4). Similarly, the abundance of cultivated species increased from high to low density housing quarters (Fig. 3). Both groups that are usually closely related to gardening, thus, show highest biodiversity measures in low density quarters, which have the highest socio-economic status in Bengaluru. Human population density (housing density used as a proxy for the same) has been identified as a predictor for non-native species richness in earlier studies (Sharma et al. 2010; Fuentes et al. 2015; Fischer et al. 2016). As low density quarters are clearly associated with a high socio-economic status in Bengaluru, our results provide first evidence for the “luxury effect” on urban sacred sites – the positive association of wealth with plant diversity (Hope et al. 2003). Consequently, high density housing quarters, mainly comprising of slums with lower household incomes, had lower plant diversity and abundance (data not shown). This further reflects on the role of socio-economics, including access to resources (land, finances, etc.) and lifestyle choices (gardening practices, etc.); in modulating plant diversity patterns.

Sacred site type

Our paired comparison with same-sized plots sampled both in kattes and temples allowed us to compare the species assemblages of these differently shaped and differently managed types of sacred sites. Site type significantly related to most diversity measures even after controlling for variations contributed by differences in total area of sites in our statistical models (Figs. 3 and 4). The higher diversity measures for temples compared to kattes, thus, can be related to different gardening practices since temples were more intensely managed than kattes (Table 1). Studies have shown an increase in non-native species with increasing management intensities including mowing, watering and pruning (Boughton et al. 2011; Tomasetto et al. 2013). Consequently, diversity of non-native species was higher for temples (high management intensity) than kattes (low management intensity). As an exception, the number (and abundance) of spontaneous species was similar in temples and kattes (Figs. 3, 4). The low mean species richness (for spontaneous individuals) of 1.4–2.0 per 100 m2 (Table 2) may result from weeding activities in temples.

Implications for management and conservation

Our study highlights sacred sites as habitats for native plant species that prevail in both cultivated and spontaneous species assemblages of temples and kattes (Table 2). Sacred sites show a higher proportion of native species (69%) as compared to other land-use types in Bengaluru (Gopal et al. 2015) and green spaces in other cities including Bandung (Abendroth et al. 2012), Santiago (Fischer et al. 2016), and Chennai (Muthulingam and Thangavel 2012). Surprisingly, the overwhelming majority (93%) of spontaneous species were native (Table 2). This illustrates sacred sites as habitats of some wild growing native species, but not as invasion foci despite considerably high numbers (36%) of cultivated non-native species.

Unlike many rural sacred sites (e.g., sacred groves and forests, Bhagwat et al. 2005), the species richness in our study was limited and rare species were largely missing. Yet, the value of common species is often underestimated (Gaston 2010). In the urban context where residents have limited access to nature (Soga and Gaston 2016), we emphasize opportunities of urban people to get in contact with native species within their neighborhoods. A companion study on the species composition of temples and kattes revealed the religious significance of many of the cultivated and spontaneous species and their usability for medicinal and other reasons (Gopal et al. 2018).

While there is higher acceptance of ‘wild’ elements in urban green spaces in other parts of the world (e.g., Weber et al. 2014; Rupprecht et al. 2015), manicured gardens with lawns and species of aesthetic value seem to be preferred in most land-use types in Bengaluru (Nagendra 2016), providing an example for conflicting views between ideals of neatness and a biodiversity-friendly management. This study illustrates the potential of urban sacred sites for spontaneous regeneration of plant species. Interestingly, tree saplings (largely Ficus religiosa) descending from natural regeneration (wild growing) were present at the sites accounting for 56% of all sapling counts. Yet, the mean species richness (for spontaneous individuals) of 1.4–2.0 per 100 m2 (Table 2) is rather low and may result from weeding.

Moreover, the generally smaller size and the openness (no fences) of kattes in contrast to temples increase the potential impacts of edge effects and herbivory (cattle and goats). Herbivory has also been identified as a threat to sacred sites in other regions, e.g., Ethiopia (Woods et al. 2017) and Morocco (Frosch and Deil 2011). Temples, therefore, seem to provide better conditions as sites for urban biodiversity. Perhaps, providing an array of differently managed sections within sacred sites may cater to a wide range of user groups. While some sections can be visitor friendly and regularly managed; others can be less-attended, allowing a higher level of natural ecosystem processing as proposed for old cemeteries in Europe (Kowarik et al. 2016).

Additionally, information about native and wild growing spontaneous species and the associated local fauna they support should be shared with visitors. Sharing such knowledge along with public involvement could raise awareness among visitors, augmenting acceptance of these ‘wild’ natural elements enhancing biodiversity (Shwartz et al. 2014).

Relevance of sacred sites within urban green infrastructure

Sacred sites are cultural heritage sites with an inherent conservation value, often protected by cultural taboos (Verschuuren et al. 2010). With cities in many developing countries losing green cover over infrastructure development, sacred sites can function as stable components of the urban green infrastructure. Cultural taboos associated with cutting down sacred plant species often seem to be more effective in saving trees and plant species, than formal systems of governance (Nagendra 2016).

In developing countries where economic growth takes precedence over urban green cover (Pauchard et al. 2006), sacred sites (both small and large) could contribute to ecological networks in highly fragmented urban areas and provide access to nature-experience for urban people – as described for other unconventional green spaces in western cities such as private gardens (Goddard et al. 2010), business sites (Serret et al. 2014), wastelands (Bonthoux et al. 2014) and cemeteries (Kowarik et al. 2016).

While urban centers in the Indian sub-continent have existing sacred spaces with immense community support, policy makers need to highlight the potential of these spaces for biodiversity and recognize them as crucial green spaces within the urban green infrastructure which would further enhance their protection and management. At the global scale, Bengaluru’s sacred spaces present excellent examples of unconventional green infrastructure maintained by urban communities.

Conclusions

Our study demonstrates the potential of sacred sites as habitats for native plants in a rapidly growing Indian megacity. While policies and practices need to be tailored in accordance with country-specific political and socio-economic components, existing (traditional) conservation practices need to be identified, integrated and empowered to pave new avenues towards enriching urban biodiversity. Community acceptance and co-operation in managing sacred spaces is often high due to their cultural relevance, as seen in Bengaluru, enhancing urban biodiversity conservation. Further research on faunal diversity in sacred spaces and influence of sacred spaces on microclimate could supplement the relevance of these unconventional green spaces.

Notes

Acknowledgements

Gesellschaft von Freunden der TU Berlin and Technische Universität Berlin funded this study. We thank H.S. Sudhira and Harini Nagendra for sharing map data of Bengaluru for different time periods; and HN and Leonie Fischer for their valuable inputs during the course of this research.

References

  1. Abendroth S, Kowarik I, Müller N, von der Lippe M (2012) The green colonial heritage: Woody plants in parks of Bandung, Indonesia. Landsc Urban Plan 106:12–22CrossRefGoogle Scholar
  2. Aronson MF, La Sorte FA, Nilon CH, Katti M, Goddard MA, Lepczyk CA, Warren PS, Williams NS, Cilliers S, Clarkson B, Dobbs C (2014) A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers. Proc R Soc B 281(1780):20133330CrossRefGoogle Scholar
  3. Aronson MF, Handel SN, La Puma IP, Clemants SE (2015) Urbanization promotes non-native woody species and diverse plant assemblages in the New York metropolitan region. Urban Ecosyst 18(1):31–45CrossRefGoogle Scholar
  4. Arshad HSH, Routray JK (2018) From socioeconomic disparity to environmental injustice: the relationship between housing unit density and community green space in a medium city in Pakistan. Local Environ 23(5):536–548CrossRefGoogle Scholar
  5. Barrett GW, Barrett TL (2001) Cemeteries as repositories of natural and cultural diversity. Conserv Biol 15:1820–1824. https://doi.org/10.1046/j.1523-1739.2001.00410.xGoogle Scholar
  6. Bhagwat S, Rutte C (2006) Sacred groves: potential for biodiversity management. Front Ecol Environ 4:519–524. https://doi.org/10.1890/1540-9295(2006)4[519:SGPFBM]2.0.CO;2Google Scholar
  7. Bhagwat SA, Kushalappa CG, Williams PH, Brown ND (2005) The role of informal protected areas in maintaining biodiversity in the Western Ghats of India. Ecol Soc 19:1853–1862.  https://doi.org/10.1111/j.1523-1739.2005.00248.x CrossRefGoogle Scholar
  8. Bonthoux S, Brun M, Di Pietro F et al (2014) How can wastelands promote biodiversity in cities? A review. Landsc Urban Plan 132:79–88.  https://doi.org/10.1016/j.landurbplan.2014.08.010 CrossRefGoogle Scholar
  9. Boughton EH, Quintana-Ascencio PF, Nickerson D, Bohlen PJ (2011) Management intensity affects the relationship between non-native and native species in subtropical wetlands. Appl Veg Sci 14:210–220.  https://doi.org/10.1111/j.1654-109X.2010.01116.x CrossRefGoogle Scholar
  10. Census of India (2011) Provisional population totals paper 1 of 2011: Karnataka. Directorate of Census Operations, Government of India, New DelhiGoogle Scholar
  11. Cohen-Cline H, Turkheimer E, Duncan GE (2015) Access to green space, physical activity and mental health: a twin study. J Epidemiol Community Health 69(6):523–529CrossRefGoogle Scholar
  12. De Lacy P, Shackleton CM (2017a) Aesthetic and spiritual ecosystem services provided by urban sacred sites. Sustainability 9:1628CrossRefGoogle Scholar
  13. De Lacy P, Shackleton CM (2017b) Woody plant species richness, composition and structure in urban sacred sites, Grahamstown, South Africa. Urban Ecosyst 20(5):1169–1179.  https://doi.org/10.1007/s11252-017-0669-y CrossRefGoogle Scholar
  14. Eicher Goodearth Pvt. Ltd (2002) Bangalore city map: a map book covering 480 sq. kms of Bangalore, including Yelahanka, Whitefield and Putenhalli. Eicher Goodearth Pvt. Ltd, New DelhiGoogle Scholar
  15. Fischer LK, Rodorff V, von der Lippe M, Kowarik I (2016) Drivers of biodiversity patterns in parks of a growing south American megacity. Urban Ecosyst 19:1–19.  https://doi.org/10.1007/s11252-016-0537-1 CrossRefGoogle Scholar
  16. Frascaroli F, Bhagwat S, Guarino R, Chiarucci A, Schmid B (2016) Shrines in Central Italy conserve plant diversity and large trees. Ambio 45:468–479.  https://doi.org/10.1007/s13280-015-0738-5 CrossRefPubMedGoogle Scholar
  17. Frosch B, Deil U (2011) Forest vegetation on sacred sites of the Tangier Peninsula (NW Morocco) - discussed in a SW-Mediterranean context. Phytocoenologia 41:153–181.  https://doi.org/10.1127/0340-269X/2011/0041-0503 CrossRefGoogle Scholar
  18. Fuentes N, Saldana A, Kühn I, Klotz S (2015) Climatic and socio-economic factors determine the level of invasion by alien plants in Chile. Plant Ecol Divers 8:371–377.  https://doi.org/10.1080/17550874.2014.984003 CrossRefGoogle Scholar
  19. Gao H, Ouyang Z, Chen S, van Koppen CSA (2013) Role of culturally protected forests in biodiversity conservation in Southeast China. Biodivers Conserv 22:531–544.  https://doi.org/10.1007/s10531-012-0427-7 CrossRefGoogle Scholar
  20. Gaston KJ (2010) Valuing common species. Science 327(5962):154–155CrossRefGoogle Scholar
  21. Goddard MA, Dougill AJ, Benton TG (2010) Scaling up from gardens: biodiversity conservation in urban environments. Trends Ecol Evol 25:90–98.  https://doi.org/10.1016/j.tree.2009.07.016 CrossRefPubMedGoogle Scholar
  22. Gopal D, Nagendra H, Manthey M (2015) Vegetation in Bangalore’s slums: composition, species distribution, density, diversity, and history. Environ Manag 55:1390–1401.  https://doi.org/10.1007/s00267-015-0467-3 CrossRefGoogle Scholar
  23. Gopal D, von der Lippe M, Kowarik I (2018) Sacred sites as habitats of culturally important plant species in an Indian megacity. Urban For Urban Green 32:113–122.  https://doi.org/10.1016/j.ufug.2018.04.003 CrossRefGoogle Scholar
  24. Grove JM, Locke DH, O’Neil-Dunne JP (2014) An ecology of prestige in New York City: examining the relationships among population density, socio-economic status, group identity, and residential canopy cover. Environ Manag 54(3):402–419CrossRefGoogle Scholar
  25. Hollander M, Wolfe DA, Chicken E (2015) Nonparametric statistical methods. John Wiley & Sons, Inc., Hoboken, NJ, USACrossRefGoogle Scholar
  26. Hope D, Gries C, Zhu W, Fagan WF, Redman CL, Grimm NB, Nelson AL, Martin C, Kinzig A (2003) Socioeconomics drive urban plant diversity. Proc Natl Acad Sci U S A 100:8788–8792CrossRefGoogle Scholar
  27. Irwin EG, Bockstael NE (2007) The evolution of urban sprawl: evidence of spatial heterogeneity and increasing land fragmentation. Proc Natl Acad Sci U S A 104:20672–20677.  https://doi.org/10.1073/pnas.0705527105 CrossRefPubMedPubMedCentralGoogle Scholar
  28. Jackson W, Ormsby A (2017) Urban sacred natural sites–a call for research. Urban Ecosyst 20(3):675–681CrossRefGoogle Scholar
  29. Jaganmohan M, Vailshery LS, Mundoli S, Nagendra H (2018) Biodiversity in sacred urban spaces of Bengaluru, India. Urban For Urban Green 32:64–70CrossRefGoogle Scholar
  30. Jim CY, Chen WY (2006) Perception and attitude of residents toward urban green spaces in Guangzhou (China). Environ Manag 38(3):338–349CrossRefGoogle Scholar
  31. Kehimkar I (2000) Common Indian wild flowers. Oxford University Press, Mumbai, IndiaGoogle Scholar
  32. Kent M (2011) Vegetation description and data analysis: a practical approach, 2nd edn. John Wiley & Sons, Sussex, UKGoogle Scholar
  33. Keswani K (2017) The practice of tree worship and the territorial production of urban space in the Indian neighbourhood. J Urban Des 22(3):370–387CrossRefGoogle Scholar
  34. Kindt R, Coe R (2005) Tree diversity analysis. A manual and software for common statistical methods for ecological and biodiversity studies. World Agroforestry Centre (ICRAF), NairobiGoogle Scholar
  35. Kowarik I, Buchholz S, von der Lippe M, Seitz B (2016) Biodiversity functions of urban cemeteries: evidence from one of the largest Jewish cemeteries in Europe. Urban For Urban Green 19:68–78.  https://doi.org/10.1016/j.ufug.2016.06.023 CrossRefGoogle Scholar
  36. Krishen P (2006) Trees of Delhi. Penguin Books, New Delhi, IndiaGoogle Scholar
  37. Kurian DJ (2004) Plants that heal. Oriental Watchman Publishing House, Pune, IndiaGoogle Scholar
  38. Lambin EF, Turner BL, Geist HJ, Agbola SB, Angelsen A, Bruce JW, Coomes OT, Dirzo R, Fischer G, Folke C, George PS, Homewood K, Imbernon J, Leemans R, Li X, Moran EF, Mortimore M, Ramakrishnan PS, Richards JF, Skånes H, Steffen W, Stone GD, Svedin U, Veldkamp TA, Vogel C, Xu J (2001) The causes of land-use and land-cover change: moving beyond the myths. Glob Environ Chang 11:261–269.  https://doi.org/10.1016/S0959-3780(01)00007-3 CrossRefGoogle Scholar
  39. Lin BB, Fuller RA (2013) Sharing or sparing? How should we grow the world’s cities? J Appl Ecol 50:1161–1168.  https://doi.org/10.1111/1365-2664.12118 CrossRefGoogle Scholar
  40. Luck GW, Smallbone LT, O’Brien R (2009) Socio-economics and vegetation change in urban ecosystems: patterns in space and time. Ecosystems 12:604–620.  https://doi.org/10.1007/s10021-009-9244-6 CrossRefGoogle Scholar
  41. McDonnell MJ, Hahs AK (2008) The use of gradient analysis studies in advancing our understanding of the ecology of urbanizing landscapes: current status and future directions. Landsc Ecol 23:1143–1155.  https://doi.org/10.1007/s10980-008-9253-4 CrossRefGoogle Scholar
  42. Muthulingam U, Thangavel S (2012) Density, diversity and richness of woody plants in urban green spaces: a case study in Chennai metropolitan city. Urban For Urban Green 11:450–459.  https://doi.org/10.1016/j.ufug.2012.08.003 CrossRefGoogle Scholar
  43. Nagendra H (2016) Nature in the city: Bengaluru in the past, present and future. Oxford University Press, New DelhiCrossRefGoogle Scholar
  44. Nagendra H, Gopal D (2011) Tree diversity, distribution, history and change in urban parks: studies in Bangalore, India. Urban Ecosyst 14:211–223.  https://doi.org/10.1007/s11252-010-0148-1 CrossRefGoogle Scholar
  45. Nagendra H, Sudhira HS, Katti M, Schewenius M (2013) Sub-regional assessment of India: effects of urbanization on land use, biodiversity and ecosystem services. In: Elmqvist T, Fragkias M, Goodness J et al (eds) Urbanization, biodiversity and ecosystem services: challenges and opportunities: a global assessment. Springer Netherlands, Dordrecht, pp 65–74.  https://doi.org/10.1007/978-94-007-7088-1_6 CrossRefGoogle Scholar
  46. National Institute of Urban Affairs (2008) Urban poverty reduction strategy for Bangalore. New DelhiGoogle Scholar
  47. Neginhal S (2006) Golden trees, greenspaces, and urban forestry. Self published, Bangalore, IndiaGoogle Scholar
  48. Oksanen J, Kindt R, Legendre P, et al (2015) Vegan: community ecology package. R package version 2.2-1. R Development Core Team, Vienna. http://CRAN.R-project.org/package=vegan (accessed 17 March 2017)
  49. Pauchard A, Aguayo M, Pena E, Urrutia R (2006) Multiple effects of urbanization on the biodiversity of developing countries: the case of a fast-growing metropolitan area (Concepcion, Chile). Biol Conserv 127:272–281CrossRefGoogle Scholar
  50. Pearse WD, Cavender-Bares J, Hobbie SE, Avolio ML, Bettez N, Roy Chowdhury R, Darling LE, Groffman PM, Grove JM, Hall SJ, Heffernan JB, Learned J, Neill C, Nelson KC, Pataki DE, Ruddell BL, Steele MK, Trammell TLE (2018) Homogenization of plant diversity, composition, and structure in north American urban yards. Ecosphere 9(2).  https://doi.org/10.1002/ecs2.2105
  51. R Development Core Team (2015) R: A language and environment for statistical computing, reference index version 3.1.3. R Foundation for Statistical Computing, Vienna, Austria. URL: http://www.R-project.org/. (accessed 17 March 2017)
  52. Ramalho CE, Hobbs RJ (2012) Time for a change: dynamic urban ecology. Trends Ecol Evol 27:179–188.  https://doi.org/10.1016/j.tree.2011.10.008 CrossRefPubMedGoogle Scholar
  53. Rupprecht CDD, Byrne JA, Ueda H, Lo AY (2015) ‘It’s real, not fake like a park’: residents’ perception and use of informal urban green-space in Brisbane, Australia and Sapporo, Japan. Landsc Urban Plan 143:205–218.  https://doi.org/10.1016/j.landurbplan.2015.07.003 CrossRefGoogle Scholar
  54. Serret H, Raymond R, Foltête JC, Clergeau P, Simon L, Machon N (2014) Potential contributions of green spaces at business sites to the ecological network in an urban agglomeration: the case of the Ile-de-France region, France. Landsc Urban Plan 131:27–35.  https://doi.org/10.1016/j.landurbplan.2014.07.003 CrossRefGoogle Scholar
  55. Shanahan DF, Lin BB, Bush R, Gaston KJ, Dean JH, Barber E, Fuller RA (2015) Toward improved public health outcomes from urban nature. Am J Public Health 105(3):470–477CrossRefGoogle Scholar
  56. Sharma GP, Esler KJ, Blignaut JN (2010) Determining the relationship between invasive alien species density and a country’s socio-economic status. S Afr J Sci 106:1–6.  https://doi.org/10.4102/sajs.v106i3/4.113 CrossRefGoogle Scholar
  57. Shwartz A, Turbé A, Simon L, Julliard R (2014) Enhancing urban biodiversity and its influence on city-dwellers : an experiment. Biol Conserv 171:82–90.  https://doi.org/10.1016/j.biocon.2014.01.009 CrossRefGoogle Scholar
  58. Soga M, Gaston KJ (2016) Extinction of experience: the loss of human-nature interactions. Front Ecol Environ 14:94–101.  https://doi.org/10.1002/fee.1225 CrossRefGoogle Scholar
  59. Sudhira HS, Nagendra H (2013) Local assessment of Bangalore: graying and greening in Bangalore – impacts of urbanization on ecosystems, ecosystem services and biodiversity. In: Elmqvist T, Fragkias M, Goodness J et al (eds) Urbanization, biodiversity and ecosystem services: challenges and opportunities: a global assessment. Springer Netherlands, Dordrecht, pp 75–91Google Scholar
  60. Sudhira HS, Ramachandra TV, Subrahmanya MHB (2007) Bangalore. Cities 24:379–390.  https://doi.org/10.1016/j.cities.2007.04.003 CrossRefGoogle Scholar
  61. Tomasetto F, Duncan RP, Hulme PE (2013) Environmental gradients shift the direction of the relationship between native and alien plant species richness. Divers Distrib 19:49–59.  https://doi.org/10.1111/j.1472-4642.2012.00939.x CrossRefGoogle Scholar
  62. Venables WN, Ripley BD (2002) Modern applied statistics with S, 4th edn. Springer, New York. isbn:0-387-95457-0Google Scholar
  63. Verschuuren B, Wild R, McNeely J, Oviedo G (2010) Sacred natural sites: conserving nature and culture. Earthscan, LondonGoogle Scholar
  64. Wang HF, MacGregor-Fors I, Lopez-Pujol J (2012) Warm-temperate, immense, and sprawling: plant diversity drivers in urban Beijing, China. Plant Ecol 213:967–992.  https://doi.org/10.1007/s11258-012-0058-9 CrossRefGoogle Scholar
  65. Weber F, Kowarik I, Säumel I (2014) A walk on the wild side: perceptions of roadside vegetation beyond trees. Urban For Urban Green 13:205–212.  https://doi.org/10.1016/j.ufug.2013.10.010 CrossRefGoogle Scholar
  66. Woods CL, Cardelus CL, Scull P et al (2017) Stone walls and sacred forest conservation in Ethiopia. Biodivers Conserv 26(1):209–221.  https://doi.org/10.1007/s10531-016-1239-y CrossRefGoogle Scholar
  67. Yılmaz H, Kuşak B, Akkemik Ü (2017) The role of Aşiyan cemetery (İstanbul) as a green urban space from an ecological perspective and its importance in urban plant diversity. Urban For Urban Green 33:92–98.  https://doi.org/10.1016/j.ufug.2017.10.011 CrossRefGoogle Scholar
  68. Zuur AF, Ieno EN, Walker NJ, Saveliev AA, Smith GM (2009) Mixed effects models and extensions in ecology with R. Springer, New YorkCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of EcologyTechnische Universität BerlinBerlinGermany
  2. 2.Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB)BerlinGermany

Personalised recommendations