permaculture

[Steve Diver <steved@ncat.org>]

A Landscape Approach to Biodiversity Conservation of Sacred
Groves in the Western Ghats of India

Conservation Biology
Volume 19 Issue 6 (December 2005)
Pages 1853 - 1862

Shonil A. Bhagwat, Cheppudira G. Kushalappa, Paul H. Williams,
and Nick D. Brown

http://dx.doi.org/10.1111/j.1523-1739.2005.00248.x


Abstract:

Although sacred groves are important for conservation in
India, the landscape that surrounds them has a vital
influence on biodiversity within them. Research has focused
on tree diversity inside these forest patches. In a coffee-growing
region [in Kodagu district of Karnataka state] of the Western
Ghats, however, landscape outside sacred groves is also
tree covered because planters have retained native trees
to provide shade for coffee plants.

We examined the diversity of trees, birds, and macrofungi
at 58 sites—10 forest-reserve sites, 25 sacred groves, and
23 coffee plantations— in Kodagu district. We measured
landscape composition and configuration around each site
with a geographic information system. To identify factors
associated with diversity we constructed multivariate models
by using a decision-tree technique.

The conventional measures of landscape fragmentation such
as patch size did not influence species richness. Distance
of sacred groves from the forest reserve had a weak influence.
The measures of landscape structure (e.g., tree cover in
the surroundings) and stand structure (e.g., variability in
canopy height) contributed to the variation in species richness
explained by multivariate models. We suggest that biodiversity
present within sacred groves has been influenced by native
tree cover in the surrounding landscape. To conserve this
biodiversity the integrity of the tree-covered landscape matrix
will need to be conserved.



Selected excerpts:


Introduction:

Sacred groves are protected in the belief that "to keep them
in a relatively undisturbed state is expressive of an important
relationship of human beings with nature" (Hughes &
Chandran 1998). In India this community-based tradition
has received considerable attention from a sociological as
well as a biological perspective (e.g., Ramakrishnan 1996;
Chandrashekara & Sankar 1998; Ramanujam & Kadamban
2001). Although they may cover a miniscule proportion of the
total area of the country, the number of such groves is
estimated to be between 100,000 and 150,000 (Malhotra 1998).
With about 600,000 villages in the Indian countryside (Census
of India 2001), sacred groves form an integral part of the
rural landscape.

This informal network of nature reserves plays an important
role in maintaining tree diversity. Results of a comparison
between sacred groves and formal reserves have shown that
sacred groves shelter a high diversity of medicinal plants and
have more vigorous regeneration of trees than do formal reserves
(Boraiah et al. 2003). Sacred groves also have higher diversity
of tree species diversity than do formal reserves (Bhandary
& Chandrashekar 2003; Jamir & Pandey 2003; Ramanujam
& Cyril 2003). With ever-increasing pressure on the Indian
countryside, sacred groves have become patches of
seminatural forest in an otherwise cultivated landscape.
Biological research has been confined to studies of
biodiversity within the scared-grove patches themselves.
The influence of the human-modified landscape surrounding
sacred groves on species diversity, however, is rarely studied.

We used a landscape approach to study sacred groves in
the Kodagu region of India. This is a coffee-growing region
where a high percentage of native tree cover is still intact
to provide shade for coffee plants. The presence of native
trees in the landscape matrix surrounding sacred groves
is likely to influence biodiversity within the forest patches.
Although our emphasis was on patterns of tree diversity,
we also compared diversity patterns of birds and
macrofungi. We ask, What influence do the composition
and configuration of the surrounding landscape have
on biodiversity within sacred groves?



Species Diversity

We recorded 215 tree species, 86 bird species, and 163
macrofungus species. Forty-five percent of all tree species,
40% of bird species, and 39% of macrofungus species were
found in all three land-use types—forest reserve, sacred
groves, and coffee plantations. Coffee plantations shared
26% of tree species, 35% of bird species, and 21% of
macrofungus species with the other two land-use types.


Discussion

Importance of Landscape Surrounding Sacred Groves

Sacred groves in Kodagu are patches of forest in a
landscape hat probably once had continuous tree cover.
The biogeographic processes related to species loss
from forest remnants (e.g., Turner 1996; Turner et al.
1996) have had an obvious effect on sacred groves
(S.A.B., unpublished data), but it appears that the
tree-covered nature of the surrounding landscape may
have reduced the intensity of the species loss and
maintained the similarity in species composition of
sacred groves and the forest reserve despite the
distance. We also found no significant differences in
the distribution of biodiversity in the forest reserve,
sacred groves, and coffee plantations, and no
significant decline in biodiversity of sacred groves
with decrease in patch size or with increase in
distance from the forest reserve.

Although sacred groves alone cannot represent all
biodiversity in the region, the loss of these groves
would result in the decline of landscape-scale
heterogeneity that these patches provide (Quinn
& Harrison 1988; Lapin & Barnes 1995). The
landscape outside forest reserve in Kodagu shelters
species that are not protected by the formal reserve
network. Threatened tree species such as Actinodaphne
lawsonii Gamble, Hopea ponga (Dennst.) Mabberley,
Madhuca neriifolia (Thw.) H.J. Lam, and Syzygium
zeylanicum (L.) DC. (e.g., FRLHT 1999; IUCN 2003)
were found exclusively in sacred groves. We found
other threatened species such as Michelia champaca L.
and endemic species such as Pittosporum dasycaulon
Miq. in sacred groves and coffee plantations but not in
the forest reserve. Between 17 and 90% of stems of
the threatened and endemic species were between
1 and 10 cm dbh, suggesting that these species are
able to regenerate in sacred groves. Because these
species cannot regenerate in coffee plantations where
all small individuals are regularly cut back, their future
survival will require propagation as shade trees to
maintain tree cover in the landscape.

Bird species such as Loten's Sunbird (Nectarinia lotenia
L.), an endemic species, and the Nilgiri Flycatcher
(Eumyias albicaudata Jerdon), an endemic and threatened
species, were restricted to sacred groves and coffee
plantations. Forty-nine out of 163 species of macrofungi
were unique to sacred groves. Their survival will require
conservation of land outside the forest reserve. The
complexity of land management types in Kodagu
(e.g., Elouard 2000) means future management will
have to consider the existing land-management practices.
However, the principle of maintaining native tree cover
holds if the goal is to achieve conservation of
biodiversity in the Kodagu landscape.



Biodiversity-Friendly Coffee Production

Native tree cover remains intact in many parts of Kodagu
because of the production of shade-grown coffee. Our
results suggest that the tree-covered nature of these
coffee plantations may have made an important
contribution to maintaining biodiversity within sacred
groves. The improved irrigation, however, has allowed
planters to fell native trees (which retain moisture in
the plantations due to their dense foliage) and
replace them with exotics (which often have sparse
canopies) (e.g., Perfecto et al. 1996; Moguel &
Toledo 1999). Introduced trees such as Grevillea
robusta Cunn. have straight boles, which can also
be used to train black pepper ( Piper nigrum L.)
vines, an important source of additional income
for coffee planters. Conservationists in Latin America
are promoting cultivation of shade coffee because
of the importance of native shade trees for biodiversity
conservation in coffee production areas (but see Philpott
& Dietsch 2003; Rappole et al. 2003a, b). In our
opinion, a similar promotion would be beneficial
in Kodagu.

In Latin America when local landowners reach some
basic level of economic security they are likely to
become interested in ecological sustainability,
long-term environmental planning, and biodiversity
conservation (Southgate & Clark 1993). Gobbi
(2000) suggests that in El Salvador, biodiversity
conservation in shade coffee plantations can be
viable but incentives to small farmers from the
government are necessary. These could be in form
of tax reductions, loan facilities, subsidies, and
a secure market for biodiversity-friendly coffee.
For such cultivation practices to be successful
in Kodagu, it would be necessary for the government
to support small-scale planters so they will in turn
support biodiversity conservation. Certification of
coffee plantations by setting standards for
sustainable management can encourage
planters to grow coffee in a biodiversity-friendly
manner (Bray et al. 2002; Philpott & Dietsch
2003). The recent efforts in Kodagu toward
organic coffee cultivation are steps in the right
direction. In addition to this, the market access
of certified products should be facilitated by
specific government policies and appropriate
legislation. We believe that the effective
marketing of biodiversity-friendly coffee in the
international market can complement the policies
and legislation. Such steps will promote shade-grown
coffee cultivation in Kodagu.


Conclusion

In many parts of the world the fate of biodiversity
is believed to depend on the forest remnants in
human-made landscapes (e.g., Brussard et al.
1992; Luck & Daily 2003; Rosenzweig 2003).
It is recommended that conservation measures
in agricultural landscapes should include stepping
stones of native woodlands for maintaining diversity
(e.g., Schwartz 1997; Pirnat 2000; Duelli & Obrist
2003) and gene flow (Bawa & Ashton 1991; Hannah
et al. 1998; Rouget et al. 2003). In recent years,
the conservation community has come to realize
that the long-term survival of biodiversity depends
on the effectiveness with which landscape between
the forest remnants can be managed (Gould 2000;
Faith & Walker 2002; du Toit et al. 2004). Our
results suggest that maintaining the integrity of
coffee plantations is necessary for conserving
biodiversity of sacred groves in Kodagu. A patch-scale
study alone is insufficient to understand the role
of sacred groves; a landscape approach is essential.
Involving local people in management is also key
to successful biodiversity conservation because
of the anthropogenic nature of this landscape.
The government must ensure that their
policies favor local planters so as to promote
biodiversity-friendly coffee cultivation.

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