PRIORITISATION OF FORESTS FOR BIODIVERSITY CONSERVATION

Role of endemism in conservation priorities: Species richness and endemism are two key attributes of biodiversity that reflect the complexity and uniqueness of natural ecosystems (Caldecott et al, 1996). Myers et al (2000) strongly favour identification and prioritisation of `hotspots', or areas featuring exceptional concentrations of endemic species and experiencing exceptional loss of habitat. Their focus is more on species, rather than populations or other taxa, as the most prominent and readily recognizable form of biodiversity. Concentrating a large proportion of conservation support on these areas would go far to stem the mass extinction of species that is now underway.  Nelson et al (1990), based on forest studies in Brazilian Amazonia, realized the importance of locating true concentrations of plant endemism for selecting priority conservation areas to guarantee preservation of unique species. A study on 19 species of endemic mammals and birds in Mexico made Peterson et al (2000) favour setting of regional conservation priorities based on combinations of modeling individual endemic species' distributions, evaluating regional concentrations of species richness, and using complementarity of areas by maximizing inclusion of species in the overall system. The optimized reserve system identified by this approach is stated to have performed 33–58% better than existing protected areas in inclusion of the endemic species. Therefore they favoured making necessary adjustments in the existing systems through incorporation of endemic areas. Strengthening such observations Stattersfield et al (1998) conclude that the 218 endemic bird areas identified by Birdlife International provide a reasonable overlap with the biodiversity hotspots identified by other conservation organisations, and are a focus for conservation action. Burlakova et al. (2011) advocated the need for adopting species rarity and endemism in aquatic domains also for the conservation of regionally rare and endemic fresh water molluscs in Texas. 
Reviewing the role of endemism, Meadows (2008) stated that ecoregions rich in endemics are also rich in overall species.  For example, the 10 percent of the world’s land area with the most endemics also has more than 60 percent of all terrestrial vertebrate species. Likewise10 percent of land with the greatest number of endemic amphibians and reptiles also contains more than 70 percent of all terrestrial vertebrate species. In addition, ecoregions rich in endemics of any one vertebrate class are also rich in endemics of the other three classes. At the same time many researchers on vertebrate conservation also content that their findings may not apply to nonvertebrates and that endemism is only one criterion for planning. However, using endemism along with other factors to identify global priorities focuses conservation in critical regions, where on-the-ground efforts will yield the greatest payoffs for biodiversity.
Humid tropical forests, like the rain forests, are richest systems in biodiversity. Regions of high rainfall also have large volumes of water in the river flow (World Water Assessment Programme, 2012). The confluence of rainforests and hydropower potential have prompted  many nations with large areas of tropical rainforest -including Brazil, Peru, Colombia, the Democratic Republic of the Congo, Vietnam, and Malaysia - plan to expand their hydropower energy capacity. It is generally assumed that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Study in the Xingu River basin of Amazonian Brazil using hydrological and climate models showed that simulated deforestation of 20% and 40% within this basin increased discharge by 4–8% and 10–12%, which could make similar increases in energy generation from a very large hydropower station planned in the river. When indirect effects were considered, simulated deforestation inhibited rainfall in the Xingu basin by 6 to 36%, thus offsetting the likely gains (Stickler et al., 2013). Moreover the loss of top soil and landslides and sedimentation in the downstream areas following deforestation are also to be considered. Forest decline can as well upset microclimate conditions and cause disappearance of scores of sensitive species.
The Western Ghats together with Sri Lanka constitute one of the 34 Biodiversity Hotspots of the world in view of exceptionally rich biodiversity, high degree of endemism and at the same time undergoing tremendous threat from human activities. The original extent of this combined Hotspot was 189,611 km². Of the hotspot vegetation what remains today is merely 43,611 km² area. Tremendous population pressure and biomass needs have created heavy fragmentation of Western Ghat forests. Both these regions in this hotspot together continue to shelter still 3,049 endemic plant species, 10 endemic  threatened birds, 14 endemic threatened mammals, 87 threatened amphibians and so on (Conservation International, 2013).
Protected Areas in Uttara Kannada: Karnataka has five National Parks and 21 Wildlife Sanctuaries.  Uttara Kannada district has mainly two important protected areas namely Anshi National Park and Dandeli Wildlife Sanctuary. These two PAs are brought together under Dandeli-Anshi Tiger Reserve with focus on tiger conservation. The DATR presently covers an area of 1365 sq.km. in the taluks of Joida, Haliyal and Karwar. Admittedly, we were not given permission to carry out forest ecological studies within this Tiger Reserve. Hence we have relatively lesser sampling areas within these taluks. Recently (in 2011) Attivery Bird Sanctuary was declared in Mundgod taluk covering 2.23 sq.km area, mainly composed of a reservoir and its peripheral areas.
Conservation Reserves are a new concept under the framework of Protected Areas under the Wildlife (Protection) Amendment Act of 2002. These reserves they seek to protect habitats that are under private ownership also, through active stakeholder participation. They are typically buffer zones or connectors and migration corridors between National Parks, Wildlife Sanctuaries and reserved protected forests in India. They are designated as conservation reserves if they are uninhabited and completely owned by the government but used for subsistence by communities, and community reserves if part of the lands are privately owned. Administration of such reserves would be through joint participation of forest officials and local bodies like gram sabhas and gram panchayats. They do not involve any displacement and protect user rights of communities. In Uttara Kannada, some such Conservation Reserves were set up by the Government of Karnataka, under the intiative of the Mr Anant Hedge Ashishar of Western Ghat Task Force, the Karnataka Forest Department, ATREE and SACON with technical inputs from Mr. Balachandra Hegde. Presence of endangered and endemic species, critical corridors connecting larger Western Ghats landscape and potential threats for the region etc., were considered for identifying conservation priority areas (Dandekar- http://sandrp.in/rivers/Novel_Conservation_reserves). Four such reserves were set out to protect Lion tailed macaque habitats, rare and endangered Myristica Swamps, Hornbill habitats and a riverain ecosystem (details are given in Table 6 and Figure 15)

Figure 15. Protected Areas of Uttara Kannada

7.1 Assigning conservation values through correlation between five notable parameters of tree communities in Uttara Kannada
To be helpful in preparing a composite conservation index for forest patches studied through 116 transects and covering the entire district we considered five important variables (% evergreenness, % endemism, basal area, tree height and Shannon diversity index) that were studied about these samples. The relative importance of these variables in assigning conservation values, based on the 116 sample studies is depicted in Figure 16. Some notable points on these variables are given below:
Evergreenness: Evergreen forests of the Western Ghats, due to various reasons, such as seats of high endemic diversity and high hydrological value is an important factor for assigning convservation values. We have considered here percentage of evergreen trees in the total tree population of the sample as evergreenness.

Figure 16. Relative importance of tree community parameters for assigning conservation values (n=116, P< 0.0001)

Endemism: Tree endemism is of overall importance in for assigining conservation values. Through an earlier study in the Western Ghats it was established that forest evergreenness in a stand, is a strong positive determinant of tree endemism in the same stand (Chandran, 1997). The find was carried forth beyond into the domain of endemism among fresh water fishes in the streams of Sharavathi River catchment (Sreekantha et al, 2007) establishing that the number and percentage of endemic fishes among total fish fauna in a stream was directly correlated to the percentage of evergreenness and tree endemism in the catchment area forests of that particular stream. In Uttara Kannada amphibian studies highest species diversity (35 species), with high percentage of Western Ghat endemism (26 species, 74% endemism) occurred in a mere 2.25 sq.km area of high evergreen forests (almost 100%) characterised by Myristic swamps in Kathalekan of Siddapur taluk (Chandran et al., 2010).
Tree heights: World over tallness of forest stands is considered indicative of the old growth nature and merits high conservation value. Human impacts on tall forests through logging, either clear felling or selection felling would result in regenerated trees of lesser heights, as the competition for light is minimised.
Basal area: Basal area of trees per hectare expressed sq.m is a standard expression in forest ecological studies worldwide about the relative growth of forests. It is a major factor for estimating forest stand biomass and therefore also for estimation of carbon sequestration.
Diversity value: It is generally accepted that higher diversity in general goes hand in hand with conservation importance.
It is evident from the analysis that the highest correlation (0.89) was between ‘% endemism’ and ‘% evergreenness’. This can be also justified from the fact that those transects which have 50% or more endemism have evergreenness values as high as 90% and more (Table 5). This was followed by the parameters basal area, tree height and Shannon diversity with which it had correlation in descending order of 0.51, 0.48 and 0.39 respectively. The percentage endemism is the most decisive factor in conferring higher conservation value to any ecosystem as endemics lost in their respective regions are irreplaceable. Higher endemism in a particular area indicates the presence of high sensitive species in that area, implying that there should be greater prioritisation in the conservation of endemic areas in any conservation programmes, not sidelining in any way the importance in conservation of any widely distributed but threatened species like elephant or tiger. The tree height and basal area can also be considered as factors contributing to the overall conservation value of the forest areas.
Principal component analysis: A PCA of the sample sites was carried out considering the observed and quantified characters of tree communities viz. evergreenness, endemism (of Western Ghats), height and basal area. The PCA (Figure 17) shows that the first two axes accounted for 86.57% of the cumulative variance explained by the four gradients extracted in the PCA analysis and the direction and length of each arrow indicated the direction and rate of maximum changes in each variable. The Eigen value for the first axis was 2.53, whereas for the second axis it was 0.92. The loading scores obtained in PCA also indicated that the prime factors influencing the forest vegetation are evergreenness and endemism than the height and basal area in first axis (Table 3). The high evergreen/endemism rich areas also host many rare and threatened species and essentially need to be prioritised for biodiversity conservation.
In a scheme of ranking sites representative of forest patches, areas of high tree endemism- which are essentially high evergreen areas, degree of endemism needs to be conferred higher value than height or basal area/ha. The latter two are, in the conditions of Uttara Kannada, much dependent on the degree of protection that a forest patch enjoys. Even moist deciduous forests, can attain much height and high basal area, but  tree endemism (of Western Ghats) is scanty here even in the absence of human disturbances.  At the same time height factor cannot be ignored in evergreen forests as we hardly get threatened tree species like Dipterocarpus indicus, Myristica magnifica, Syzygium travancoricum etc. in any dwarfish evergreen forest. Being on the positive side of conservation both height and basal area are to be given a proportionate score or rank points while preparing a composite index for conservation. Most of the areas which are negatively correlated with evergreen and endemism axis are mostly degraded areas or deciduous forests with hardly any Western Ghat tree endemism. The presence in the Western Ghats of a variety of life forms such as very sensitive fauna like endemic amphibians, fishes, birds or butterflies etc. and endmic primate like Lion-tailed macaque is dependent on forest evergreenness and tree endemism.  Recognizing the relative importance of high tree endemism (reflecting degree of evergreenness of the forests), forest canopy heights and basal areas/ha, on the basis of PCA carried out, we have formulated a conservation prioritisation scheme. The rationale for ranking is based on a cumulative score based on the relatively higher importance of endemism, followed by height and basal areas. In assigning conservation scores for each transect sample we have added the loading scores from Table 7 for each of the three parameters considered viz. endemism, height and basal area. These scores are in addition to a value assigned to threatened tree species (highest for Critically Endangered, followed in importance by Endangered and Vulnerable species). Also taken into consideration is the value for diversity index (Shannon-Weiner) of each transect?

Figure 17. PCA scatter diagram represents four variables with 116 sampling sites

7.2 Evolving criteria for a composite index for forest biodiversity conservation assessment in Uttara Kannada
For major mammals like tigers, elephants and such flagship species the Dandeli-Anshi Tiger Reserve, composed of Anshi National Park and Dandeli Wildlife Sanctuary, together cover 1365 sq.km or 13.3% of the district itself. The DATR already covers good parts of Joida and western parts of Haliyal taluks and interior parts of Karwar taluk towards the Anshi Ghat. The forests covered under its domain include evergreen to semi-evergreen, moist and dry deciduous and savannah and scrub as well. We were not successful in getting necessary permission to make studies in this wildlife rich protected area. Such restrictions were not faced in Conservation Reserves and other administrative categories of forests. Now that we have already made 116 sample transects in the district and gathered data on the plant species diversity for each sample area, basal area, biomass, estimates of carbon sequestration, percentage of evergreenness and Western Ghat endemism and about the distribution of threatened species etc. we have attepted here to formulate a scientific basis for ranking of each representative sample site, through value assignments given to the key parameters viz. 1. Endemism (reflects evergreenness of the forest stand); 2. Basal area of trees (indicator of biomass and carbon sequestered), 3. Canopy height; 4. Diversity index and 5. Presence of threatened tree species (based on IUCN Red List)
7.3 Criteria selection and assignment of scores for evolving composite conservation ranking of forest patches (Table 8 for details):
Tree endemism: One of the prime reasons for Western Ghats constituting a Global Biodiversity Hotspot along with Sri Lanka is the high degree of endemism in the flora and fauna. As % of tree endemism is strongly linked to % of evergreenness, considering both the parameters for assigining scores would amount to bias against other parameters for evolving composite conservation index. We have assigned a score for tree endemism starting with a minimum of 5 for 20-30% endemism for a sample adding additional 5 points for every 10% interval.
Basal area: From a starting minimum score of 5 points for 20-30 sq.m basal area/ha  2 additional points are given for every 10 sq.m addition in basal area (30-40 sq.m, 40-50 sq.m and so on). The assignment is made bearing in mind the fact that selective logging of trees and other forms of extraction of biomass can reduce the basal area even for a high diversity forest rich in endemism
Average height of trees: Most of Uttara Kannada falling in the high rainfall zone, except Mundgod and eastern parts of Haliyal and Yellapur, would support high statured trees, the tallest emergent exceeding 30 m and the lesser ones attaining anything from few meters to over 20 m. We have estimated the height of each tree within transect cum quadrat samples and arrived at the average height per sample. Undisturbed forests tend to have more heights than disturbed and secondary forests or savannas. As tall statured forests have greater conservation importance than dwarfer ones we have assigned a score ranging from a minmum of 5 for average tree height of 14-15 m with addition of 2 points for every 1 meter increment.
Diversity: A minimum score of 5 points has been given for Shannon-Weiner diversity index of 1-2, 7 points for 2-3 and 9 points for 3-4.
Threatened species: Presence of any IUCN Red Listed tree species in any forest sample, notwithstanding any other parameter considered here automatically raises the conservation importance of that forest.  This is despite the fact that many tree species are yet to be evaluated for their rarity by the IUCN. We have assigned 30 points for each Critically Endangered tree species, 20 points for an Endangered species and 10 points for a Vulnerable species. Any new tree species described from the forest in particular will gain for the hosting site yet another 30 points.
Additional value: As it is difficult to rank an ecosystem sample holistically as many features go undervalued or unconsidered for ranking all sites have been uniformily given an add value of 20 points (Table 8 for ranking criteria). Results of application of the composite ranking system for forest conservation adopted here is presented in Table- 9.


Table 8. Criteria for composite index for biodiversity conservation importance ranking in Uttara Kannada

Parameter		Score	Parameter		Score
Average height (m)	14-15	5	Basal area (m²)	20-30	5
	15-16	7		30-40	7
	16-17	9		40-50	9
	17-18	11		50-60	11
	18-19	13		60-70	13
	19-20	15		70-80	15
	20-21	17		80-90	17
Endemism%	20-30	5	Threatened species	Vulnerable	10
	30-40	10		Endangered	20
	40-50	15		Critically Endangered	30
	50-60	20		New species	30
	60-70	25
	70-80	30
	80-90	35
Diversity index (Shannon)	1-2	5
	2-3	7
	3-4	9
Add value for all transects		20

 

Table 9.  Composite conservation index, based on total site ranking score, for 116 forest samples