CASE STUDY

Ecological Restoration of Lantana-Invaded Landscapes in Corbett Tiger Reserve, India

Suresh Babu, Amit Love and Cherukuri Raghavendra Babu

ABSTRACT Lantana {Lantana cámara), one of the world's most troublesome invasive weeds, has become a menace in most of the protected areas located in tropical and subtropical belt of India. The lantana-infested landscapes not only are impov- erished as habitats of wildlife but also contribute to human-wildlife conflicts owing to diminished ecosystem services. This paper is a case study of successful eradication and restoration of two lantana-invaded sites in Corbett Tiger Reserve, India. A method for eradicating lantana was developed using knowledge about its ecology, and, subsequently, weed- free landscapes were restored to productive grasslands and mixed woodlands using native . The restoration of these areas to grassland communities has successfully prevented secondary invasions by lantana and other weeds and has enhanced the habitat quaiity for herbivores whose populations are vital for the survival of top carnivores such as tiger {Pantheta tigris corbetti).

Keywords: Corbett Tiger Reserve, ecological restoration, grasslands, lantana (Lantana camera), protected areas

ndia's first national park, Corbett these PAs, the peripheral buffer zones has demonstrated allelopathic poten- INational Park, was declared in 1936. (which act as buffers from develop- tial and can considerably reduce tbe Ever since, there has been a steady mental and other human activity) and seedling vigor of native species (Gentle rise in India's Protected Areas (PAs), forest gaps (firelines, forest guard quar- and Duggin 1997, Day et al. 2003). which include National Parks, Wild- ters, etc.) in the core areas are invaded It infests disturbed forest ecosystems, life Sanctuaries, and Tiger Reserves, by non-native invasive species. Tlie where it dominates understory species, especially after the enactment of the worst invasive weeds of PAs include blocks natural succession, reduces bio- Wildlife Protection Act in 1972. In lantana (Lantana cámara)^ bittervine diversity, outcompetes native pasture 1988, there were 54 national parks [Mikania micrantha), thoroughwort species, reduces productivity, increases and 372 sanctuaries covering a total [Chromolaena sp.), tropical whiteweed soil erosion, and causes illness and area of 109,652 km^. There are cur- {Ageratnm conyzoides), Santa Maria death of livestock (Sankaran 2007, rently about 597 national parks and feverfew {Parthenium hysterophorus), Walton 2006). The dense under- sanctuaries in India, and these cover and pignut [Hyptis suaveolem). story of lantana inhibits the seedling 134,572 km-', or 4.74 percent ofthe Lantana is one ofthe worlds 100 recruitment of native tree species in country's geographical area. Launched worst weeds and is invasive in over 60 tbe forest, leading to the depletion of in 1973 with nine reserves covering countries, particularly in tropical and native trees (Singh er al. 1995, Sharma an area of 16,339 km^, the Project subtropical regions outside its native et al. 2005, Bhatt et al. 1994, Kohli et Tiger program has been extended to range in the neotropics (Walton 2006). al. 2004). It has invaded the majority 28 reserves in 18 states, encompassing It is a low, erect or subscandent peren- of Indian pasturelands (13.2 million 37,761 km- of tiger habitat. However, nial growing to a height of 2.5 ha) beside other areas, and the cost of the management of these protected m or more and forming dense mono- its control is estimated to be USS70 areas is a major challenge with prob- cultures. It reproduces primarily by per hectare (Singh 1996). Tbercfore lems of habitat fragmentation, man- means of copious seed production and the damage from lantana to pastures wildlife conflicts, poaching, forest also by vegetative propagation from alone is estimated to be US$924 mil- fires, and invasive species. In most of cut stems. The juicy pericarp attracts lion per year (Pimentel et a!. 2001), a large number of dispersal agents, and this does not include vast tracts of Ecological Restoration Vol. 27. No. 4, 2009 among which birds play a major disturbed forest colonized by lantana. ISSN 1522-4740 E-ISSN 1543-4079 role. Tbe can grow individu- It is not clear how it arrived in India; ©2009 by the Board of Regents of the ally as clumps or form dense thickets neither is it known when it reached University of Wisconsin System. crowding out the native species. It Corbett National Park, although there

December 2009 ECOLOGICAL RESTORATION 27:4 467 are anecdotal references to introduc- ecosystems. In this paper, we present grasslands. The diversified vegetation tion of lantana as an ornamental in our observations and experiences on types support a healthy population of the early 20th century near Nainital. the eradication of lantana, its control, herbivores and carnivores including Lantana might have been introduced and ecological restoration of lantana- the riger. in India on multiple occasions in late eradicated areas in CTR. Ihe buffer area of the park includes 1800s—as an ornamental in Coorg several villages where lantana was (Hiremath and Sundaram 2005) and Study Area introduced as a hedge to protect as biohedge in Calcutta in the early the crop fields from herbivores. Over 19th century (Hakimuddin 1929, Corbett National Park is the oldest time since its establishment, there has Pereira 1919). Hakimuddin (1929) National Park in India, located been an increase in human-wildlife also gives an account of its introduc- between 7S°5' E and 79''5' E longitude conflicts, due mainly to large livestock tion and spread in Nainital District and 29"25' N and 29^40' N latitude maintained by the few villages located around 1905. Per this account, it was (Figure 1) in the state of Uttarakhand. in rhe buffer area. There were frequent confined to hedges and bad sparse Corbett Tiger Reserve was created instances of catde grazing within tbe distribution until 1911, but by 1929, with the National Park and additional park areas and thus competing with lantana had spread from its point of Reserve Forest area as part of the nine other herbivore populations. Ihere introduction to about 40 km in all Tiger Reserves created at the launch were also several instances of wild- directions, forming dense thickets ofProject Tiger in 1973, with the spe- life raiding the agricultural fields and covering farms, pastures, fallows, and cific aim of saving the dwindling tiger cattle takings by tigers and leopards. forest areas. population. The CTR spreads over an As per government policy at the time, Frugivorous birds are known to play area of 1318.5 km^ in the foothills there was pressure to expand the PA a major role in the dispersal of fleshy- (Shivaliks) of northwestern Himalaya and to relocate the villages with their fruited invasives (Gosper et al. 2005, in the Siwalik-Terai biotic zone of the growing livestock herds. As villages Buckley et al. 2006), and they may Indian Himalayan ranges. The reserve were relocated from within the PA to have dispersed lanrana from villages is adorned with a unique assemblage elsewhere, large tracts of lands once and townships, where it was grown as of Himalayan flora and fauna and well cultivated or settled were rapidly a hedge plant, to the disturbed forest known for a healthy population of invaded by lantana (Sahu and Singh tracLs in tbe periphery of Corbett tigers. In 1991, an area of 797.72 km^ 2008) and other weeds. In 1990-93, Tiger Reserve (CTR), particularly was added as buffer for the Corbett Dhara and Jhlrna, two villages .situ- intensely grazed habitats. Today, it Tiger Reserve and includes the whole ated on the southern boundary of the has invaded all the plant communi- of Kalagarh Forest Division and 96.70 reserve, were relocated to the Firoz- ties, ranging from gra.sslands to moist km^ of Ramnagar Forest Division. The pur-Manpur area and Ampokhra, deciduous forests, of CTR—in both CTR management is headed by the situated on the Ramnagar-Kashipur the buffer areas and several patches in Field Director with headquarters at highway. Another village, Laldhang, the core area. Ramnagar. located along the southern boundary Despire a fairly large amount of The area was declared as a National of the park is presently being relo- published literature on the , Park not only becatise of its biological cated. These villages have been relo- biology, ecology, and control and richness and as prime tiger habitat but cated outside the park to aid conser- management of lantana. no successful also because of its hydrological func- vation programs, and the areas thus strategy for control and management tion as a principal catchment area of vacated have been included in CTR as is available. The landscapes colonized the Ramganga River, a tributary of buffer zones. If was expected that the by lantana are degraded ecosystems the Ganges. The landscape of Corbett forest would regenerate; but as years and pose several challenges for resto- encompasses a network of monsoonal passed, no significant forest regen- ration, including means of removing and perennial first-, second-, and eration occurred, as the native spe- invasives and augmenting ecosystem third-order streams having wide riv- cies were outcompeted by weeds. At redevelopment. We have attempted to erbeds and riverine stabilized islands, present no villages remain inside the tackle the problem of lantana in CTR floodplains, valleys, gentle hillslopes, Tiger Reserve, but there are 92 villages witb a three-step approach: 1) under- hilltops, and marshlands. These dif- within 2 to 3 km of its boundary. The standing the biology of lantana with ferent habitats support a wide range human population of these villages is the objective to develop control mea- of communities, ranging from serai around 65,982, and the livestock pop- sures; 2) developing simple and effec- grassland communities, shrublands, ulation around the reserve is 44,416 tive control measures; and 3) evolv- and moist and dry deciduous forests (Ministry of Environment and Forests ing a suitable restoration program, with sal {Shorea robusta) as the domi- 2001). ITierefore there is persistent keeping in view the requirements of nant tree to patches of mixed decidu- pre.ssure on the Park's boundary from the stakeholders and the reference ous forests, bamboo thickets, and these villages. The need is strong to

468 December 2009 ECOLOGICAL RESTORATION 27:4 To Lansdowne

To Marchula

CORBETT NATIONAL PARK (CORE ZONE) RESERVE FOREST (BUFFER ZONE) SONANADI WILDUFE SANCTUARY

RESERVOIR AND RIVER

ROAD NETWORK

U\LDHANG

Figure 1. Schematic map of Corbett Tiger Reserve (A) and satellite Image of the inset from Google Earth (B) showing the experimental plots at Jhlrna and Laldhang.

December 2009 ECOLOGICAL RESTORATION 27:4 469 restore even the buffer zones that are Some of these methods do bring both sites, 2 ha rectangular plots were impoverished by lantana, to meet the about a short-term reduction in lan- demarcated and initial conditions were purpose for which they were created. tana cover. But with the onset of recorded (Figure 2A) and subsequently Dwindling prey base and human- monsoons, profuse coppicing from used to develop a control and manage- wildlite conflicts are considered the multiple growing points triggered by ment strategy. We studied the field prime causal factors for the dwindling the suppression of the apical meri- biology and ecology of lantana wich a population of tigers in the wild across stems takes place, and soon lantana view to developing an effective control the country (Seidenstickerei al. 1999, overshadows the gtound, preventing and management strategy. The aspects Johnsingh and Negi 2003, Johnsingh the germination and establishment investigated include 1) magnitude of et al. 2004). For a long time the man- of other species, particularly natives. the invasion; 2) distribution of growth agement was not serious about the Clipping is totally ineffective and points (vegetative reproduction); 3) infestation of che park with lantana only causes the clumps to spread and characteristics of the root system; and on the grounds that it serves as a food become hardier. Burning results in 4) seed production, modes of seed base for some species of birds. How- coppicing from the buried meriste- dispersal, and seed germination. ever, the park managers have now real- matic zone and also increases soil ized that the spread of lantana in the erosion. Burning on a large scale is entire park is changing the landscape, normally not resorted to in PAs, as the Field Biology and threatening its biodiversity, preventing fire may spread to adjoining areas and Ecology of Lantana natural succession, and enhancing the because some varieties have a climbing frequency of human-wildlife conflicts habit and can cause crown fires. Grub- Magnitude of Invasion owing to increased crop raiding by bing, besides being labor intensive, of Lantana in CTR herbivores in nearby villages. disturbs the soil, which exposes the A survey of core and buffer zones of buried seeds of lantana and leads to the park was carried out using strati- their rapid germination. The conse- fied random sampling to assess the Traditional Controi quence of most of these methods has magnitude of invasion and to under- Methods generally been vigorous regeneration stand the vulnerability of different of lantana. A number of methods, including habitat types to iantana. In each habi- physical, chemical, and biological In another attempt to controi tat type studied, a total area of 0.5 methods, have been used to control lantana in CTR, giant reed {Amndo ha was sampled using 10 m x 10 m and manage lantana invasions in dif- donax), a perennial grass, was planted quadrats (« = 50) spread randomly ferent countries. Day and colleagues in one of the lantana-infested areas in across the habitat. (2003) summarized the status of cur- the core area of the park after burning. We observed that lancana was found rent control methods as inadequate Within flve years, the giant reed-Ian- everywhere except in dense, closed and infeasible owing to the sheer size tana comtnunity became dominant forests and the percent relative den- of the infestations, low land values, in the area, with both species spread- sity (the ratio of density of lantana to and lack of incentives for control. The ing to new areas. It was realized sub- the density of all plants in the 0.5 ha biology of lantana and lack of site- sequently chat giant reed itself is an sampled) varied from 0.1 % to 82.3% specific information on its ecology invasive species and is not preferred (Table 1). The stands along forest are major bottlenecks in developing by herbivores. The current spread of roadsides comprised only old clumps, effective tools for ¡cs miinagemenc. It lantana all over the CTR demonstrates and no new saplings or young plants has yet to be recognized, for instance, the ineffectiveness of the traditional were observed. Abandoned arable vil- that habitat degradation has triggered concrol methods in use for over two lage land fields also had a high relative the invasion of lantana and that a final decades. Our field observations of tra- density (22.9%) of lantana. Except for solution has to come in the form of ditional control measures raised che a few perching trees, no other native habitat restoration. In India, forest following cwo questions: Where and species were found in densely infested managers recognize lantana infestation how does proliferation occur after clip- areas. in PAs as a major problem, and they ping, chopping, or burning? What are are currendy using a variety of control che modes of seed dispersal in lantana Distribution of Growing Points methods. The physical methods diat and how does ic colonize new areas? We examined the growth partern of have been in practice for controlling To address che cwin challenges 25 individual lantana three months lantana include 1) chopping the main posed by lancana invasion—those of after each of the following treatments: stem at the base; 2) clipping aerial its control and habicat degradation, 1) chopping at about three-fourths shoots 10 to 30 cm above the base; 3) we selected two relocated village areas, of the height of the plant (leading to burning the clumps; and 4) grubbing Jhirna and Laldhang, in the buffer about 25% removal at about 1.5 m (total uprooting). zone of CTR as our study sites. At from the ground); 2) chopping down

470 I* December 2009 ECOLOGICAL RESTORATION 27:4 Figure 2. Photo series of treatment plots: A) massive original colonization by lantana in Jhirna; B) secondary invasion of the same plot after removal of lantana: C) the same plot ot jhirna, two years after restoration with selected legumes and grasses; and D) and after three years of restoration; E) restoration plot at Laldhang showing development of grasslands two years after lantana removal; and F) same plot with grasslands and scattered shrubby legumes after tbree years. Photos by Suresh to the base; 3) burning; and 4) conrrol. the aerial growing points. It is interest- independent plants when connection Growing points are located from rhe ing to note that the subterranean cop- with the main plant is severed. This is lowest node to the uppermost node of picing zone was most active when the the only method of vegetative repro- the main stem and lateral branches. aerial growing points were removed duction we observed. No root suck- The meristematic zone, located at the by complete chopping or burning of ers were observed, and no fragments transition between stem and root, was the aerial biomass and least active in of aerial branches were found to be identified as the active coppicing zone naturally grown plants (Table 2). capable of rooting and developing into in lantana based on observations sum- The auxiliary shoots arising from plants. marized in Table 2. This zone is usu- the lowest nodes of the main stem ally buried in the soil (up to 10 cm are usually prostrate in their lower Root System depth). Coppicing was profuse irom halves, and rooting occurs at the Lantana has a shallow root system. The this zone after burning and chopping nodes on the prostrate portion of the first-formed taproot is stout, tapers at the ba.se, both of which remove al! stem. These shoots sometimes become gradually, and penetrates up to a depth

December 2009 ECOLOGICAL RESTORATION 27:4 I* 471 Table 1. Density and percent cover of lantana {Lantana cámara) across other studies also (Bhatt and Kumar different habitat types. Seedlings were not included in the survey. 2001). Therefore lantana has been able Landscape Density (ptants/m') % Cover to utilize the generalized mutualistic Riverbeds 0.0077 6.1 interactions in the invaded habitat for Stabilized riverine islands 0.0021 2.2 its spread and colonization. Floodplain without grasslands 0.0144 16.84 Tliese birds disperse the seeds Floodplain grasslands 0.0027 2.26 beneath perching trees, which are Forest roadsides 0.0909 82.23 mostly trees that provide shelter and Grasslands with perching trees 0.0072 7.18 have fruits of dimensions similar to Arable land abandoned by villagers 0.0126 22.05 lantana. We prepared a tentative list of Open forests with patches of grasses 0.0026 2.8 perching trees for the study area and Natural Gaps 0.0021 2.17 found large concentrations of lantana Dense closed forests with understory 0.0012 1.2 seedlings underneath these trees. The Marshy flatlands 0.0003 0.118 most common perching tree was ber Surface drainage channels 0.0048 1.12 {Zizyphus niimmulâria), a common fruit-bearing tree native to this region. Table 2. Growth pattern in lantana (expressed as mean number (± SD) of The dispersed lantana seeds are also shoots per coppicing region of the plant (n = 25) under different traditional carried by water along surface drain- control methods applied in mid-]une 2005; observations recorded in mid- age channels in the rainy season. Seeds September 2005 after three months of monsoon. deposited under perching trees and Chopped those carried by water currents usually Coppicing Region Chopped Burned Control from base germinate and establish seedlings. In Nodes in top one-third — 38.1 ±16.7 other words, the initial sites of lan- Nodes in middle one-third 18.4 ±8.2 — — 12.4 ±7.2 tana colonization are around perch- Nodes in lower one-third 28.5 ±7.1 — 18.3±5.1 4.3±2.2 ing trees, surface drainage channels, Root-shoot transition 12.5 ±3.8 61.8 ±10.2 42.7±15.4 1.8±0.6 and riverbeds, all of which are usually open habitats. It has been shown that of 0.2 m. From the upper portion of we estimated that over 1.2 million passage of lantana seeds through the the main taproot, stout lateral roots fruits are produced per hectare by gut of dispersers increases germination arise and some of these spread hori- pure stands of lantana in Corbett. rates (Mandon-Dalger et al. 2004), zontally in the topsoil. All along these This reproductive output highlights as is also the case with several other laterals, fine rootlets with copious root the tremendous potential that this spe- invasive species employing mutualists hairs are produced. The high invest- cies has for spreading into newer areas for their spread (Panetta and McKee ment in shoots rather than the root ofthe Park and the propagule pressure 1997). system suggests that the species utilizes it exerts on nearby habitats. Several attributes ofthe species that its energy more for vegetative growth We collected baseline data on dis- enable it to colonize disturbed habi- and reproduction. persal vectors of lantana because it tats have come to light. Of particular was crucial to understand the com- importance are the ability for vegeta- Seed Bioiogy plex patterns that may result from the tive propagation and employment Lantana reproduces primarily by seed interaction between lantana and its of generalist frugivores that use the and is a copious seed producer. The dispersal agents, as shown by earlier perching trees in the chaurs (grasslands seed is a pyrene (seed with stony endo- studies on Heshy-fruired invasive plant along floodpiains) for dispersal. We carp) enclosed within the sugary, juicy species (Glyphis et al. 1981, Stansbury also observed that seeds of lantana pericarp ofthe fruit, v^fhich is usually 2001, Renne et al. 2002, Buckley et failed to germinate in the absence of black in color and eaten by birds. The al. 2006). adequate sunlight and moisture. Any fruit, which ranges from 4 to 6 mm, So far, we have identified 18 spe- attempt to restore these invaded land- is available nearly throughout the year. cies of birds foraging on the fruits of scapes necessitates effective control The percent fruit set of plants, esti- lantana. These include common birds, measures that address the regenera- mated from the average number of such as the red-vented bulbul {Pycnon- tion ability ofthe species. The lantana fruits produced out of the average otus cafer), magpie robin (Copsychm density in different landscapes is such number of fiowers, was 68.95% in saularis), common myna [Acridotheres that any intervention limited to a the Jhirna area. On average, about tristis), and Indian cuckoo {Cuculus small area of the park is likely to be 1,660 individuals per hectare were micropterus). All these are generalist ineffective, as propagules would soon present in a pure stand of lantana. frugivores, and their roie in dispersal arrive from nearby areas. It must also From these empirical observations, of lantana seeds is implicated in some be followed up witb restoration using

472 December 2009 ECOLOGICAL RESTORATION 27:4 Figure 3. Stump of lantana removed by cut-root-stock method: A) root-shoot transition and emerging young shoots; and B) inverted clumps of lantana removed by this method, kept for drying. Photos by Suresh Babu competitive native species that can months). These dried clumps were about 20-50 clumps per day and the resist reinvasion by lantana and other collected in a small area for burning expenditure per hectare is about INR weeds. Following these insights from (Figure 3B). Subsequendy, perching 2,000-4,000 (US$40-$80)—in field biology and from other experi- trees were located and the saplings contrast to grubbing, where a single ences in controlling lantana (Day et al. were removed from under theiir can- laborer removes only 8-10 clumps per 2003), we developed a two-pronged opies and along the nearby surface day and the expenditure range is INR strategy—eradication and restora- runoff zone. Continuous monitoring 8.000-10,000 (US$170-$200) per tion—for the problem of lantana In was required in the area where lantana hectare. However, the cost of removal CTR and put this strategy to test at was eradicated, including manually per hectare varies according to the age the 2 ha plots at Laldhang and Jhirna. uprooting seedlings of lantana, if any, of the clumps, the terrain, and the for a year. The best time to eradicate density of lantana. Development of a Control lancana was in peak summer season As we observed in Corbett, simple Strategy and the Cut- when lantana clumps bear few or no removal of lantana by CRS method Root-Stock Method mature fruits. We realized that until was not enough. If cbe land was lantana is removed from all areas con- left vacant after eradication, it was Based on our studies of lantana in tiguous with the experimental plots, soon subjected to secondary invasion CTR, a simple, cost-eifective physi- the chances that the propagules would by invasive weeds like Santa Maria cal method has been developed for soon arrive was very high. Encour- feverfew [Parthenium hysterophorus). the removal and for long-term man- aged by the initial results of the CRS Senna tora, S. occidentalism llima {Sida agement of lantana infestation. The method, and with the objective to cordifolia), wireweed (5. acuta), and method was designated as Cut Root- completely remove lantana from all also lantana (Figure 2B). Therefore Stock (CRS) method, as it involved areas of CTR, the management under- we concluded that merely removing a cut below the root-stetn transition took massive scaling up, during which lantana will not solve the problem of zone (Figure 3A) identified as the lantana was removed in different parts ecological degradation of these areas active zone of proliferation for lantana of CTR including Dhikala, Gairal, and it is necessary to develop a suitable (CEMDE 2007, Pathak et al. 2006). Sarpadhuli, and Bijrani Ranges. restoration program for these weed- This method involved chopping The main advantage of the CRS free areas. the main taproot 3-5 cm below the method is that it does not involve ground surface with a few hits, using pruning of aerial branches or dig- Restoration of Weed- a kudaal (a locally available heavy ging and thus is less labor intensive. Free Landscapes digger) with a long handle. Then the ITiis method also results in very little clumps were lifted and placed upside regeneration of lantana by vegetative Our restoration technique consisted down to ensure that all the vegeta- propagation and fVom seed banks. A of four essential steps. The first tive parts dry up (a minimum of 2-3 single laborer can remove, on average. involved the identification of reference

December 2009 ECOLOGICAL RESTORATION 27:4 473 ecosystems by field ecological surveys legumes were mixed with farmyard removed by the CRS method failed in relatively undisturbed areas of the manure and soil, made into pellets, to germinate because the restored Park with similar ecological settings. and broadcast directly on the plots. A community strongly competed for After transect surveys (Krebs 1989) of mix of annual and perennial grasses light, and also owing to the crowd- the areas around Jhirna and Laldhang, was used, avoiding several species of ing effect. Continuous monitoring of v/e concluded that both areas are simi- grasses with invasive tendencies like the natural and manmade forest gaps lar to existing chaurs nearby and that cogongrass {Imperata cylindrica) and and landscapes that harbor perching it is most appropriate to develop these giant reed {Arundo donax). The den- trees, riverbeds, and surface drainage "lantana eradicated landscapes" into sity of tall grasses was kept low and channels for seedlings of lantana and grasslands and mixed woodlands. After high densities of nutritious legumes, their uprooting are essential for the referring to literature on the flora of like several species of indigo {Indigo- successfiil eradication of lantana. the foothills (Babu 1977, Pant 1976), fera spp.), flemingia {Flemingia spp.), we identified 28 grass species and 15 Aiylosia, and ticktrefoil {Desmodium legume species that have high for^e spp.), were maintained in the initial Results and Outreach value to herbivores, like {Axis stages. Subsequently, saplings of sev- The two plots established at Jhirna axis) and sambar {Cervm unicolor), eral native trees, particularly legumi- and Laldhang, using the integrated that form the prey base for carni- nous trees like albizias [Alhizia spp.), control and restoration strategy out- vores and also play a role in the early acacias {Acacias\i^.), Indian rosewood lined above, are now used for dem- succession In chaurs. {Dalhergia spp.), fruit-bearing onstration of the technique. At both The second step was to define target such as Zizyphus, and trees such as sites, the original relative density of conditions, and for this, the identi- alangium [Alangiurn javanicum), lantana clumps varied from 80% to fication of the requirements of the Assyrian plum {Cordia myxa), cham- 100% and were devoid of native spe- stakeholders (in this case the park ror {Ehretia laevis), and Syzygitim were cies except for a few scattered perching management) was a prerequisite. "The introduced in scattered patches. Plant- trees. Within two years of the restora- prime concern of the park manage- ings were carried out between July and tion program at CTR (June 2005 to ment was to augment the dwindling October (during the monsoon) every June 2007), both demonstration plots prey base for top carnivores like tigers. year. Legumes were introduced at six- harbored grassland communities with This could be achieved through the month intervals, as initial mortalities annual and perennial native grasses development of grasslands and mixed were high. and legumes. As of August 2008, seed- woodlands that would supplement the The fourth and the most important lings of several other native species are foraging requirements of herbivores. step involved monitoring and follow- also found as a part of the develop- Since both Jhirna and Laldliang are up activities such as manual weeding ing community, suggesting that the in the tourist zone of the Park, an under perching trees and along drain- habitat is improving (Figure 2C-F). indirect benefit was the ecotourism age channels. A list of the perching The recorded increase in the number potential of these areas. trees (candidate lantana dispersers) of species and the greater proportion The third step was the development based on field surveys was provided to of grasses and legumes in both plots of field nurseries and a sequential the field staff of the forest department. compared to the initial conditions are introduction of selected species into The most common perching trees in of particular importance (Figure 4). the lantana-free landscapes. A field the area are alangium, Assyrian plum, Tlie control areas had fewer species, nursery was established 3 km away sacred garlic pear {Crateva religiosa)^ having experienced some harvesting at Dhela, which had perennial water chamror, emblic {Phyllanthns einhlica)y as they are near the relocated villages. supply from a stream. Selected grass figs {Ficus spp.), gardenia {Gardenia It seems plausible that some of the species and their seeds were collected túrgida), glycosmis {Glycosmis pen- grass species may not persist over the from the buíFer areas within 5 km of taphylU), Miliusa velutina, Java plum long term on account of competitive the plots, along with several legumi- {Syzygium cumini), common jujube exclusion. nous species that are found locally. {Zizyphus jujuha [= Z. zizyphus]), As of August 2008, more than Propagules were transferred from this and jhar beri {Zizyphus nummuiaria). 150,000 grass clumps and more nursery to both the sites. Transplants This gready facilitated monitoring and than 5.000 saplings and seedlings of of grasses, consisting of a portion follow-up activities, even without the legumes were planted in CTR in areas of the rhizome having one to three presence of experts on-site to identify where lantana had been removed, culms, were planted at random with the species. The park management cir- covering an area of more than 1,600 a spacing of 8 to 10 cm. Saplings of culated this list to all the forest ranges hectares. Much of this effort was made legumes were raised in poly-bags and where the scaling up ot lantana con- possible only by active involvement of were planted on the plots. In the sub- trol and management was undertaken. Corbett management. At present the sequent year, the seeds of grasses and Lantana seeds buried under clumps follow-up activities involve monthly

474 December 2009 ECOLOGICAL RESTORATION 27:4 removal of seedlings, if any. Already there are very few seedlings arriving on these plots, and we believe that as nearby sources of seeds are removed and effective compecitors like grasses and legumes are present in adequate quantities; a reinvasion by lantana is unlikely. Ihe tree saplings have high survival rates (measured annually) because of modification of soil conditions and the habiciu by short grasses such as buffelgrass {Pennisetum ciliaris), sabai- Initial After 3 years grass [EuLiliopsis binata), tanglehead Laldhang [Heteropogoti contorttts), watercrown grass {Pííspalidium scrobiculûris), Ber- Figure 4. Comparison of species richness at the the two study sites following restoration. Control mudagrass (Cynodon dactylon), and sites wer« forested areas in the proximity of the experimental plots. Data on species occurence was collected using ten 100 m- quadrats at each of the sites. smutgrass {Sporobolus indicits), as well as leguminous species like salpani {Desmodium gangeticttm), threeflower Several workshops and hands-on the restored patches do noc require ticktrefoil {D. triflorum)., Flemtngia training programs were also held to aftercare like watering, since all the hracteata, R fruticosa, F. macrophylla, enable the foresters and park manag- species used are local. In CTR, the Indigofera astragalina., and rough- ers CO scale up the lantana control and approximate cost of removal of lancana hairy Indigo (/. hirsuta). The plots restoration measures, with field visits followed by restoration as described were browsed by chita! and there was to the plots and demonstration of the ranged from INR 6,000-9.000 some mortaliuj'. but it was not a .serious technique employed. Various aspects (US$125-$ 187) per hectare. How- impediment because herbivore num- of this model, including the costs and ever, across different PAs of Utta- bers were small, as most of the wildlife benefits of clearing lantana and then ranchal where this strategy was sub- had moved away from this area since it converting che landscape into produc- sequently followed, this method of had recently been a settlement. tive grasslands and woodlands, were restoration cost between INR 4,000- Both experimental plocs are now highlighted to gain wider acceptance 10.000 (US$83-$208) per hectare. fully covered with a carpet of sev- for the model. A simple manual was The range in cost is explained by the eral grass species and legumes, with developed and widely circulated to kind of terrain (rocky, slopes, alluvial scattered trees (Figure 2C—F). At aid the foresters in removing lantana soils, etc.) and the age of the clumps. Laldbang, the CTR management by the CRS method and to identify has scaled up the restoration plot to che grasses and legumes used in tbe Implications for 64 ha. In order to prevent repeated Corberc model. Management and encroachment and cattle grazing from Subsequently, noc oniy the CTR nearby villages, the management has management buc also other PA manag- Lessons Learned erected an electric fence around the ers of Utcarakhand State have adopted The PA network in India is the last entire plot until the grassland—mixed this model and are actively engaged refuge for a large number of threatened woodland community is established in this program at Rajaji National and endangered flora and fauna. It (at least another two years). Despite Park, Landsdowne Forest Division, provides a variety of ecosystem services this, droppings of chital and wild boar and Nainital Forest Division. Forest char support the enormous livelihood {Sus scrofa) have been observed in the departments of other states of India requirements of the country. One of fenced plot. Tiie Jhirna plot was left have also been convinced by the effec- the major problems faced by many unfenced because there was no threat tiveness of rhe approacK and have PAs in India today is habitat degrada- of cattle grazing, lliis plot is now fre- already removed lantana from several tion and fragmentation and subse- quented by large herds of browsers hundred hectares of forest land, partic- quent colonization of these disturbed like chital and sambar, which form the ularly around Panchmarhi Biosphere habitats by invasive species. The vast major prey base for carnivores. So far Reserve in Madhya Pradesh and tracts of forest and community lands there have been three recorded tiger Kalesar National Park in Haryana. covered by invasive weeds pose twin sightings at Jhirna in the vicinity of One of the major reasons for the challenges: control and eradication of the restoration plot. popularity of the CRS method has weeds and restoration of the weed-free been economics and the fact that landscapes to prevent fiarther invasions

December 2009 ECOLOGICAL RESTORATION 17-A 475 and improve habitat conditions. In et al. 1990, Jha et al. 1994, jha et Centre for Environmental Management this study, we examined the biology al. 1995), the present study further of Degraded Ecosystems (CEMDE). and ecology of lantana in order to emphasizes that although the broader 2007. Annual Report 2006-2007. New Delhi: Centre of Excellence Programme. understand its invasive nature, and theme of restoration is applicable for Ministry of Environment and Forests, based on that understanding, we any ecosystem, the approaches for res- Government of India. developed methods to eradicate lan- toration of degraded ecosystems are D'Antonio, C. and L.A. Meyerson. 2002. tana infestation and restore the land- inherently site and case specific. With Exotic plant species as problems and scape. However, as we learned with the mounting pressure on our natural solutions in ecological restoration: a syn- our experience in CTR, the ultimate resources, more and more ingenious thesis. Restoration Ecology 10:703-713. success of such a program banks heav- methods will have to be developed to Day, M., CJ. Wiley. J. Playford and M.P ily on the conviction and motivation restore the ecologically depauperate Zaiucki. 2003. Lanrana: Current man- of stakeholders. Landscapes degraded landscapes created by invasive species. agement status and future prospects. Australian Centre for International by invasive species are ofi:en extensive, Agricultural Research Monograph 102, and even as weeds are eradicated from Acknowledgments Gentle, C.B. and J.A. Duggin. 1997. Alle- one area, the propagule pressure can lopathy as a competitive strategy in per- This work has been carried out under the persist irom other areas. A well-coor- sistent thickets of Lantana catnara L. Centre of Excellence Programme of the dinated removal program followed by in three Australian forest communities. Ministry of Environment and Fotests, Gov- restoration at suitably large scales is Plant Ecology \32:%5~^5. ernment of India. We would like to thank Glyphis, J.P., S.J. Milton and W.R. Sieg- imperative to tilt the scales in favor of Mr. K.B. 'Iliampi, ICF, and Mr. Debasis fried. 1981. Dispersal oí Acacia cyclops native species (D'Antonio and Meyer- Jana, AIGF, of the National Afforestation by birds. Oci-o%tf 48:138-141. son 2002). A strong determination by and Eco-development Board, Ministry of Gosper. C.R., CD. Stansbury and G. Viv- the PA managers was crucial for the Environment and Forests. Government of ian-Smith. 2005. Seed dispersal of India, for constant support and encouragc- success of such a program. fleshy-fruited invasive plants by birds: menr. We would also like to acknowledge contributing factors and management The benefits of lantana eradication the extensive suppott we received from the options. Diversity & Distributions 11: and subsequent restoration to grass- Uttarakhand Forest Department, the Ghief 549-558. lands in CTR are many: enhanced Wildlife Warden, Dr. Srikant Chandola; Hakimuddin, M. 1929. Lantana in northern biological productivity, particularly in then Director of Corbett Nationai Patk and India as a pest and its probable utility terms of palatable species of grasses Tiger Reserve Mr. Rajiv Bhartari and his team; and the present Director, Mr.Vinod in solving the cowdung problem. Indian and legumes; greater retention of soil Singhal. Tlie assistance provided by Mr. Forester 5C>-AQ'>-A\Q. moisture; prevention of soil erosion; Pankaj Kumar and Mr. Harkesh Singh is Hiremath, A.J. and B. Sundaram. 2005. The enrichment of native biodiversity; also acknowledged. fire-lantana cycle hypothesis in Indian increased frequency of wildlife sight- forests. Cofiservation Society 3:26—42. ings; and enhanced recreational values Jha. P.K., S. Nair and C.R. Babu 1994. Development of an inexpensive legume- since CTR is a favorite place for eco- References Rhizobium inoculation technology tourists and ornithologists (Sankaran Babu, C.R. 1977. Herbaceous flora of Deh- which may be used in aerial seed- 2007). radun. New Delhi: Publications and Information Directorace, Council of ing, journal of Basic Microbiology 34: We anticipate that our observations Scientific Ô£ Industrial Research. 231-243. on lantana management in CTR and Babu C.R., P.K. Jha and S. Nair. 1990. Jha, PK.. S. Nair, M.C. Gopinathan and the success of the Corbett model will Biological reclamation of derelict lands: C.R. Babu. 1995. Suitability of rhizo- help in developing a similar manage- Problems and prospects. 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Johnsingh, A.J.T, K. Ramesh, Q. Quresh), the invader, soil, climate, the pres- ing after replacement of forest by lan- tana shrubland in Kumaon Himalaya. A. David, S.P. Goyal et al. 2004. Con- ent ecosystem condition, condition journal ofVegetation Science 5:67-70. servation status of tiger and associated of neighboring ecosystems, and most Buckley. Y.M., S. Anderson, C.P. Catterali, species in the Terai Arc Landscape. importantly, the requirements of the R.T. Corlett, T. Engel et al. 2006. Man- India. Wildlife Institute of India Report stakeholders. As is the case with our agement of plant invasions mediated by RR-04/001. earlier experiences on degraded land- frugivore interactions, Kohli, R.K., K.S. Dogra. D.R. Batish and scapes in the Himalayan region (Babu Ecology 43:848-857. H. Pal Singh. 2004. Impact of invasive

476 December 2009 ECOLOGICAL RESTORATION 27:4 plants on ihc struccure and composi- Agriculture, Ecosystems & Environment Singh, S.P. 1996. Biological control. Pages tion of natural vegetation of northwest- 84:1-20. 88-116 in R.S. Paroda, and K.L. ern Indian Himalayas. Weed Technology Renne, I.J., W.C. Barrow, L.A.J. Randall Chadha (eds), 50 Years of Crop Science 18:1296-1300. and W.C. Bridges. 2002. Generalized Research in India. New Delhi: Indian Krebs, C.I.1989. Ecological Methodology. 2nd avian dispersal syndrome contributes to Council of Agricultural Research. ed. Menlo Park CA: Addison-Wesiey. Chinese tallow tree (Sapium sehifentm, Stansbury, CD. 2001. Dispersal ofthe envi- Mandon-Dalger, I., R Clergeau, J. Tassin, Euphorblaceae) invasiveness. Diversity ronmental wcc¿ bridal creeper Aspar- l.N. Rivière and S. Gatti. 2004. Rela- and Distributions 8:285-295. agus asparagoides by silvereyes Zoster- cionships between alien plants and an Saliu. P.K. and J.S. Singh. 2008. Structural ops lateralis in south-western Australia, alien bird species on Reunion Island. attributes of lancana-invaded forest plots fma 101:39-45. Journal of Tropical Ecology 20:6^5-642. in Achanakmar-Amarkantak Biosphere Walton, C. 2006. Lantana cámara (shrub). Ministry of Environment and Forests. 2001. Reserve, Central India. Current Science Global Invasive Species Database. Inva- ProjectTiger: Status report. New Delhi: 94:494-500. sive Species Specialist Group (ISSG) of Government oflndia. Sankaran, K.V. 2007. Lantana cámara. Inva- the IUCN Species Survival Commission. Panctta, ED. and J. McKee. 1997. Recruit- sive Species Fact Sheet. Asia-Pacific www.i.«g.org/database ment of the invasive ornamental Schi' Forest Invasive Species Network, Food nus terebinthifolius is dependent upon and Agricultural Organization of the frugivores. Australian Journal of Ecology United Nations (PAO). wviAV.fao.org/ 22:432-438. forestry/media/13375/1/0 Pant, P.C. 1976. Plants of Corbett National Seidensticker, J., S. Christie and P. jack- Suresh Babu, Research Scientist, Centn Park, Uttar Pradesh. Journal of the son. 1999. Tiger ecology: Understand- of Excellence Progratn. Center for Envi- Bombay Natural History Society 73: ing and encouraging landscape pacrerns ronmerttal Management of Degraded 287-295. and conditions where tiger.s can per- Ecosystems, University of Delhi, India— Pathak, N., S. Basak. A. Ij)ve and S. Babu. sist. Pages 55-60 in J. Seidensticker, 110007, [email protected] 2006. Workshop manual for eradication S. Christie and P Jackson (eds). Riding of invasive weeds and habitat restora- the Tiger: Tiger Conservation in Human- Amit Love, Research Scientist, Centre of tion. Centre of Excellence Programme, Dominated Landscapes. Cambridge: Excellence Program. Center for Environ- Centre for Environmental Management Cambridge University Pres.s. mental Management of Degraded Ecosys- of Degraded Ecosystems, University of Sharma, G.P., A.S. Raghubanshi and J.S. tems, University of Delhi, India—110007 Delhi. Singh. 2005. Lantana invasion: An over- Pereira, W.E. 1919. Lanrana in the Math view. Weed Biology and Management Cherukuri Raghavendra Babu, Emeritus working circle in Savantavadi state 5:157-167. Professor, Centre of Excellence Program, forest. Indian /wrcíííT 46:188-193. Singh, A., V.S. Reddy and J.S. Singh. 1995. Center for Environmental Management of Pimentel, D., S. McNair,j.Janecka,J. Wight- Analysis of woody vegetation of Cor- Degraded Ecosystems, University of Delhi, man, C. Simmonds et al. 2001. Eco- bett National Park. India. Plant Ecology India—110007 nomic and envi ron men till threats of alien 120:69-79. plant, animal, and microbe invasions.

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