INVASION OF Parthenium hysterophorus IN CHIR-PINE FORESTS AND ITS ALLELOPATHIC EFFECTS

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1 INVASION OF Parthenium hysterophorus IN CHIR-PINE FORESTS AND ITS ALLELOPATHIC EFFECTS L. Q. Huy, Research Center for Forest Ecology and Environment - Forest Science Institute of Vietnam; CHEM TULIEM HANOI VIETNAM; quochuyle@hn.vnn.vn R. N. Seghal, Department of Tree Improvement and Genetic Resources, COF- UHF Nauni- Solan, (H.P.) INDIA; tgri@yspuniversity.ac.in April 24 ABSSTRACT: : Parthenium hysterophorus, an obnoxious exotic weed of unattended wasteland has now spread up into hills too. Presently the extent of its invasion into chir pine forests has been studied in three selected locations in distribution zone of the tree viz., Jepla (72m), Oachghat (135m) and Kiarighat (175m). Two canopy levels of chir-forest viz., open (2-35 stems/ha) and thin (35-5 stems/ha) were taken. Invasion of Parthenium hysterophorus was found in all the three locations and both the levels of forest canopy in Oachghat. Parthenium invasion was found to have significant effects on the herbaceous species with regard to their number of stem and cover ( =.5), but non-significant effect on the shrubs. In invaded areas, parthenium weed was found to be highly dominant among herbaceous species and usually with the highest IVI; 5.4 in Jepla, under open canopy & 83.7 under thin canopy in Oachghat and 88.6 in Kiarighat. There was significant difference of diversity index (H) between invaded and control sites observed for herbs, but non-significant difference recorded for shrubs. At the invaded site in Oachghat, H of herbs was found to be lower under open canopy as compared to the thin canopy, while SR was higher under open canopy and lower in thin canopy (those of control site were almost the same). Invasion of parthenium has either replaced important native grasses viz., Chrysopogon montana and Dicanthium annulatum which were once abundant in the chirforests in many places in Oachghat and Kiarighat, or significantly changed natural distribution pattern of herbs in case of Jepla,. High IVI of P. hysterophorus is due to allochemichals and high adaptation in reproduction & regeneration potential (Kohli and Rani, 1994). Parthenium seedlings in pots show strong allelopathic effects on seed germination in chir pine. One seedling in a pot reduces germination rate down to 17.8% lower than control. Reduction with 2 seedlings is by 35.6% and with 3 seedlings by 43.4% (P=.95). Key words: P.hysterophorus, allelophathy, IVI (Importance Value Index), Chir-pine (P. roxburghii), exotic weed Introduction. Parthenium hysterophorus L. is a member of the Asteraceae family and originally native of West Indies & Tropical America. This is an obnoxious exotic weed that has established itself almost throughout India. Though a weed of unattended land, it has now become a serious environmental and agricultural problem, besides being a health hazard for humans. Its worldwide distribution has been described in detail. The countries where it has been reported with the presence of this weed are South Africa, Mozambique, Madagascar in Africa, China, India, Vietnam, Nepal in Asia, Guatemala, Honduras, Belie etc. in Central America, Mexico, in South America and in United States ( Aneja, et al. 1991); (Kohli & Rani, 1994). P. hysterophorus possesses a very high invasive potential and quickly forms dense growth upon invasion. The places of common occurrence of the plant include cultivated lands, fallow 1

2 lands, vacant spaces, plantations, sides of streets, roads, rivers, streams and houses, parks, railway tracks, etc. Its quick encroachment on an area can be attributed to several factors viz. fast growth rate, high reproductive potential, and possession of allochemicals. The invasion of the weed presently affects natural ecological systems, biodiversity, crop production and even human health. It was found that, P. hysterophorus has adverse effects on soil properties too (Kohli and Rani, 1992). In forestry, studies on invasion of P. hysterophurus on forest eco-system are still limited. It has been found to invade forest land areas. A few studies indicate its allelopathic impacts towards forest trees and forest nurseries. Some studies show the allelopathic impact of the weed on multipurpose tree species, like Acacia sp., Casuarina equisetifolia, Eucalyptus sp., Leuceana leucocephala, etc., (Kohli and Rani, 1994). The present study was undertaken with the Objective to study the extent of invasion of P. hysterophorus in chir-pine (P. roxburghii) forests, and the allelopathic effects of this weed on germination rate of chir-seeds. Materials and methods study sites: Solan District Map: not scaling Site 1: Jepla- 72m alt. Site 2: Oachghat 135m alt. Site 3: Kiarighat 175m alt Solan Table 1: Main characteristics of study sites: 2

3 Features Jepla Oachghat Kiarighat Altitude 72 m 135 m 175 m Aspect/position N-E, low part of slope N, high & top parts of site E, high part of slope Soil- texture Sandy- loam, 2% stony Sandy- loam, 3% stony Sandy- loam, 3-4% stony Slope 25 o 3 o 3 o Chir-pine forest/ tree densities Not typical with opencanopy only(2-25) Open & thin canopy densities (2-4 trees/ha) Open and thin canopy densities (2-4 trees/ha) Other remarked features Methods: Highly occupied by Lantan camara, slashed and burnt areas Disturbed by manworks nearby, Parthenium occurred with Bidens. Disturbed by a construction work nearby Surveys on three study areas were done by walk transect with stratified & systematic surveying methods for the inspection of P. hysterophorus invasion into chir-pine forests. Phyto-sociological studies were conducted by applying Quadrat Method (Rastogi, 1999 and Sharma, 23). Quadrats with size of 1m x 1m (for herbaceous species) were laid down for both sites with invasion and without the invasion of the weed (control quadrats), respectively under two canopy levels of chir-forest, which were determined based on number of stems per quadrat of size m x m combined with chart-quadrat method (Sharma, 23); open canopy was recorded with 2-35 stems/ha ( stems/quadrat) and thin canopy with 35-5 stems/ha. Similarly, quadrats with size of 5m x 5m were used for shrubs. In each quadrat, data of number of individual plant, diameters and covers was collected for analyzing quantitative characters of frequency, density, cover area and then analyzing synthetic characters of their relative values of relative density (RD), relative frequency (RF) and relative cover (RC) &. IVI = RD + RF + RC. Table 2: Scale for Measurement of Crown: Scale Value Mid-point of Cover (%) Range of Cover (%) Plant crown covers were done by applying a visual estimate. A suitable scale applied for small plots at study sites is given in table 2. Average cover for a species was estimated by assigning the mid-point of cover to each plot with a given scale value and then averaging the mid-point values for all plots. Plots from which the species was absent were included in the average with a value of zero (Rastogi, 1999). The seedlings were considered as herbs, while saplings as shrubs (Pandey, et al. 22). From the IVI values of each species, species diversity was calculated by using Shannon- Wiener diversity index (H) (Shannon & Wiener, 1963; Verma, 2) and concentration of dominance (Cd) by Simpson s index (Simpson, 1949). s - H= {Ni/N} log 2 {Ni/N} i=1 3

4 Where Ni = Total for the species i th. N = Total Importance Value Index of all the species in site. s - Cd = {Ni/N} 2 i=1 Where Ni and N were the same as those of Shannon- Wiener Information Index. To analyze species dominance and ascertain the resource apportionment among the species at various sites, Dominance- Diversity (D-D) curves were developed. The IVI was used as expressive measure of niche of species, thus treated as an expression of the relative niche size (Pandey, et al., 22). To simulate the field condition that chir-seeds fall on the forest ground which is invaded by P. hysterophorus, and test the allelopathic effect of growing parthenium seedlings on germination of chir-pine seeds, an experiment was conducted in glasshouse. P. hysterophorus seedlings were raised in pots (9x2cm) filled with top soil of chir-forest for 2 weeks to reach the height at 6- cm, then pre-treated chir-seeds were sown on the pots under the conditions; one, two and three seedlings of P. hysterophorus growing per pot were considered as treatments. The germination was observed for 3 days and data recorded. ANOVA single factor in Excel 5. was used for statistically analyzing the data for significance of difference at =.5. Results and discussion Invasion of P. hysterophorus. In Jepla, the existing chir-pine forests were considered as open canopy, other canopies were not available at this altitudinal area. The results in invaded areas showed that P. hysterophorus was highly dominant species with very high IVI (7.1) among 21 herbaceous species found in the site. It was followed by Corchorus olitorius (26.6), Ageratum canyzoides (24.7), Malvastrum tricuspidatum (18.2). The minimum IVI f 3. was noted for Panicum helopus, Adenfum sp. and Bidens pilosa in the invaded sites (table 4). Whereas in control sites (without invasion of P. hysterophorus), maximum IVI was remarked for Corchorus olitorius (31.7) then followed by Imperata cylindrica (3.8), Dicanthium annulatum (25.6). The minimum IVI of 2.3 was belonged to Euphobia geniculata, Euphobia hirta and Solanum khasianum. It was noted that, the location was highly occupied by Lantana camara. There would be no chance for the invasion of P. hysterophorus in to the chir-forest under condition of intact Lantana camara occupation. But the invasion process could start in the site, where the Lantana camara was slashed and burnt by local people. In Oachghat under open canopy of Chir-pine forest, the invasion of P. hysterophorus rerulted in the very high dominance of the species (136.7) among 27 herbaceous species found in the invaded areas. It was followed by Seteria glauca (15.3), Bidens pilosa (15.) and Dicanthium annulatum (14.7). Minimum IVI was noted for Euphorbia geniculata and Euphorbia sp. (1.8). In contrast, the control site of the canopy level was having different pattern of IVI distribution, two native grass species of Chrysopogon montana and Dicanthium annulatum were co-dominant species with IVI of 64.2 & 54.9 respectively. They were 4

5 followed by two species of Triumfetta (17.7 & 17.5). Minimum IVI of 1.9 was noted for three species of Artemisia scoperia, Euphorbia hirta and Verbascum thapsus (table 5). In thin canopy of Chi-pine forest, the invasion of P. hysterophorus was less as compared to that in open canopy with maximum IVI of 83.7, it followed by Chrysopogon montana (51.3) and Dicanthium annulatum (29.2). Species with minimum IVI of 2.1 were Toona ciliata (seedling), Verbascum thapsus and Lespedeza sp. In control site of the thin canopy, the two native grass species of Chrysopogon montana and Dicanthium annulatum were still co-dominant species with maximum IVI of & 4.43 respectively. They were followed by Triumfetta sp. and with IVI of 17.8 and 14.8 respectively. The minimum IVI of 2. in this control site was noted for Artemisia scoperia, Verbascum thapsus and Cassia mimosoides. In Kiarighat, the invasion of P. hysterophorus was found in open-canpy of chir forest only and much less as compared to that in Jepla and Oachghat locations. However the weed was still found to be dominant among 16 herbaceous species in its invasion areas with maximum IVI of It was followed by Dicanthium annulatum (57.2) and Chrysopogon montana (31.7). The minimum IVI of 3. was noted for Ajufa pamiflora. In control site, two native grasses of Dicanthium annulatum and Chrysopogon montana were found to be the highly dominant species with maximum IVI of 94.5 and 6. respectively. They were followed by species coded 2 (26.4) and Lespedeza gerardiana (24.3) (table 7). The total species occurrence found in this area was lesser than that in the Jepla and Oachghat. Regarding the invasion, no found in a specific site/area, it is not meant that it would not happen, but it might be due to the unavailability of its seed and invading factors (Gupta, 1998). This results of high IVI and invasion of P. hysterophorus were same as that of Tiwari & Bisen (1984) reported that its IVI was maximum in the both cropped and un-cropped areas of their study during different seasons. The high IVI of the weed in general is attributed to its competitive ability, Allelopathy and strong adaptive & reproductive potential (Kohli & Rani, 1994). Both competition and allelopathy may be operative simultaneously in some cases and, thus the weed comes out to be the winner. Allelo-chemicals found in the weed were phenolics and sesquitergen lactone parthenin (Batish et al. 23). Germination and growth of Ageratum conyzoides was severely reduced by parthenin (leaf extraction) Singh, et al., (22). Batish, et al. (22) revealed that, germination and growth of both weedy species of Avena fatua and Bidens pilosa was significantly reduced with increasing concentration of parthenin. Species diversity index (H) and concentration of dominance (Cd): Species richness, plant species diversity and concentration of dominance of herbs and shrubs for different sites under two canopy levels of chir-forest and with & without invasion of P. hysterophorus were presented in table 7. For herbaceous species, maximum species richness of 28 was noted for control site under open canopy in Oachghat, then followed by open - control site of Jepla, even this site was noted to be the burnt areas with rather poor ground vegetation per as normal condition. At the same site in Oachghat, the species richness of the herbs under thin canopy showed lower values as compared to that under open canopy. The 5

6 lowest value of species richness for herbs (16) was noted for sites in Kiarighat, even under open canopy of the chir-forest. Regarding shrub species, there was not much difference about the species richness between invaded and control sites. In Jepla, it was noted that, the only Lantana camara was highly dominant species to the site for both kinds of site studied (with and without invasion of parthenium) with IVI of 1.6 & 1., respectively, that could result in low shrub species richness of these sites whereas, in Oachghat and Kiarighat, the species richness of shrubs was higher. It was noted in these sites, there were two or three species, viz., Carissa carandas, Pyrus pashia, Woodifordia floribunda, acting as co-dominant species to their sites. There was significant difference of species diversity between the two kinds of site studied (with and without invasion of parthenium), even for sites, their species richness (SR) were not much different (Oachghat). In these cases, the concentration of dominance (Cd) was taking an important weight in determination of the diversity difference. For herbs, maximum diversity (3.1) was recorded in open-control site of Jepla, whereas, in its site with invasion of the weed, the diversity index was In Kiarighat, although species richness were different between two kinds of the site, but their diversity indices showed almost the same (2.22 & 2.24) due to their Cds were same (.16). In this case, the P. hysterophorus was dominant species to its site, whereas, in control site, the native grass of Dicanthium annalatum was dominating. This was the same condition regarding the dominance. Generally, high concentration of dominance of a site would result less species richness and less species diversity of its ground vegetation. The concentration of dominance was found higher in sites with invasion of P. hysterophorus as compared to those of control sites (without invasion). Higher altitudinal sites showed lesser species diversity when taking the same conditions regarding invasion and canopy levels into consideration. Table 8: Effect of invasion of P. hysterophorus on Species- richness (SR), Shannon-Weiner Diversity (H) and Simpson s indices (Cd) of Herbs and Shrubs at different sites. Sites SR H Cd Canopy Hers Shrubs Hers Shrubs Hers Shrubs P Jepla Open Ctr P Open Ctr Oachghat P Thin Ctr P Kiarighat Open Ctr Note: P. = Parthenium. hysterophorus ; Ctr. = Control Regarding Resource Sharing and Niche Space Apportionment, Dominance Diversity (D-D) curves are drawn to ascertain resource apportionment by the components in the various sites for herbaceous species, wherein the IVI was used as an expressive measure of the Niche of species/ resource apportionment. This is based on the assumption that there is some correspondence between the share of community resource and community space utilized by a species (Whittaker 1975, Pandey 22). Degree of resource apportionment is considered a measure of resource conservation (Pandey 22). 6

7 The D-D curves for herbaceous species under open chir- pine canopy & with invasion of P. hysterophorus in Jepla sites (figure 1a) showed Geometric Distribution Model of Preston (1948), which confirmed niche preemption hypothesis (Whittaker 1975, Pandey 22 ) and indicated low competition among community species, less diversity, maximum utilization of resource due to highly dominating the site and highly occupying space of the weed. Whereas in control site, the D-D curve (figure 1b) showed log-normal distribution model indicating that the site has less number of species in higher IVI range, higher competition, high diversity and efficient utilization of resource (Pandey 22 ). Naturally, the D-D curves for herbaceous species have tendency to approach log-normal distribution model, thus they could play an important role in the resource conservation (Pandey, et al., 22; Verma, 2). But, once invaded/dominated by dominating species like P. hysterophorus, this log-normal distribution model will be broken and changed to geometric distribution model. 7

8 Figure 1 (a & b): Dominance- Divesity curve of herbaceous species in Jepla (Open canopy) Figure 2 (a & b): Dominance- Divesity curve of herbaceous species in Oachghat (Open canopy) D o minance- D iversity curve fo r herb species Open canopy Species sequency (1-21) D o minance- D iversit y curve fo r herb species Open canopy Species sequency (1-27) D o minance- D iversity curve fo r herb species Control Species sequency (1-27) D o minance- D iversity curve fo r herb species Control Species sequency (1-28) Figure 3 (a & b): Dominance- Divesity curve of herbaceous species in Oachghat (Thin canopy) D o minance- D iversity curve fo r herb species 9 8 Thin canopy Species sequency (1-24) D o minance- D iversity curve fo r herb species Control Species sequency (1-26) 8

9 Figure 4 (a & b): Dominance- Divesity curve of herbaceous species in Kiarighat (Open canopy) D o minance- D iversity curve fo r herb species Open canopy Species sequency (1-16) D o minance- D iversity curve fo r herb species Control Species sequency (1-18) In Oachghat under open canopy of chir-pine forest & with invasion of P. hysterophorus, the D-D curve for herbs of the site showed Geometric Distribution Model (figure 2a.), wherein only the weed was highly dominating the site and occupying larger space, occupying the top niche with IVI of and left remaining space for large species for competition. Whereas in control site without the invasion, the top niche of D-D curve was occupied by two native grasses of Chrysopogon montana and Dicanthium annulatum (figure 2b). The curve also showed Geometric Distribution Model with highly dominating of the two grass species. Under thin canopy of chir-pine forest in this location, the D-D curve of site with invasion of P. hysterophorus (figure 3a) showed Geometric Distribution Model, but the dominance of the weed to the site was less, it occupied only 83.7 in top niche space of IVI and it was followed by Chrysopogon montana (51.3) and Dicanthium annulatum (29.2), the two native grasses occupied the intemediate niche space of IVI. The D-D curve of control site in this thin canopy level, however showed rather log-normal distribution model, wherein the two native grasses of Chrysopogon montana and Dicanthium annulatum occupied the top niche space of IVI and became the rather co-dominant species of the site (figure 3b). The D-D curves for herbaceous species under open chir- pine canopy & with invasion of P. hysterophorus in Kiarighat showed rather Geometric Distribution Model (figure 4a), but same as the case of thin canopy in Oachghat site the invasion of the weed was less, it occupied the top niche space with 88.6 of IVI and followed in the middle of the niche by Dicanthium annulatum (57.2) and Chrysopogon montana (31.7), remaining species shared the lower niche. While in its control site, the native grass of Dicanthium annulatum occupied the top niche with IVI of 94.5 and became dominant species of the site. The native grass of Chrysopogon montana and species coded 2 were occupying the intermediate niche. The D-D curve of this site also showed Geometric Distribution Model (figure 4b), Allelopathic effect of P. hysterophorus on germination of chir- seeds 9

10 The experiment was conducted in glasshouse. 9 pots were used for each treatment of the experiment. In each pot of all blocks of experiment both treatment and control, one chir-seed was sown on. Observation of germination rate of the seeds was done for 3 days. The result obtained was as follows: Table: Allelopathic effects of growing seedlings of Parthenium on germination rate of chir-seeds Control Treatment 1: one seedling of P. Treatment 2: two seedling of P. Treatment 3: 3 seedling of P. Seeds germinating/ seeds after 3 days Germination rate (%) Different to control (%) Anova: Single Factor SUMMARY Groups Count Sum Average Variance Control One Seedling Two Seedlings Three Seedlings ANOVA Source of Variation SS df MS F P-value F crit Between Groups E- 9 Within Groups Total Parthenium seedlings in pots show strong allelopathic effects on seed germination in chir pine. One seedling in a pot reduced germination rate down to 17.8% lower than control, while the reduction with 2 seedlings was by 35.6% and with 3 seedlings was by 43.4% (P=.95). Conclusions 1. The invasion of P. hysterophorus has been found in chir-pine forests in all three locations studied. In Oachghat, it has been found to invade into the forest in both open & thin canopy levels of the forest. Main factors governing the invasion of the weed into the chir forest could be the availability of invading material sources, viz. seeds, the disturbance of the forest systems/areas, canopy levels and altitude. 2. The Invasion of Parthenium hysterophorus into the chir-pine forest has significantly affected on the spesies diversity, structure and quality of the ground vegetation. 3. Parthenium seedlings in pots has been found to have strong allelopathic effects to reduce significantly the germination rate of chir pine seeds. Reference: