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Matter dynamics with respect to influences of C<sub>3</sub> and C<sub>4</sub> plants in four subtropical grasslands of Nilgiri Biosphere Reserve, the Western Ghats, India
Matter dynamics with respect to influences of C3 and C4 plants in four subtropical grasslands of Nilgiri Biosphere Reserve, the Western Ghats, India
Journal of Ecology and Environment. 2012. Dec, 35(4): 259-267
Copyright ©2012, The Ecological Society of Korea
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • Received : June 09, 2012
  • Accepted : August 20, 2012
  • Published : December 01, 2012
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About the Authors
Subramanium Paulsamy
Department of Botany, Kongunadu Arts and Science College, Coimbatore 641 029, India
paulsami@yahoo.com
Bong-Soup Kil
Division of Life Science, Wonkwang University, Iksan 570-749, Korea
Munusamy Sivashanmugam
Department of Botany, Kongunadu Arts and Science College, Coimbatore 641 029, India

Abstract
Biomass changes, net primary production and transfer dynamics of dry matter in four subtropical humid montane grasslands at Ebbenadu, Korakundah, Thiashola and Wenlockdown in Nilgiri Biosphere Reserve (NBR), the Western Ghats, India, were investigated. Despite the early report of a higher density and dominance of C 4 species over C 3 species in these grasslands, no functional study of matter production had previously been carried out. Therefore, in order to determine the roles played by these two groups of species, the present study was attempted. The study revealed that the dry matter and net primary production contributed by C 4 species were much greater than those of its C 3 counterpart in all the grasslands. The turnover rate of aboveground dry matter for both C 3 and C 4 species was generally rapid, whereas it was slow for belowground parts, and litter components of C 3 and C 4 species together. In all grasslands, generally about 60% and 10% of the input were channeled to aboveground and belowground parts, respectively, by the C 4 species, whereas the C 3 species transferred only about 22% and 8% of dry matter to aboveground and belowground parts, respectively. The total disappearance of dry matter was 2.73, 2.10, 3.19, and 1.96 g m -2 day -1 in Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands, which was 48.83%, 44.30%, 54.81%, and 41.09% of the total input, respectively, in these grasslands. This resulted in a considerable surplus dry matter production in all the grasslands studied. This balance sheet of dry matter in community function indicates that all the four studied grasslands were supporting the existing wild animals adequately in terms of pasture supply. The study further revealed that the stronger establishment of C 4 species rather than their C 3 counterparts, in terms of higher density and dominance, has driven them to play major roles in matter dynamics and system transfer functions in all the four grasslands studied. This fact evidenced that pasture from C 4 species for wild animals was determined to be higher in comparison to that of C 3 species.
Keywords
INTRODUCTION
Quality and quantity of herbage are important for the successful inhabitation of wild animals, by establishing effective food chains and in turn, these attributes are mainly influenced by species composition and distribution of rainy days in tropical and subtropical regions (Sala et al. 1988, Knapp and Smith 2001, Singh et al. 2005). In addition to these factors, the predominant type of photosynthetic metabolism (C 3 or C 4 or CAM types) which takes place in ecosystems is also reported to play a major role in net primary production (Murphy and Bowman 2007, Niu et al. 2008) Owing to this fact, the analysis of grasslands for primary production contributed by C 3 and C 4 species is essential to assess their production capability. The Nilgiri Biosphere Reserve (NBR) of the Western Ghats is the first established biosphere reserve in India (1986), and covers an area of 5,520 km 2 , harboring many types of vegetation, such as scrub jungles, deciduous forests, wet evergreen forests, shoals (subtropical montane evergreen forests), grasslands etc. (Bor 1938). Among them, the grasslands (1% of geographical area of NBR) provide the major sources of fodder to the rich variety of wild herbivores, like sambar, Nilgiri tahr, spotted deer, great Indian gaur, etc., which in turn support many consumers such as the fox, tiger, panther which are local to the region (Singh 1994). In spite of the higher density and dominance of lower species, the role of C 4 species in community metabolism, with particular reference to primary production and system transfer function (STF), and hence, fodder availability, have not been studied in the grasslands of NBR so far. Hence, in the present study, an attempt has been made to study four major grasslands of NBR to determine the level of primary production and other associated processes of matter dynamics which are dependent on C 3 and C 4 species. This is the first ever attempt to quantify the primary production and fodder status in NBR. The information generated by this study will be used as baseline data for forestry and wildlife planners in the preparation of management plan for grasslands and wildlife.
MATERIALS AND METHODS
- Description of the study area
In NBR, the Western Ghats, India (11°13′ N and 76°39′ E), the grasslands are generally restricted in their distribution to between 2,050 and 2,220 m above m.s.l., and have a geographical area of 4,700 ha. These four major grasslands, situated in the high altitudes of NBR, namely Ebbenadu (265 ha), Korakundah (195 ha), Thiashola (280 ha) and Wenlockdown (480 ha), are classified as southernmontane subtropical wet type (Champion and Seth 1968), and were selected as the representatives of the present study. These four grassland have been selected as representative of the biosphere reservation due to their occupying about 200 ha each, as well as the high degree of species variation contained therein. The rest of the grasslands, numbering around 85, each occupy an area of less than 75 ha.
The climatic data for the study areas are given in Table 1 . The Thiashola and Korakundah grasslands lie adjacent to each other and at more or less same altitude (2,150 m), and hence, the climatic conditions of these two areas are considered to be the same. However, due to the wide spatial separation (15 km) and variation in altitude, the climatic factors vary for other two grasslands, Ebbenadu and Wenlockdown (2,050 and 2,070 m above m.s.l., respectively). The temperature in the study areas varied between 10.4℃ (Korakaundah and Thiashola grasslands during January, 2010) and 24.9℃ (Wenlockdown grassland during May, 2010). The average rainfall of the past 20 years in NBR ranged between 900 mm and 3,000 mm/y. Generally, December to February is the dry season, but unusually, in the month of December 2009 during the study period, adequate rainfall occurred in the high ranges of NBR, including the study areas. Copious rainfall occurs during the south-west (June-September) and north-east (October-November) monsoon seasons. The humidity of the studied grasslands was always high, at around 90%. High velocity wind prevails during the south-west monsoon period in the study areas. The soil is black, loamy, shallow, and acidic.
The perennial grass, Chrysopogon zeylanicus (Ness) Thw. dominates in Ebbenadu and Korakundah grasslands, and two further perennial grasses, Cymbopogon nardus (L.) Rendle and Ischaemum indicum (Houtt.) Merr., were determined to be dominant in Thiashola and Wenlockdown grasslands, respectively. The total number of plant species encountered in the grasslands were 108 in Ebbenadu, 88 in Korakundah, 107 in Thiashola, and 77 in Wenlockdown. In all grasslands the C 3 species contribute more to diversity (61 in Ebbenadu, 52 in Korakundah, 62 in Thiashola and 49 in Wenlockdown). Altogether, the family Poaceae accounted for the highest species contribution, of 22, 20, 31, and 17 species, respectively, in Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands. The other families with generally more than 5 species are Asteraceae, Lamiaceae, Acanthaceae and Rubiaceae. Families such as Caesalpiniaceae, Brassicaceae, Crassulaceae, Piperaceae, Caryophyllaceae, Ranunculaceae and Solanaceae contributed one species each to the respective communities studied. However, including the aforementioned dominant perennial grasses in the respective grassland, the C 4 species exhibited significantly higher density and dominance than C 3 species (Ganesan et al. 2002, Suresh 2008). A rich variety of wild animals, such as Nilgiri tahr, thoda buffalo, panther, sambar, wild boar, block bear, spotted dear, barking dear, Nilgiri lan-
Climatic data of Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands in Nilgiri Biosphere Reserve for the year, 2009-2010TS, Thiashola; KO, Korakundah.Figures in the table are the mean values of the past 20 y.
Lager Image
Climatic data of Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands in Nilgiri Biosphere Reserve for the year, 2009-2010 TS, Thiashola; KO, Korakundah. Figures in the table are the mean values of the past 20 y.
gur, Malabar giant squirrel, wild dog, porcupine, and the palm civet cat etc., are reported to inhabit the study areas (Singh 1994).
Methods
In each grassland, 1ha plot was established to sample the vegetation. The plants available in the experimental plots of the grasslands were identified as being either C 3 and C 4 on the basis of photosynthetic type, by employing iodine tests of the leaves (Bolhar-Nordenkampf 1982). The harvest method (Milner and Hughes 1968) was used for the estimation of biomass and the optimum quadrat size, 50 × 50 cm was obtained through the species-area curve method (Greig-Smith 1964). Ten quadrats were sampled randomly in the study plots of each grassland during the last week of every month from June, 2009 to May, 2010. The quadrats were uniformly positioned in each plot in order to cover the entire area. Harvested samples were sorted, into C 3 and C 4 species and were further separated into aboveground and belowground compartments. However, the litter component was treated as single compartment for both C 3 and C 4 types. For the estimation of belowground biomass, 10 monoliths (50 × 50 × 30 cm) were excavated in the harvested quadrats. The monoliths were soaked in water for few hours and were then washed in water carefully. Since the soil was sandy loam, it was not difficult to separate the roots of C 3 and C 4 plants by this method. The respective biomass values were determined after oven drying the samples at 80°C for 48 h.
The aboveground net primary production (ANP) was determined by summing up positive changes in biomass plus mortality (Billore and Mall 1977). Belowground net primary production (BNP) and litter production were obtained by summation of positive increments of the respective biomass. Net accumulation, transfer and disappearance rates of dry matter were estimated by using the methods of Singh and Yadava (1974) and Sims and Singh (1978).
  • 1) Transfer of live shoots to dead shoots was calculated by the summation of the positive changes in the dead shoots on successive sampling dates
  • 2) Transfer of dead shoots to litter (L) was calculated by summation of negative changes in dead shoots
  • 3) The disappearance of litter (LD) = initial litter biomass + litter production – final litter biomass
  • 4) The disappearance of belowground biomass (BD) = initial belowground biomass + belowground net production – final belowground biomass
  • 5) Total disappearance (TD) = litter disappearance + belowground disappearance
The turnover rate of organic matter was calculated by following the method of Dahlman and Kucera (1965), and the ‘STFs’ were computed by the method of Singh and Yadava (1974). STF is the factor by which the system block multiplies the input to generate the output (Golley 1965) and reflects the orientation of the functioning of an ecosystem in space and time (Sims and Singh 1971).
Grazing by wild herbivores like gaur, sambar, Nilgiri tahr, spotted deer etc. were observed in the study plots. The information collected from the public in near by settlements also confirmed the frequent grazing of these ani-
Lager Image
Aboveground biomass (standing live and standing dead) of C3 and C4 species and total community in four grasslands of Nilgiri Biosphere Reserve, the Western Ghats.
mals in the study areas. However, no data was collected on the quantum of herbage removal by these herbivores through grazing. A population census of these herbivores which graze upon the study areas was also not available. Hence, the results presented in this paper exclude the grazing loss made by wild animals.
RESULTS AND DISCUSSION
Monthly changes in the mass of aboveground dry matter (live and dead shoots) and belowground dry matter of C 3 and C 4 species, and total litter (C 3 + C 4 species) in the four studied grasslands are exhibited in Figs. 1 - 3 . Generally, the aboveground biomass of the C 4 plants are nearly three-fold greater than that of the C 3 counterparts in all four studied grasslands (103-1,238 g/m 2 for C 4 species against 45-463 g/m 2 of the C 3 species ( Fig. 1 ). It is well known that in homogenous communities the species of higher density exert a greater effect on community organization and metabolism (Stout and Brooke 1985). Sivashanmugam (2008) has previously encountered greater number of C 4 species than C 3 species per unit area in all four studied grasslands. La Pierre et al. (2011) reported that the predominance of C 4 grasses may be attributed to the effects of precipitation and temperature during periods relevant to the phenology and growth cycle of these species.
It was further observed that the higher aboveground biomass of both the C 3 and C 4 species was recorded during the monsoon period (June-November) in all the grasslands studied. Ganesan et al. (2002) previously reported the vigorous sprouting of rhizomes of perennials, and the germination of seeds of both annuals and perennials after the advent of monsoon in these grasslands and this response of constituent species could perhaps be the reason for this fact. The aboveground standing dead biomass of C 3 and C 4 species varied between 108 g/m 2 (Wenlockdown) and 468 g/m 2 (Thiashola), and 125 g/m 2 (Wenlockdown) and 1,124 g/m 2 (Thiashola), respectively, with the peak amount occurring during post-monsoon and dry periods (December, 2009-May, 2010). Furthermore, the biomass of this compartment was noted to be inversely proportional to the standing live compartment. This may be attributed to the conversion of the standing live compartment into the standing dead compartment during the dry season, when the vegetative growth of the green shoots is low or almost nil (Singh and Krishnamurthy 1981, Karunaichamy and Paliwal 1994, Paulsamy et al. 2001). In all the grasslands, the standing crop biomass of belowground parts of C 3 and C 4 species varied greatly during the study period ( Fig. 2 ). The C 4 species contributed significantly to belowground dry matter (513-960 g/m 2 ) at all times of sampling, and was greater than that of its C 3 counterpart in all the grasslands studied (167-398 g/m 2 ). The higher density of C 4 species in all grasslands may be accounted for by this fact. In addition, it has been noted that the peak biomass of both C 3 and C 4 species occurred in the month of October, 2009, after the attainment of peak live shoot biomass in September, 2009. Trlica and Singh (1979) and Gupta (1987) explained that this may be due to the transfer of higher amounts of assimilate to roots, wither concomitant with or succeeding the maturity of shoots. The variation in litter biomass of
Lager Image
Belowground biomass of C3 and C4 species, and total community and litter biomass (C3 + C4 species) in four studied grasslands of Nilgiri Biosphere Reserve, the Western Ghats.
C 3 and C 4 species together ranged between 119 and 628 g/m 2 in Thiashola grassland ( Fig. 2 ). In all grasslands, the higher litter mass was estimated during winter, followed by summer months (December through May) because of the transfer from the live shoot compartment due to senescence and mortality of herbage. Therefore, the time of higher belowground dry matter synchronized with the time of higher aboveground standing dead dry matter in the four grasslands studied. Unfavorable climatic conditions, like low and high temperatures in winter and summer months, and relatively low soil moisture during may explain the higher litter mass during this period (Paulsamy et al. 2001).
The ANP estimated were 2,537, 2,400, 2,791, and 2,310 g m -2 y -1 in Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands, respectively ( Table 2 ), and more than 70% of that in every grassland was composed of C 4 species alone. The belowground production ranged between 375 (Korakundah) and 658 g/m 2 (Thiashola) in the studied grasslands ( Table 2 ). The higher performance of C 4 species in terms of net primary production in all the grasslands may be explained due to their significant higher density and dominance over the C 3 counterpart (Sivashanmugam 2008). Ganesan et al. (2002) already reported the dominance of C 4 species in the high level grasslands of NBR. The higher net primary production by C 4 species in the high level grasslands of NBR may also be due to the availability of high intensity light in that region, which is a factor which generally enhances C 4 photosynthetic activity (Chuluun et al. 1999). It is further expected that the energy content in the primary produce of C 4 species may be higher than that of the C 3 species, as the former group assimilated more CO 2 than the later (Osborne and Beerling 2006). This may be due to a reduced loss of energy in the absence of photorespiration in C 4 plants (Holaday and Bowes 1980). The total annual litter production by C 3 and C 4 species together ranged between 350 and 522 g/m 2 ( Table 2 ). This falls well within the reported range of litter production in tropical moist grasslands (Paulsamy et al. 2007, Dhaulakhandi et al. 2010, Melvin et al. 2011).
The turnover rate of dry matter of aboveground parts of both C 3 and C 4 species in the four grasslands was generally rapid (0.99-1.25 g/y) ( Table 2 ). It is well known that humid communities are characterized by a rapid turnover rate of dry matter due to the higher decomposition coefficient (Coupland 1979, Karunaichamy and Paliwal 1994, Paulsamy et al. 2001, Pucheta et al. 2004). On the other hand, the turnover rates of belowground parts of
Annual net production and turnover of dry matter of C3and C4species of aboveground and belowground parts, and litter parts of C3and C4of the four studied grasslands of Nilgiri Biosphere Reserve, the Western Ghats
Lager Image
Annual net production and turnover of dry matter of C3 and C4 species of aboveground and belowground parts, and litter parts of C3 and C4 of the four studied grasslands of Nilgiri Biosphere Reserve, the Western Ghats
C 3 and C 4 species and litter parts (C 3 + C 4 species) were determined to be slow. It may be explained by the fact that most of the constituent species are perennials, and so, they have rhizomes, which are replaced slowly, as the major belowground parts (Senthilkumar et al. 1998).
Table 3 and Fig. 3 showed the data of STFs in the four grasslands studied. Generally, around 60 and 10% of dry matter was channeled to the aboveground and belowground parts of C 4 species, respectively, whereas the C 3 species channeled only around 22% and 8% of dry matter to aboveground and belowground parts in the studied grasslands. The transfer of aboveground production to litter ranged between 15.15% and 18.70%, and the TD from the total net production was determined to exist between 26.6% and 33.72% across the studied grasslands. The transfer of live shoots into the dead compartment, and that of dead shoots into the litter compartment varied between 77.50% (Wenlcockdown) and 83.89% (Thiashola). Thus, there was a net accumulation of 16% to 23% of dry matter in the live shoot compartment alone during the study period of one year. The rates of litter disappearance were 1.19, 1.12, 1.39, and 0.93 g m -2 day -1 and that of the belowground parts were 1.54, 0.94, 1.80, and 1.03 in Ebbenadu, Korakundah, Thiashola, and Wenlockdown grasslands, respectively. The sum of these values gives a TD of 2.73, 2.10, 3.19, and 1.96 g m -2 day -1 , respectively, for these grasslands. These TDs of dry matter were 48.8%, 44.3%, 54.8%, and 41.1% of the total input in Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands, respectively.
Therefore, the net surplus dry matter in all compartments of the studied grasslands was generally above 50% owing to the slower rate of disappearance than that of the accumulation of dry matter. Similar findings have been reported for other humid grasslands in Western Ghats, India (Karunaichamy and Paliwal 1994, Senthilkumar et al. 1998, Paulsamy et al. 2001). It is known that this accumulation of surplus dry matter in these grasslands proves the concept of disclimax stage in the succession of Nilgiri grasslands, as postulated by Bor (1938) and Champion (1939). Furthermore, from a nourishment point of view, it is understood that these grasslands support many wild animals directly or indirectly, by supplying adequate pas-
Lager Image
Diagram depicting net dry matter flow through the various compartments in four humid grasslands of Nilgiri Biosphere Reserve, the Western Ghats. Numbers in boxes are the annual standing crop (g/m2); numbers in circles are total net primary production and disappearance; numbers on the arrow are net flux rates in g m-2 day-1. Ebb, Ebbenadu; Kor, Korakundah; Thi, Thiashola; Wen, Wenlockdown.
Matter dynamics of the four studied grasslands of the Nilgiri Biosphere Reserve, the Western GhatsTNP, total net production; ANP, aboveground net production; BNP, belowground net production; SD, standing dead production; L, litter production; LD, litter disappearance; BD, belowground disappearance; TD, total disappearance.
Lager Image
Matter dynamics of the four studied grasslands of the Nilgiri Biosphere Reserve, the Western Ghats TNP, total net production; ANP, aboveground net production; BNP, belowground net production; SD, standing dead production; L, litter production; LD, litter disappearance; BD, belowground disappearance; TD, total disappearance.
ture throughout the year, by having a huge amount of excess fodder in terms of aboveground matter. In this function, the C 4 species in all grasslands played a pivotal role in comparison with C 3 species. The contribution of over 60% of matter by C 4 species with high energy content is more favorable and supportive for wild animals. By considering these four major grasslands has representatives of pasturelands, it is understood that high altitude grasslands in NBR are more productive and energetic due to the presence of greater numbers of C 4 species. In addition to this factor, the ever availability of water in the streams of the grasslands and safety and shelter of the near by shola forests makes these grasslands an ideal habitats for wild animals in this biosphere reserve. The build-up of dry matter in the grassland community poses a risk of surface fire during the summer months of February-April. Hence, adequate measures have to be taken by the wildlife wardens to prevent the fire and loss of fodder during the lean period. Periodical monitoring of grasslands is an essential part of this process, estimating fodder supply and achieving a higher standard of wildlife management. As it is the first report of primary production status of certain major grasslands in NBR, the data can be used as a baseline to make evaluations and comparisons in future.
Acknowledgements
The authors are thankful to the authorities of the State Forest Department, Government of Tamil Nadu, India, for having given permission and field assistance to carry out the research program.
References
Billore SK , Mall LP 1977 Dry matter structure and its dynamics in Schima grassland community. II. Dry matter dynamics. Trop Ecol 19 29 - 35
Bolhar-Nordenkampf HR 1982 Shoot morphology and leaf anatomy. In: Techniques in Bioproductivity and Photosynthesis (Coombs J, Hall DO, eds). Pergamon Press Oxford 107 - 117
Bor NL 1938 The vegetation of the Nilgiris. Indian For 64 600 - 609
Champion HG 1939 The relative stability of Indian vegetational types. J Indian Bot Soc 18 1 -
Champion HG , Seth SK 1968 A Revised Survey of the Forest Types of India. Government of India Press Nasik
Chuluun T , Tieszen LL , Ojima D 1999 Land use impact on C4plant cover of temperate east Asian grasslands. In: NIES Workshop on Informationon Bases and Modeling for Land-use and Land-cover Changes Studies in East Asia (Otsubo K, ed). Center for Global Environmental Research Tsukuba 103 - 109
Coupland RT 1979 Grassland Ecosystem of the World: Analysis of Grasslands and Their Uses. Cambridge University Press Cambridge
Dahlman RC , Kucera CL 1965 Root productivity and turnover in native prairie. Ecology 46 84 - 89
Dhaulakhandi M , Rajwar GS , Kumar M 2010 Ecological status and impact of disturbance in an alpine pasture of Garhwal Himalaya, India. J Plant Dev 17 127 - 137
Ganesan CM , Arvinth S , Paulsamy S 2002 Strategy to enhance herbage yield in temperate pasture grasslands of Nilgiris. Madras Agric J 89 491 - 498
Golley FB 1965 Structure and function of an old-field Broom sedge community. Ecol Monogr 35 113 - 137
Greig-Smith P 1964 Quantitative Plant Ecology. 2nd ed. Butterworths London
Gupta JN 1987 Ecophysiological association and balance among some grassland communities of Jhansi-India. J Agron Crop Sci 159 293 - 298
Holaday AS , Bowes G 1980 C4acid metabolism and dark CO2fixation in a submersed aquatic macrophyte (Hydrilla verticillata). Plant Physiol 65 331 - 335
Karunaichamy KSTK , Paliwal K 1994 Dry matter production and transfer dynamics in a humid grassland of Western Ghats in Southern India. Trop Ecol 28 17 - 23
Knapp AK , Smith MD 2001 Variation among biomes in temporal dynamics of aboveground primary production. Science 291 481 - 484
La Pierre KJ , Yuan S , Chang CC , Avolio ML , Hallett LM , Schreck T , Smith MD 2011 Explaining temporal variation in above-ground productivity in a mesic grassland: the role of climate and flowering. J Ecol 99 1250 - 1262
Melvin KKK , Japar SB , Ahmed OH , Majid NM , Roland KJH , Silvester J 2011 Litter production, litter decomposition and standing forest litter of rehabilitated forests at Bintulu, Sarawak, Malaysia. Proceedings of the International Symposium on Rehabilitation of Tropical Rainforest Ecosystems Kuala Lumpur 2011 Oct 24-25
Milner C , Hughes RE 1968 Methods for the Measurement ofthe Primary Productivity of Grassland. IBP Hand BookNo. 6. Black Well Scientific Publication Oxford
Murphy BP , Bowman DMJS 2007 Seasonal water availability predicts the relative abundance of C3and C4grasses in Australia. Glob Ecol Biogeogr 16 160 - 169
Niu S , Liu W , Wan S 2008 Different growth responses of C3and C4grasses to seasonal water and nitrogen regimes and competition in a pot experiment. J Exp Bot 59 1431 - 1439
Osborne CP , Beerling DJ 2006 Nature’s green revolution: the remarkable evolutionary rise of C4plants. Philo Trans R Soc Lond B Biol Sci 361 173 - 194
Paulsamy S , Manian S , Udaiyan K , Arumugasamy K , Nagarajan N , Kil BS 2001 Biomass structure and dry matter dynamics in a fire influencing montane subtropical humid grassland, Western Ghats, southern India. Korean J Ecol 24 227 - 232
Paulsamy S , Nisharaj , Senthilkumar P 2007 Litter dynamics in forest ecosystems. J Theor Exp Biol 3 125 - 137
Pucheta E , Bonamici I , Cabido M , D?az S 2004 Below-ground biomass and productivity of a grazed site and a neighbouring ungrazed exclosure in a grassland in central Argentina. Austral Ecol 29 201 - 208
Sala OE , Parton WJ , Joyce LA , Lauenroth WK 1988 Primary production of the Central grassland region of the United States. Ecology 69 40 - 45
Senthilkumar K , Manian S , Udaiyan K , Paulsamy S 1998 Elevated biomass production in burned natural grasslands in southern India. Trop Grassl 32 50 - 63
Sims PL , Singh JS Herbage dynamics and net primary production in certain ungrazed and grazed grasslands in North America. In: Preliminary Analysis of Structure and Function in Grasslands (French NR, ed). Range Science Department Science Series No. 10. Colorado State University Fort Collins, CO 59 - 124
Sims PL , Singh JS 1978 The structure and function of ten western North American grasslands. IV. Compartmental transfers and energy flow within the ecosystem. J Ecol 66 989 - 1009
Singh AN Working Plan for the Nilgiris South Division, 1984-1994. Tamil Nadu Forest Department Coimbatore 1 - 20
Singh JS , Krishnamurthy L 1981 Analysis of structure and function of tropical grassland vegetation of India. Indian Rev Life Sci 1 225 - 270
Singh JS , Yadava PS 1974 Seasonal variation in composition, plant biomass, and net primary productivity of a tropical grassland at Kurukshetra, India. Ecol Monogr 44 351 - 376
Singh SP , Sah P , Tyagi V , Jina BS 2005 Species diversity contributes to productivity: evidence from natural grassland communities of the Himalaya. Curr Sci 89 548 - 552
Sivashanmugam M 2008 Biomass profile, net primary production and bioenergetics as influenced by C3/C4plant composition in four grasslands of Nilgiri Biosphere Reserve, the Western Ghats, India. Bharathiar University Coimbatore, India PhD Dissertation
Stout DG , Brooke B 1985 Quantification of tiller pull-up during grazing of pinegrass. Can J Plant Sci 65 943 - 950
Suresh D 2008 Perpetuation level and regeneration strategies for the poorly established plant species in four grasslands of Nilgiris, the Western Ghats, India. Bharathiar University Coimbatore, India PhD Dissertation
Trlica MJ , Singh JS 1979 Translocation of assimilates and creation, distribution and utilization of reserves. In: Arid Land Ecosystem (Perry RA, Gooddall DW, eds). Cambridge University Press London 537 - 571