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Variation in Soil CO2 Efflux in Pinus Wallichiana and Abies Pindr
Forest Research: Open Access

Forest Research: Open Access
Open Access

ISSN: 2168-9776

+44 1300 500008

Research Article - (2014) Volume 3, Issue 1

Variation in Soil CO2 Efflux in Pinus Wallichiana and Abies Pindrow Temperate Forests of Western Himalayas, India

SM Sundarapandian* and Javid Ahmad Dar
Department of Ecology and Environmental Sciences, School of life Sciences, Pondicherry University, Puducherry, India, E-mail: javiddar29@gmail.com
*Corresponding Author: Professor SM Sundarapandian, Department of Ecology and Environmental Sciences, School of Life Sciences, Pondicherry University, Puducherry-605014, India, Tel: 9443460502 Email:

Abstract

Soil CO2 efflux was measured by alkali absorption method from April to December 2012 in two different forest types, i.e., Pinus wallichiana and Abies pindrow, with three replicate plots in each forest type. Soil CO2 efflux was found maximum in July and minimum in December in both the forest types. Significantly (P<0.001) greater soil CO2 efflux was measured in Pinus wallichiana forest compared to Abies pindrow forest throughout the study period. The range of soil CO2 efflux (mg CO2 m-2 hr-1) from the soil was 126-427 in Abies pindrow forest and 182-646 in Pinus wallichiana forest. Soil CO2 efflux showed greater values in Pinus wallichiana forest than Abies pindrow forest, which could be attributed to greater tree density, tree biomass, shrub density, shrub biomass, forest floor litter and moisture. Soil CO2 efflux also showed significant positive relationship with air temperature. In addition to that the altitudinal difference may be one of the reasons for variation in soil CO2 efflux between the two forest types. This result also indicates that at higher altitude even a small difference in elevation (100 m) alter the functional attributes of the ecosystem.

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Keywords: CO2 efflux; Pinus wallichiana; Abies pindrow; Temperate forests; Western Himalayas

Introduction

Soil CO2 efflux (SR) have received much recent attention from global change and ecosystem science communities for several reasons: (a) Soil CO2 is the second largest carbon (C) flux in terrestrial ecosystems, and plays a critical role in global carbon cycling and (b) Soil CO2 is a key component of biogeochemical models [1], but a large uncertainty exists in integrating respiration components into those models [2,3]. Furthermore, CO2 efflux can vary greatly with vegetation type, soil microbial biomass, and soil chemical properties among and within sites [4,5]. Shifts in vegetation covers may profoundly affect soil CO2 efflux and net primary production by influencing substrate quantity and quality supplied to the soil, fine root, microclimate and structure [6,7]. Approximately 70% of ecosystem respiration in temperate forests is coming from soil [8]. Globally, CO2 efflux is estimated to be 98 ± 12 Pg C yr−1 or 85 Pg C yr−1 if agricultural areas are excluded and is increasing at a rate of 0.1 Pg C yr−1 [9]. Soil respiration is the main form of carbon flux from soil to atmosphere in the global carbon cycle [10]. The CO2 efflux of forest soils has been intensively investigated during the last decade as it represents a major flux of the C cycle in forest ecosystems [11]. Soil properties, such as pH, soil depth, parent material, composition of litter fall and topography may also influence heterotrophic soil CO2 efflux [12,13]. The two important factors for seasonal and inter-annual variability of CO2 effluxare soil temperature and moisture [14-16]. Soil CO2 efflux was also closely related to stand biomass and basal area of trees [17,18].

The variation of soil CO2 efflux among forest types on different spatial scales results from interacting variables such as climatic conditions, forest productivity, litter quality, as well as physical and chemical properties of soils. Another reason for the variation of soil CO2 efflux among different forest sites is possibly the varying contribution of heterotrophic and autotrophic respiration [19]. Underlying processes controlling Soil CO2 efflux are not well known, for example, the coupling and decoupling of Soil CO2 efflux with ecosystem metabolism [20]. Therefore, more data and comprehensive research on Soil CO2 efflux from various biomes are required for assessing and predicting Rs and its responses to undergoing global changes. Quantifying the spatial and temporal patterns of soil respiration and their relations to environmental controls is essential to the C cycle in terrestrial ecosystems [21]. Soil respiration (soil surface CO2 flux, Rs) is mainly composed of heterotrophic respiration (RH) of microorganisms and soil animals, and autotrophic respiration (RA) of plant roots [21,22]. The response and adaptation to environmental variables by RH and RA are different [23,24]. Soil CO2 efflux represents the sum total of all soil metabolic processes in which CO2 is produced [21,25]. The temperate forests play an important role in Indian forestry and ecological construction, where as there is no published information is available on soil respiration from temperate forests of Kashmir Himalayas. Therefore, soil CO2 efflux of forest ecosystems and the controlling factors of CO2 emission in these forests are not only essential to estimate C budget in forest ecosystems in western Himalaya of Jammu & Kashmir (J&K), but also important for evaluating the function of Indian temperate forest ecosystems in global C budgets.

In this study, we measured the soil CO2 efflux in two major temperate forest types i.e., Abies pindrow and Pinus wallichianain Western Himalaya of J&K, Pahalgam, India. The specific objectives were to: (1) compare monthly CO2 efflux between Abies pindrow and Pinus wallichiana forest types and (2) how environmental variables alter soil CO2 efflux between the two forest types.

Materials and Methods

Study sites

The study was conducted in the western Himalaya of Jammu & Kashmir, India (33° 20’ and 34° 54’N latitudes and 73° 55’ and 75° 35’E longitudes and covers an area of 15,948 km2) between the elevations of 2210 and 2375 m.a.s.l. In these two conifer forests: Abies pindrow and Pinus wallichiana, three replicate sub-plots for each forest type were selected (Figure 1). The mean total basal area was 54.1 and 55.3 m-2ha-1 in Abies pindrow and Pinus wallichiana respectively. The dominant shrub and herb species at both the study sites are Vibernum grandiflorum and Stipa sibirica (Table 1).

   (Pinus wallichiana)  (Abies pindrow)
Altitude (m) 2210 2375
Latitude N 34°00’51.9 N 34°02’16.8
Longitude E 075°18’40.6 E 075°20’35.1
Mean annual precipitation (mm) 1289 1289
Dominant tree species Pinus wallichiana Abies pindrow
Density (tree ha-1) 245 ± 16.5 232 ± 12
Tree basal area (m-2 ha-1) 55.38 ± 4.25 54.11 ± 2.63
Shrub density (No. ha-1) 87349 ± 2196 15547 ± 1501
Shrub Biomass (g m-2) 887 ± 590 330 ± 118
Forest floor litter (g m-2)  466.46 ± 15.39  194.13 ± 2.99
Dominant understory species Vibernum grandiflorum
Stipa sibirica
Poa bulbosa
Fragaria nubicula
Vibernum grandiflorum
Stipa sibirica
Fragaria nubicula
Viola odarata
Soil C stock (Mg C ha-1) 0-30 cm 55.38 ± 1.62 50.67 ± 1.20
pH 6.13 ± 0.07 6.13 ± 0.07

Table 1: Characteristics of the Pinus wallichiana and Abies pindrow temperate forest in western Himalayas, India.

forest-research-Abies-pindrow

Figure 1: Map showing the location of the two study sites: site I (Pinus wallichiana) and site II (Abies pindrow).

The annual precipitation during the study period was 1185.8 mm (Figure 2). However, there are differences in the daily weather conditions of Kashmir valley. This is due to high altitudinal differences. Precipitation is bimodal in nature (January-March and August- September). However, the snowfall was heavy in the month of January and February. Average Temperature reaches -8.3°C during winter and 26°C or above during summer [26]. January is the coldest month and June and July is the warmest month.

forest-research-minimum-temperatures

Figure 2: Mean monthly maximum and minimum temperatures and rainfall pattern of the study areas in two temperate forests of western Himalayas, India.

Measurement of total CO2 efflux

Soil CO2 efflux was measured by alkali absorption method [27], at two different forest types, using plastic jars, inserted 10 cm into the ground. Three replicate sub-plots in each forest type were selected for the measurement of soil CO2 efflux. Five replicates of the plastic jars were set up in each sub-plot, and one set of three control plastic jars with airtight lids in each sub-plot. Before each plastic jar was fixed, the vegetation falling within the plastic jar was clipped at the base with the help of scissor. A 50 ml beaker containing 20 ml 0.5 N NaOH was placed in a thin wire tripod stand that holds the jar off the ground by about 2 cm. The alkali was titrated against 1N Hcl after 24 hours of absorption period to avoid diurnal variations [25,28]. The jars were placed randomly, and on each sampling date the soil moisture was measured by gravimetric method up to 10 cm soil depth. The CO2 evolved during the experiment was calculated by following the formula of Joshi et al. [25].

MgCO2 = VxNx22,

Where V represents titration of the blank minus the sample titration and N is the normal acid value.

In the month of October, 15 soil cores up to 30 cm depth were collected randomly in each sub-plot and mixed together to make a composite soil sample. Five representative soil samples from each subplot were taken into the laboratory for further analysis. Soil organic carbon (SOC) was estimated by following the formula of Pearson et al. [29].

Statistical analysis

The variation in soil CO2 efflux in two different forest types (Pinus wallichiana and Abies pindrow) was examined with student‘t’ test. The relationship between soil CO2 efflux with tree density, shrub density, shrub biomass, forest floor litter, and SOC was examined with linear and regression analyses.

Results

Total soil CO2 efflux (mg CO2 m-2hr-1) showed a similar temporal pattern in both the two forest types, the values being highest during the month of July and lowest during the December month (Figure 3). The soil CO2 efflux in the month of January, February and March has not been measured due to complete snow cover. The Pinus wallichiana forest type showed a higher rate of CO2 efflux throughout the study period as compared to Abies pindrow forest type. The mean CO2 efflux (mg CO2 m-2hr-1) values ranged from 126-427 in Abies pindrow forest and 182-646 in Pinus wallichiana forest.

forest-research-Mean-monthly-Soil

Figure 3: Mean monthly Soil CO2 efflux in two different temperate forest types (Abies pindrow & Pinus wallichiana) in western Himalayas, India.

The CO2 efflux showed positive correlation with tree density, shrub density, shrub biomass, forest floor litter, soil organic carbon (SOC) and air temperature (Figure 4a and 4b). However, tree basal area, herb biomass, herb density, rainfall and soil pH showed very weak correlation with soil CO2 efflux.

forest-research-atmospheric-parameters

Figure 4a: Relationship between mean soil CO2 efflux and atmospheric parameters (rainfall and mean temperatures) in temperate forests of western Himalayas, India.

forest-research-temperate-forests

Figure 4b: Relationship between mean soil CO2 efflux with vegetation and soil parameters in temperate forests of western Himalaya, India.

Discussion

In the present study soil CO2 efflux peaked during the warm summer month’s July-August and decreased during the cold winter, December. A similar temporal variation in soil respiration was observed in several temperate forest ecosystems [3,30-33]. In the present study, as the warmer months approached with frequent precipitation, the micro-organisms inhabiting the soil became more active causing an enhanced CO2 efflux rates as observed by Pandey et al. [32]. Similar trend of significant positive correlation of soil CO2 with temperature has been reported by several investigators on temperate forest ecosystems [34,35]. Minimum rate of CO2 efflux from both forest types was recorded in winter months as a result of decreased microbial populations during this period as reported by Pandey et al. [32]. The low solar radiation in winter months may be one of the reasons for lower CO2 efflux rate in winter months [36]. The estimated CO2 efflux ranged from 126-427 in Abies pindrow forest and 182-646 in Pinus wallichiana forest during the present studyis well within the range reported in various temperate forests [3,34,37].

Vegetation may alter soil CO2 efflux rate by influencing soil microclimate and structure, the quantity and quality of detritus supplied to the soil, and overall rate of root respiration [7,38,39]. In the present study, the Pinus wallichiana forest type showed significantly greater (P<0.01) rate of CO2 efflux throughout the study period as compared to Abies pindrow forest type. Similarly the differences in vegetationrelated controls on CO2 efflux have been evaluated for different places for different ecosystems [6,7,36,40,41]. Greater CO2 efflux in Pinus wallichiana site could be attributed to greater tree density, shrub density, shrub biomass, forest floor litter and SOC.

Numerous studies have shown that climatic factors, particularly temperature and precipitation are the major determinants of CO2 efflux at global, regional and local scales [42]. Several studies stated that air temperature have negative relationship with CO2 efflux [43,44]. In the present study soil temperature showed significant positive correlation with CO2 efflux. It is generally acceptable that temperature is a key abiotic variable that controls on soil CO2 efflux. Similar results on the positive correlation between soil CO2 efflux and temperature have been observed by Lloyd and Taylor [45] and Lin et al. [46]. Generally in cold temperate forests, raising air temperature might be creating favourable environment for microbial growth as well as herbaceous community establishment which is reason for increase in CO2 efflux during higher temperature period. Rainfall has also showed weak correlation with soil CO2 efflux which is in accordance with [3,39,47,48].

Carbon stocks in soil and forest floor litter significantly contribute to ecosystem CO2 efflux through manipulating autotrophic and heterotrophic respiration [33,49,50], but these variables are less considered than soil moisture and soil temperature in calculating soil respiration. Zhou et al. [33] stated that combined carbon stock in litter and top soil explain 48% of spatial variation of CO2 efflux in temperate forests. In the present study various parameters such as tree density, shrub density, shrub biomass, forest floor litter and SOC have showed positive correlation with CO2 efflux. The similar results have been shown by other studies [3,33] in temperate forests. The present study revealed that vegetation types and its associated micro-climate determine the rate of soil CO2 efflux.

Acknowledgements

We thankfully acknowledge the financial support provided by UGC, Government of India for its fellowship. Forest Department of Anantnag & Lidder in J&K for permission and Islamaia College of Science and Commerce for laboratory facilities. We appreciate the contribution of anonymous reviewer(s) and the editor for valuable comments on the manuscript.

References

  1. Reichstein M, Rey A, Freibauer A (2003) Modelling temporal and large-scale spatial variability of soil respiration from soil water availability, temperature and vegetation productivity indices. Glo Biogeochem Cycles 17: 1104-1118.
  2. Davidson EA, Janssens IA, Luo YQ (2006) On the variability of respiration in terrestrial ecosystems: moving beyond Q10. Global Change Biology 12: 154-164.
  3. Wang C, Yang J, Zhang Q (2006) Soil respiration in six temperate forests in China. Global Change Biology 12: 2103-2114.
  4. Tang JW, Baldocchi DD (2005) Spatial-temporal variation in soil respiration in an oak-grass savanna ecosystem in California and its partitioning into autotrophic and heterotrophic components. Biogeochemistry 73: 183-207.
  5. Han GX, Zhou GS, Xu ZZ, Yang Y, Liu JL, et al. (2007) Biotic and abiotic factors controlling the spatial and temporal variation of soil respiration in an agricultural ecosystem. Soil Biol Biochem 39: 418-425.
  6. Wang X, Jiang YL, Jia BR, Wang FY, Zhou GS (2010) Comparison of soil respiration among three temperate forests in Chinghai Mountains, China. Canadian Journal of Forest Research 40: 788-795.
  7. Dias AT, van Ruijven J, Berendse F (2010) Plant species richness regulates soil respiration through changes in productivity. Oecologia 163: 805-813.
  8. Law BE, Ryan MG, Anthoni PM (1999) Seasonal and annual respiration of a ponderosa pine ecosystem. Global Change Biology 5: 169-182.
  9. Bond-Lamborty B, Thomson A (2010) Temperature- associated increases in the global soil respiration record. Nature 464: 579-582.
  10. Moriyama A, Yonemura S, Kawashima S, Du M, Tang Y (2013) Environmental indicators for estimating the potential soil respiration rate in alpine zone. Ecological Indicators 32: 245-252.
  11. Schlesinger WH, Andrews JA (2000) Soil respiration and the global carbon cycle. Biogeochemistry 48: 7-20.
  12. De Jong E (1981) Soil aeration affected by slope position and vegetation cover. Soil Sci 131: 34-43.
  13. Tian DL, Yan WD, Fang X, Kang WX, Deng XW, et al. (2009) Influence of thinning on soil CO2 efflux in Chinese fir plantations. Pedosphere 19: 273-280.
  14. Epron D, Farque L, Lucot E, Badot PM (1999) Soil CO2 efflux in a beech forest: dependence on soil temperature and soil water content. Ann For Sci 56: 221-226.
  15. Subke JA, Reichstein M, Tenhunen JD (2003) Explaining temporal variation in soil CO2 efflux in a mature spruce forest in Southern Germany. Soil Biol Biochem 35: 1467-1483.
  16. Wunderland S, Schulz C, Grimmeisen W, Broken W (2012) Carbon fluxes in coniferous and deciduous forest soils. Plant and Soil 357: 355-368.
  17. Epron D, Ngao J, Granier A (2004) Interannual variation of soil respiration in a beech forest ecosystem over a six-year study. Ann For Sci 61: 499-505.
  18. Irvine J, Law BE, Martin JG, Vickers D (2008) Inter-annual variation in soil CO2 efflux and the response of root respiration to climate and canopy gas exchange in mature ponderosa pine. Global Change Biology 14: 2848-2859.
  19. Subke JA, Inglima I, Cotrufo MF (2006) Trends and methodological impacts in soil CO2 efflux partitioning: a meta analytical review. Global Change Biology 12: 921-943.
  20. Ryan MG, Law IS (2005) Interpreting, measuring, and modelling soil respiration. Biogeochemistry 73: 3-27.
  21. Yang J, Wang C (2006) Partitioning soil respiration of temperate forest ecosystems in north eastern China. Acta Ecologica Sinca 26: 1640-1647.
  22. Gower ST, Krankina ON, Olson RJ (2001) Net primary production and carbon allocation patterns of boreal forest ecosystems. Ecological Applications 11: 1395-1411.
  23. Boone RD, Nadelhoffer KJ, Canary JD (1998) Roots exert a strong influence on the temperature sensitivity of soil respiration. Nature 396: 570-572.
  24. Widen B, Majdi H (2001) Soil CO2 efflux and root respiration at three sites in a mixed pine and spruce forest: seasonal and diurnal variation. Canadian Journal of Forest Research 31: 786-796.
  25. Joshi M, Mer GS, Singh SP, Rawat YS (1991) Seasonal pattern of total soil respiration in undisturbed and disturbed ecosystems of Central Himalaya. Biology and Fertility Soils 11: 267-272.
  26. IMD (Indian Meteorological Department, Srinagar) Temperature and rainfall.
  27. Gupta SR, Singh JS (1977) Effect of alkali concentration, volume and absorption area on the measurement of soil respiration in a tropical sward. Pedobiologia 17: 233-239.
  28. Harris DG, van, Bavel GHM (1957) Root respiration in tobacco, cotton, corn and cotton plants. Agron J 49: 182-184.
  29. Pearson T, Walker S, Brown S (2005) Sourcebook for land use, land-use change and forestry Projects. Winrock International 35.
  30. Wu J, Dexin G, Maio W, Tiefan P, Shijie H, Changjie J (2006) Year-round soil and ecosystem respiration in a temperate broad leaved Korean Pine forest. Forest Ecology Management 223: 35-44.
  31. Jina BS, Bohra CPS, Rawat YS, Bhat MD (2008) Seasonal changes in soil respiration of degraded and non- degraded sites in oak and pine forests of central Himalaya. Scientific world 6: 89-93.
  32. Pandey RR, Sharma G, Singh TB, Tripathi SK (2010) Factors influencing soil CO2 efflux in a north eastern Indian oak forest and plantation. Afr J Plant Sci 4: 280-289.
  33. Zhou Z, Zhang Z, Zha T, Luo Z, Zheng J (2013) Predicting soil respiration using carbon stock in roots, litter and soil organic matter in forests of Loess Plateau in China. Soil Biology and Biochemistry 57: 135-143.
  34. Lomoander A, Kattereur T, Anderson O (1998) CO2 evolution from top and subsoil as affected by moisture and constant fluctuating temperature. Soil Biol Biochem 30: 2017-2022.
  35. Laishram ID, Yadava PS, Kakati LN (2002) Soil respiration in a mixed oak forest ecosystem at Shiroy hills, Manipur in North-Eastern India. Int J Ecol Environ Sci 28: 133-137.
  36. Han G, Yu J, Li H, Yang L, Wang G, et al. (2012) Winter soil respiration from different vegetation patches in the yellow river delta, China. Environ Manage 50: 39-49.
  37. Chen GS, Yang YS, Lu PP, Zhang YP, Qian XL (2008) Regional patterns of soil respiration in China’s forests. Acta Ecol Sinica 28: 1748-1761.
  38. Raich JW, Tufekcioglu A (2000) Vegetation and soil respiration: Correlation and controls. Biogeochemistry 48: 71-90.
  39. Lee NY, Koo JW, Noh NJ, Kim J, Son Y (2010) Seasonal variation in soil Co2 efflux in evergreen coniferous and broad-leaved deciduous forests in a cool-temperate forest, central Korea. Ecological Research 25: 609-617.
  40. Zheng ZM, Yu GR, Fu YL, Wang YS, Sun XM, et al. (2009) Temperature sensitivity of soil respiration is affected by prevailing climatic conditions and soil organic carbon content: A trans-China based case study. Soil Biology and Biochemistry 41: 1531-1540.
  41. Yan M, Zhang X, Zhou G, Gong J, You X (2011) Temporal and spatial variation in soil respiration of poplar plantations at different developmental stages in Xinjiang, China. Journal of Arid Environments 75: 51-57.
  42. Sundarapandian SM, Kirthiga J (2011) Soil respiration in different land use systems in Puducherry, India. J Theo Exper. Biology 8: 17-28.
  43. Chen H, Tian HQ (2005) Does a general temperature-dependent Q10 model of soil respiration exists at biome and global scale?. Journal of Integrative Plant Biology 47: 1288-1302.
  44. Rustad LE, Campbell JL, Marion GM, Norby RJ, Mitchell MJ, et al. (2001) A meta-analysis of the response of soil respiration, net nitrogen mineralization, and above-ground plant growth to experimental ecosystem warming. Oecologia 126: 543-562.
  45. Lloyd J, Taylor JA (1994) On the temperature dependence of soil respiration. Functional Ecology 8: 315-323.
  46. Lin G, Ehleringer JR, Rygiewicz PT, Johnson MG, Tingey DT (1999) Elevated CO2 and temperature impacts on different components of soil CO2 efflux in Douglas fir terracosms. Global Change Biology 5: 157-168.
  47. Peng S, Piao S, Wang T, Sun J, Shen Z (2009) Temperature sensitivity of soil respiration in different ecosystems in China. Soil Biology and Biochemistry 41: 1008-1014.
  48. Lee MS, Lee J, Koizumi H (2008) Temporal variation in CO2 efflux from soil and snow surfaces in a Japanese cedar (Cryptomeria japonica) plantation, central Japan. Ecological Research 23: 777-785.
  49. Grogan P, Jonasson S (2005) Temperature and substrate controls on intra-annual variation in ecosystem respiration in two subarctic vegetation types. Global Change Biology 11: 465-475.
  50. Jassal RS, Black TA, Novak MD, Gaumont-Guay D, Ensic Z (2008) Effect of soil of soil water stress on soil respiration and its temperature sensitivity in an 18-year old temperate Douglas-fir stand. Global Change Biology 14: 1-14.
Citation: Sundarapandian SM, Dar JA (2013) Variation in Soil CO2 Efflux in Pinus Wallichiana and Abies Pindrow Temperate Forests of Western Himalayas, India. Forest Res 3:116.

Copyright: © 2013 Sundarapandian SM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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