Seasonal variations in species diversity, dry matter and net primary productivity of herb layer of Quercus leucotrichophora-Pinus roxburghii mixed forest in Kumaun Himalaya, India

2011 ◽  
Vol 23 (2) ◽  
pp. 223-228 ◽  
Author(s):  
Mukesh Joshi ◽  
Y. S. Rawat ◽  
J. Ram
Author(s):  
S. K. Goroshi ◽  
R. P. Singh ◽  
R. Pradhan ◽  
J. S. Parihar

Polar orbiting satellites (MODIS and SPOT) have been commonly used to measure terrestrial Net Primary Productivity (NPP) at regional/global scale. Charge Coupled Device (CCD) instrument on geostationary INSAT-3A platform provides a unique opportunity for continuous monitoring of ecosystem pattern and process study. An <i>improved</i> Carnegie-Ames-Stanford Approach (<i>i</i>CASA) model is one of the most expedient and precise ecosystem models to estimate terrestrial NPP. In this paper, an assessment of terrestrial NPP over India was carried out using the iCASA ecosystem model based on the INSAT CCD derived Normalized Difference Vegetation Index (NDVI) with multisource meteorological data for the year 2009. NPP estimated from the INSAT CCD followed the characteristic growth profile of most of the vegetation types in the country. NPP attained maximum during August and September, while minimum in April. Annual NPP for different vegetation types varied from 1104.55 gC m<sup>&minus;2</sup> year<sup>&minus;1</sup> (evergreen broadleaf forest) to 231.9 gC m<sup>&minus;2</sup> year<sup>&minus;1</sup> (grassland) with an average NPP of 590 gC m<sup>&minus;2</sup> year<sup>&minus;1</sup>. We estimated 1.9 PgC of net carbon fixation over Indian landmass in 2009. Biome level comparison between INSAT derived NPP and MODIS NPP indicated a good agreement with the Willmott’s index of agreement (d) ranging from 0.61 (Mixed forest) to 0.99 (Open Shrubland). Our findings are consistent with the earlier NPP studies in India and indicate that INSAT derived NPP has the capability to detect spatial and temporal variability of terrestrial NPP over a wide range of terrestrial ecosystems in India. Thus INSAT-3A data can be used as one of the potential satellite data source for accurate biome level carbon estimation in India.


Author(s):  
G. Rodigheri ◽  
D. C. Fontana ◽  
L. P. Schaparini ◽  
G. A. Dalmago ◽  
J. Schirmbeck

Abstract. Net Primary Productivity (NPP) is an important indicator of vegetation growth status and ecosystems health. NPP can be estimated through remote sensing data, using vegetation indices such as NDVI. However, this index may show systematic differences when using several orbital sensors. Therefore, the objective of this paper was to compare the NDVI data obtained from different sensors and evaluate the impact over the soybean biomass and NPP estimates. NDVI data were recorded from 4 sensors, one on the field and others 3 orbitals sensors (Landsat 8/OLI, Sentinel 2/MSI and Terra/MODIS). Measured data on the field, Photosynthetically Active Radiation (PAR) and Dry Matter (DM), were used to modeling the total DM and also NPP. The NDVI data from different sensors showed differences throughout the cycle, but compared to the reference data there was a correlation greater than 0.84. The DM presented a correlation of 0.91 with the field measured MS data while the NPP presented differences of up to 240 gC/m2/month from in relation to the reference data. Therefore, NDVI obtained from multiple sensors can be used to estimate NPP for surface analysis. However, for more consistent evaluations, a function of adjustment between the NDVI sensor data and NDVI reference data is required, so that the NPP estimation be better correlated to the actual data.


2021 ◽  
Vol 12 (1-2) ◽  
Author(s):  
Harish Bharti

ABSTRACT The forests of Karsog Forest Division in Himachal Pradesh were temporally analyzed for change in tree species composition. These are based on the species composition in different communities and variations along the different altitudinal gradients. The enumeration records were procured from the forest department. Total 143 forest compartments were analyzed to study the change in tree species in thirteen delineated communities, out of which six were pure forest communities and seven were mixed forest communities. The change in density (Ind/ ha) in tree species was calculated between two enumeration years, that is 1986and 2013. Results showed that out of thirteen communities, only three pure communities viz., Pinus roxburghii, Abies pindrow and Quercus leucotrichophora showed increased density while other pure communities showed decreased density in two enumeration years. Altitudinal based study revealed that the lowest altitudinal gradient (1000-2000 m) showed increase in tree density while in 2000-3000 m zone a gradual fall in tree density was observed temporally.


2021 ◽  
Vol 21 (No 1) ◽  
Author(s):  
Sonam Sharma ◽  
V.K. Yadav

The primary productivity of the Mahil pond has been estimated from March 2017 to February 2018 at four different stations. Various physicochemical parameters and phytoplankton were studied. The seasonal variation of primary productivity revealed that maximum and minimum values of Gross primary productivity and community respiration were associated with rainy and summer seasons respectively. The minimum values of Net primary productivity were recorded during rainy season and maximum during winterfor different study stations.


2021 ◽  
Vol 16 (1) ◽  
pp. 151-157
Author(s):  
Amit Mittal ◽  
Ashish Tewari ◽  
Nandan Singh ◽  
Somesh Sharma

Phenology is one of the simplest and most effective study to understanding the role of climate change in recent scenario. A number of biotic and abiotic drivers controlled the timing and duration of various phenophases in same or different species. Temperature, rainfall and photoperiod are key drivers which adversely affect the phenology of woody plant. The study sites were conductedat 413 and 2345m elevation in Nainital forest division of Kumaun Himalaya. The phenological study were carried out onShores robusta, Mallotus philippinensis, Pinus roxburghii, Myrica esculenta,Quercus leucotrichophora and Rhododendron arboreum. The phenological observations were made at 15 days interval for low activity period and weekly in the periods of high activity. Phenological records were made for four phenophases, viz., leafing, leaf drop, flowering and seed fall.The leaf fall in S. robusta started from March 2nd week and was complete by the end of April. In M. philippinensis the fruiting commenced from the beginning of December and seed fall was complete by the 3rd week of April. In M. esculenta male flowers appear from August end and flowering was complete by October end.In R. arboreum seed dispersal started from February end and all the capsules had opened by mid-March. It is apparent from the present study that the phenological events of species controlled/shifted due to climatic irregularities and temperaturerise and these phenomena showed worldwide. Microclimatic condition alsoresponsible for controlling/shifting the phenological patterns of same or different species.


2021 ◽  
Vol 9 ◽  
Author(s):  
Tarun K. Thakur ◽  
Digvesh K. Patel ◽  
Anita Thakur ◽  
Anirudh Kumar ◽  
Arvind Bijalwan ◽  
...  

In recent decades, degradation and loss of the world’s forest ecosystems have been key contributors to biodiversity loss and future climate change. This article analyzes plant diversity, biomass, carbon sequestration potential (CSP), and the net primary productivity (NPP) of four vegetation types viz., Dense mixed forest (DMF); Open mixed forest (OMF); Teak plantation (TP), and Sal mixed forest (SMF) in the dry tropical forest ecosystem of central India through remote sensing techniques together with physical ground observations during 2013–2018. The total C storage in trees varied from 16.02 to 47.15 Mg ha−1 in studied vegetation types with the highest in DMF and lowest in OMF. The total C storage in stem wood, branches, and foliage falls in the range of 52.93–78.30%, 9.49–22.99%, and 3.31–12.89% respectively. The total standing biomass varied from 83.77 to 111.21 Mg ha−1 and these variations are due to different vegetation types, with the highest in DMF followed by TP, SMF while the lowest was estimated in OMF. The net primary productivity (NPP) [aboveground (AG) + belowground (BG)] varied from 7.61 to 9.94 Mg ha−1 yr−1 with mean values of 8.74 Mg ha−1 yr−1 where AG shares a maximum contribution of 77.66%. The total biomass production was distributed from 64.09 to 82.91% in AG and 17.08–35.91% in BG components. The present study outlines that the studied forest ecosystem has the substantial potential of carbon sequestration and a great possibility of mitigating local and global climate change.


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