Understanding the impact of diverse land-use systems (LUS) on soil quality is crucial for sustainable land management practices. This study was conducted in Bengaluru, India, to estimate the soil quality index (SQI) under different LUSs. Twenty-four sampling sites were identified in four different LUSs across the Bangaluru, and soil samples were collected monthly over five months during the Rabi cropping season of 2020-2021. The soil quality assessment involved selecting the minimum data set (MDS) via principal component analysis (PCA) and correlation, scoring soil indicators, and combining these scores to create the soil quality index (SQI). PCA was used to identify key soil properties, which included soil organic carbon (SOC), pH, dehydrogenase, nitrogen (N), and urease, for different LUSs derived from the MDS. The SQI was highest in the horticulture cropping system (0.58), followed by the agro + horticulture cropping system (0.53) and the vegetable cropping system (0.49), and lowest in the pulse cropping system (0.44). These findings emphasize the importance of sustainable land management practices to preserve and boost soil quality across cropping systems.

Inappropriate management of land use systems is one of the main factors that leads to soil quality degradation and its quantification is crucial to their sustainable utilization planning. The objective of the research is to evaluate how various land-use systems, viz., natural forest, tree plantations of Tectona grandis, Terminalia bellirica, Swietenia macrophylla, Artocarpus hirsutus, Melia dubia based agroforestry system, horticulture (Mangifera indica) and agriculture systems impact the soil physicochemical and biological characteristics in semi-arid climatic conditions of India. Principal component analysis followed by linear and non-linear scoring methods was employed to compute the soil quality index (SQI). The soil attributes viz., dehydrogenase activity, acid phosphatase activity, soil available nitrogen, potassium, calcium, porosity, and soil available iron emerged as significant indicators for assessing the soil quality. Among different SQIs, non-linear weighted SQI can efficiently assess soil quality. Based on the non-linear weighted SQI, the order of the systems studied was natural forest (0.973) > Swietenia macrophylla (0.756) > agroforestry (0.737) > agriculture (0.556) > Tectona grandis (0.416) > Terminalia bellirica (0.373) > Artocarpus hirsutus (0.343) > Mangifera indica (0.208). The study concludes that converting natural forests into different land-use systems deteriorated the soil quality. Identifying soil indicators will help rapidly diagnose soil degradation, assess soil-based ecosystem services, and design appropriate land management practices in the future.

Understanding the impact of urbanization on soil quality is crucial for sustainable land management practices. This study was conducted in Bengaluru, India, to estimate the soil quality index (SQI) under different rural‒urban gradient (RUG) zones. Twenty-four sampling sites were identified along the RUG, and soil samples were collected monthly over five months during the October to February of 2020-2021. The soil quality assessment involved selecting the minimum data set (MDS) via principal component analysis (PCA) and correlation, scoring soil indicators, and combining these scores to create the soil quality index (SQI). PCA was used to identify key soil properties, which included microbial biomass carbon (MBC), SOC, N, manganese (Mn), and urease for different RUG zones derived from the MDS. The rural zones had the highest SQI (0.57), followed by the peri-urban (0.47 and 0.48) and urban (0.45 and 0.47) zones. These findings emphasize the importance of sustainable land management practices to preserve and boost soil quality across diverse regions, particularly in the face of rapid urbanization and industrialization.

The study focused on the composition of soil mesofauna within changing cropping systems influenced by urbanization in Bengaluru, Karnataka, India during the rabi season of 2020 (October)–2021 (February). Four major cropping systems, namely pulses (red gram), vegetables (tomato and ridge gourd), horticulture (grapes and chickoo), and agriculture + horticulture crops, (coconut + fodder plantation), were examined across urban, peri-urban, and rural zones in Bengaluru. The research uncovered a total of 714 individuals belonging to 16 different soil mesofauna taxa among the crops studied. Collembolans were found to be the most abundant members of the mesofauna community, with mites following closely. In terms of population dynamics, the highest mesofauna population was observed in December 2020, totaling 248 individuals, while the lowest count was recorded in February 2021, with 104 individuals. Among the crops studied, the highest number of individuals was found in Horticulture systems, with 277 individuals, closely followed by the Agri + horticulture cropping system, which had 158 individuals. When considering the geographical zones, the highest number of individuals was recorded in the urban zones, with 270 individuals, followed by peri-urban areas with 229 individuals, and the rural zone had the lowest count, totaling 225 individuals. From the results, less disturbed soil environment in horticulture cropping system, post-monsoon conditions in December (2020), and the urban heat in urban zone appeared to favor the proliferation of soil mesofauna.

Photosynthesis is the only natural process that converts photon energy into chemical energy, and it is responsible for 90–95% of plant biomass accumulation and hence growth. Environmental factors such as light, temperature, and CO2 concentration in the atmosphere are major factors that influence photosynthesis, and excess of these can cause stress on plants. The photosynthetic response of tree species is found to vary to these factors. Therefore, the photosynthetic response of tree species can be a good indicator to assess these environmental factors that are changing due to urbanization and can be used to mitigate these factors as well by cultivating suitable tree species. The present study provides information on the seasonal variations in photosynthetic activity in six tree species. In the present study during the month of May (late summer to early monsoon) most of the tree species showed higher photosynthetic rates. It is also noticed that transpiration rate and water use efficiency was more in the month of May compared to other months. An increase in net photosynthesis and transpiration is observed among the tree species under high rainfall conditions 285.2 mm. It is also observed that photosynthesis decreased where the evaporative demand is very high.

Identifying plant traits that are critical in carbon assimilation under field conditions will reflect the performance and hence could be useful tool for assessing field performance under semiarid conditions. This hypothesis was tested using forty-two Melia dubia germplasm lines grown for four years under rainfed conditions. Cumulative increment in girth over years (CAI) and within a year (MAI) was the indication of growth which varied from 2.67 to 9.25 cm year(-1) and 1.09 to 0.17 cm month(-1), respectively across forty-two germplasm lines, suggesting wide variations in growth and growth rates. Eight established plant traits that regulate photosynthesis process under moisture stress conditions were evaluated. Four out of eight traits studied emerged as most critical plant traits. They were leaf area, leaf area index, specific leaf area and cumulative carbon assimilation rate (Delta C-13). Strong positive linear relationships and percent contribution of these traits with growth suggested the usefulness of these traits in field evaluations of Melia dubia plant since these traits could easily be monitored at any stage of tree growth.

Cation exchange capacity (CEC) of host is a well-recognized criterion to establish the suitable hosts for sandalwood. An experiment for nine months was laid down to find suitableprimary hosts on the basis of CEC of host root, morphology, host use efficiency (HUE) and biomass of sandalwood at seedling stage in the nursery of Institute of Wood Science and Technology, Malleshwaram, Bengaluru, with 10 treatments (different hosts including control), 3 replications in Complete Randomized Design (CRD). Based on preliminary data, increased and decreased CEC values of host roots were categorized as A and B, respectively. Results indicated that after being parasitized, decreased CEC of host root (category B) possibly increased the HUE of sandalwood seedlings consequently, increased its biomass in comparison to hosts belonged to category A (increased CEC) in nursery condition. Among these treatments, T4 ( Santalum album + Alternanthera ficoidea ), T5 ( Santalum album + Aerva sanguinolenta ) and T8 ( Santalum album + Mentha arvensis L.) were good primary hosts for sandalwood seedlings belonged to category B. This indicated that hosts with decreased root CEC may not always poor as reported previously. The observations also validated the fact that primary hosts are necessary for sandalwood seedlings at early nursery stage to achieve better growth.

This study is an attempt to evaluate six tree species with potential for growth and water use efficiency under 50% moisture stress, based on the carbon assimilation capacity in order to identify species to be grown in low moisture conditions. Plants were maintained at field capacity (control) and at 50% less than the field capacity (stress) in lysimeters for 90 days by weighing them and replenishing with the water lost. Eucalyptus comaldulensis and Melia dubia recorded 259 and 204 and 243 and 151 g plant−1 of biomass under control and moisture stress conditions respectively while Simaruba glauca and Callophylum inophyllum recorded 61–53 and 37–23 g plant−1. Photosynthetic rates of these species were in the range of 25.43–22.78 and 9.10–8.03 μmol m−2s−1 under control and stress conditions respectively, which corroborated with biomass production. Both diffusive and carboxylation processes of photosynthesis were higher in species with higher biomass. Photosynthetic rates assessed using leaf model and cumulative models go with each other. Species with higher photosynthetic rates tended to sustain under stress by reducing photosynthetic surface area and maintain the growth rates suggesting that growth performance under moisture stress depends on carbon assimilation capabilities. This was also evident in species with low photosynthetic rates which recorded lower growth rates. Species with lower carbon assimilation showed higher water use efficiency, while it was the opposite in species with higher carbon assimilation. Isohydric behavior of stomata help plants to maintain longer stomatal conductance and hence the photosynthetic rates, but lower water use efficiency. Such a strategy helps plants in sustaining growth under intermittent moisture stress. Thus slow growing species with higher water use efficiency and lower moisture consumption are useful in establishing tree cover in marginal lands with low moisture.

Urbanization and its consequences on water quality is one of the important crises that need immediate attention. It has come to a stage of utilizing all available water resources and therefore it is a matter of level of contamination and the purpose. This study is an attempt to see the water quality in the agro-ecosystems along rural urban transition zones (RUT) of Bengaluru in terms of the suitability of water for major utilities such as drinking purpose, irrigation and for livestock use. Water quality is determined based on specific physical, chemical and biological surrogates in ground water bodies (n=30) located in agriculture lands. The mean water quality index of urban ground water suggest that it is not suitable for drinking but, fairly suitable for irrigation and industrial use (C3 and C4 category), while in the transition and rural area it is again not suitable for drinking purpose but suitable for irrigation and industrial use (C2 category). Piper tri-linear diagram indicate that majority of the ground water samples belong to mixed Ca2+–Mg2+– Cl−–SO24− type and continuous use of this water leads to soil degradation and crop damage in agroecosystems. Results indicate that water quality in the RUT is depilating and cannot be used for human consummations. Hence there is an immediate need to put water resource management in place.

Water contamination is one of the many consequential concerns of urbanisation that need immediate attention in most cosmopolitan cities. In Bengaluru, one of the fast growing metropolitan cities in India, most of the water bodies are contaminated. Thus it is critical to ascertain the extent of as well the source of contamination. This study is an attempt to see the water quality in the agro-ecosystems along rural urban transition zones (RUT) of Bengaluru. Water quality is determined based on specific physical, chemical and biological surrogates in both surface water (n=30) bodies located within one kilometer radius of agriculture lands. The mean water quality index of urban surface water suggest that it is not suitable for drinking but, fairly suitable for irrigation and industrial use (C3 and C4 category), while in the transition and rural area it is again not suitable for drinking purpose but suitable for irrigation and industrial use (C2 category). Piper tri-linear diagram indicate that majority of the surface water samples belong to mixed Ca2+–Mg2+– Cl−–SO24− type. Results indicate that water quality in the RUT is depilating and cannot be used for human consummations. Hence there is an immediate need to put water resource management in place.

The present assess the green house gas (GHG) emission from cultivation over the past 50 years in India. Emission has increased by 161% over 50 years from 14.81 TgCE/year (0.12 tCE ha−1yr−1) in 1960 to 38.71 TgCE/year (0.28 tCE ha−1yr−1) by 2010. This is due to increase in the use of inputs primarily; chemical nitrogen fertilizer, shifting from conventional animal and human energy sources to carbon-intensive diesel and electricity-dependent machineries. It is also due to 16% decrease in area of less carbon-intensive coarse cereals and 22% increase in rice cultivation. Among crops, rice recorded maximum emission (23.75 Tg CE/ha) while it was lowest in redgram (2.98 Tg CE/ha). Nitrogen among inputs, accounted for 92 and 83% emission between 1960 and 2010 respectively while, nitrogen use efficiency declined, suggesting loss of added nitrogen to atmosphere as N2O. Methane accounted for 90 and 58% of emission over 1960 and 2010, respectively, indicating a declining trend over the years. Thus, amending nitrogen fertilizer use and measures to reduce methane emission alone can substantially reduce the carbon footprint of the crop cultivation process. There is also ample scope for reducing emissions from energy sources.

Among the various abiotic stress, water deficit is the most devastating factor. The present investigation was carried out to identify desirable genotypes under low rainfall conditions. Forty-two genotypes of Melia dubia were evaluated for different growth parameters like girth, mean annual girth increment, plant height, total standing biomass per tree, leaf area, fibre qualities like fibre length and fibre diameter at the Hoskote Research Station of Hoskote Range Forest Division, Bengaluru Rural District, Karnataka. Significant differences were observed for all the growth parameters among the germplasm lines. In experiment I, germplasm line MD013 showed highest girth (35.81 cm), plant height (3.83 m2), biomass (17.26 kg/tree), leaf area (3.21 cm2), fibre length (886.67 im) and fibre diameter (33.30 im) while in experiment II, germplasm line MD058 accounted for the maximum girth (37.40 cm), plant height (3.83 m), biomass (16.76 kg/tree), leaf area (3.05 cm), fibre length (903.33 im) and fibre diameter (39.37 im). MD058 in experiment I and MD013 in experiment II exhibited significant growth performance to other germplasm lines. These lines were found suitable for cultivation in the low rainfall regions.

The community conserved sacred groves which exist over generations, is a testimony for positive anthropogenic intervention in biodiversity conservation.Groves existing across diverse climatic conditions of Central Western Ghats has recorded144 tree species of which 15 were endemic in nature with a high Shanon's diversity index of 4.15.High tree density (360 trees ha -1 ) with a basal area of 32.8-49m 2 ha -1 is an indication of favorable growing conditions as well as efficient functioning of the groves.This was further substantiated from the typical inverted "J" curve of girth class distribution, indicating the normal regeneration process prevailing in the groves.The carbon sequestered from above ground biomass of standing trees, soil organic carbon and litter was 139.78, 62.3 and 0.38 tC ha -1 respectively.About 196.43 tCha -1 sequestered in the groves is highest so far reported among the forest ecosystems of India.Thus results indicate the importance of community conserved forest ecosystems in sustaining the biodiversity which impart functional diversity and in turn resilience of the ecosystem.Such self sustaining ecosystems under changing climatic conditions are most essential in mitigating climate change.

Agriculture is one of the major sectors that get affected as well as cause climate change. Arid and semiarid regions of the world are expected to become more vulnerable to climate change. Thus, in order to develop appropriate mitigation or adaptive strategies, carbon footprint analysis of agriculture sector becomes crucial. Emissions resulting from the cultivation process depend on the inputs used and the environmental conditions. The present study is an effort to analyze the carbon footprint of agriculture crops cultivated in the state of Karnataka with 80% land under rainfed agriculture under semiarid tropical conditions. About 5.37 terra grams of carbon equivalent (TgCE) was found to occur annually. Cereals contributed 5.04 TgCE/year of which 78% comes from rice, as it emits methane in addition to CO 2 and NO 2 . Possible approaches to reduce methane emission are discussed including the possibility of replacing the area under rice with other crops without affecting the dietary as well as peoples preferences. Inorganic nitrogen fertilizer use in the cultivation process accounts for 72% of the total emissions. Combining pulse crops effectively in conventional practices of crop rotation and mixed cropping systems can help in reducing emissions. Manual agriculture followed due to small land holdings facilitates low energy use (8%) under rainfed agriculture, resulting in low carbon input. Irrigated agriculture recorded 4.19 TgCE/year which is almost 3.5 times more than the rainfed agriculture practice. Among the two cropping seasons, Kharif season which is the major cropping season recorded 3.85 TgCE/year against 1.52 TgCE/year during Rabi season. Most tropical regions with fragmented land, low carbon emission as well as with the low productivity need to be treated differently.

Dendroclimatology can be a useful tool in assessing moisture stress tolerance in tree species that form distinct annual rings, especially in natural selection.

Remote sensing and GIS based approach was used for estimation of above ground biomass (AGB) and carbon pool at regional scale in south western part of Karnataka. Present study integrates field measured biomass with spectral responses of different bands and indices of MODIS 250 m spatial resolution. Based on relative forest area within the MODIS pixel, area weighted biomass was estimated for each site using ground measured plot (0.4 ha) biomass. Field measured AGB ranged between 7.25 to 287.047 t-dry wt ha(-1) across different vegetation types in the region. The best fit regression equation (Y = 0.053e(9.382x)) was obtained between area weighted AGB (Y) and NDVI of December month (x) with R-2 value of 0.8074. This equation was further used for spectral modeling to estimate the AGB and vegetation carbon pool and to Prepare a map to understand the geospatial distribution in the region. Total AGB on dry weight basis was estimated at 6.43 Mt (mean biomass density of 70 t ha(-1)) and carbon stock of 3 Mt (mean carbon density of 33 t ha(-1)) in the entire region. The present study revealed that remote sensing technique combined with field sampling provides quick and reliable estimates of above ground biomass and carbon pool and such approach could be used more conveniently for carbon inventories at the State and National level.

Use of biomass as substitute for fossil fuel and high energy intensive products like cement, steel, etc. has significant contribution in overcoming global climate change. This not only ensures the reduction of CO 2 emission to the atmosphere but also encourages the absorption of CO 2 from the atmosphere by the trees replaced after harvest. In the present study, the authors estimated the quantity of wood removed from private plantations of Kodagu district dominated by Coffee plants ( Coffeea canefora and Coffeea arabica ), for a period of 12 years (1992 to 2003). From the study it is found that, 1,35,794 Mt of wood was harvested including fuelwood and other forms of wood. Out of this 57,474 Mt was used for manufacturing various utility products which will sequester 1,05,379 Mt of CO 2 for period ranging from 60 to 200 years. A total of 78321 Mt of the harvested wood was used for fuel 3 purpose which, in energy density terms, is equivalent to 25,580 Mt of LPG and 27,285 X 10 3 liters of kerosene.