A water quality index provides a single number that expresses overall water quality at a certain location and time based on several water quality parameters. Water quality index (WQI) is valuable and unique rating to depict the overall water quality status in a single term that is helpful for the selection of appropriate treatment technique to meet the concerned issues. These indices utilize various physico-chemical and biological parameters and have been resulted as an outcome of efforts and research and development carried out by diff erent government agencies and experts in this area globally. This review paper includes the water quality assessment with water quality indices being used globally.

Litter plays a vital role in forest ecosystems, significantly contributing to nutrient cycling through litter production and decomposition. Understanding these processes is crucial for forest management and conservation, especially in the face of global environmental changes. This research is important because it provides insights into the litterfall patterns and nutrient dynamics of different tree species, which are essential for maintaining forest health and productivity. The present study aimed to determine the quantity and pattern of litterfall and nutrient return to the forest floor of Pinus roxburghii, Shorea robusta, and Bambusa tulda. We collected litterfall monthly over two years in three different plantations of P. roxburghii, S. robusta, and B. tulda, and measured the nutrient content of the litter. The mean annual litter production recorded in these plantations was greatest in B. tulda (4652.15 kg ha-1yr-1), followed by S. robusta (3731.4 kg ha-1yr-1) and P. roxburghii (2588.85 kg ha-1yr-1). The plantations included both the main species and associated understory vegetation, such as herbs and shrubs. Leaf litter from the main species accounted for the highest total litterfall in April. During this period, leaf litter accounted for approximately 24% of the total in S. robusta, 16% in P. roxburghii, and 15% in B. tulda. Minimum mean monthly litterfall was recorded in September and November for P. roxburghii and S. robusta, and in November and December for B. tulda. There was significant monthly variation in nutrient content between the species. Maximum nitrogen (N) was measured during June for P. roxburghii, December for S. robusta, and January for B. tulda, and phosphorus (P) and potassium (K) concentrations also varied significantly. Annual patterns of nutrient return followed the order N > K > P. Maximum nutrient return was observed during April in all species due to higher litter production during that month. There was greater variability in litter quality in the broadleaved forest (S. robusta) than in the coniferous forest (P. roxburghii), indicating the more dynamic functioning of broad-leaved plantations compared to coniferous ones.. This research highlights the critical role of litterfall in nutrient cycling within forest ecosystems and underscores the importance of considering species-specific litter dynamics in forest management and conservation strategies.

Agroforestry has been recognized by the Intergovernmental Panel on Climate Change (IPCC) as important for reducing soil erosion and carbon sequestration. The Indian Eastern Himalayan region is very diverse in terms of agroforestry systems varying in species composition and management practices according to agro-climatic zones as well as inherent traditional knowledge of the practising communities. This land use system forms an important part of the traditional agricultural practices of Indigenous communities of this region by supporting their livelihood and also deeply embedded in their socio-cultural traditions. The present review is an attempt to appraise the different agroforestry systems of the eastern Himalayan region of India, with a particular focus on their role in carbon sequestration and the provision of ecosystem services. Analysis of the literature revealed the multifarious types of ecosystem services that can be derived from this land use system ranging from provisioning, regulating and cultural services. Moreover, the potential for carbon sequestration was reported by several researchers and was found to vary concerning species composition and type of management. Despite its importance, agroforestry systems also face several challenges due to various factors including lack of quality planting material, market linkages, knowledge gap, and policy complications as well as the impacts of climate change. In conclusion, we highlighted several opportunities for sustainable agroforestry practices by promoting them as biodiversity conservation models, encouraging participation of agroforestry practitioners in carbon credit markets, linking farmers with agricultural extension services and integrating communities’ traditional knowledge with scientific innovation for improved seed, effective soil and water management, and sustainable harvesting, value addition and marketing of agroforestry products.

The present study focused on phyto-sociological and physico-chemical attributes of soil in Pinus roxburghii (Chir pine) and Shorea robusta (Sal) plantations in a reserved estate of New Forest, Dehradun. A total of 33 plant species comprising of 18 trees, 10 shrubs and five herbs were recorded from the study area. The tree density, in chir pine was lower 950 individuals/ ha as compared to 1073 individuals/ ha in sal vegetation. In saplings, high density was observed for Syzygium cumini (20 individuals/ 100m2) in sal followed by Broussonetia papyrifera (19 individuals/100m2) in chir pine plantation. Lantana camara, marked its presence with highest density (49 individuals/100 m2) in chir pine followed by Clerodendrum infortunatum (18 individuals/100 m2) in sal plantation. Higher tree basal cover (51 m2/ha) was recorded in sal than chir pine (19 m2/ha). Similarly, the tree diversity in sal was recorded higher (1.68) as compared to chir pine (1.51) plantation. Contrarily, sapling diversity was higher (2.81) in chir pine as compared to sal (2.52) plantation. Herbaceous flora was completely absent in sal plantation. Analysis of size class distribution revealed that sal trees (~ 29%) attained 21-30 cm diameter whereas chir pine trees (68%) were under 11-20 cm diameter class mainly due to preferred growing zone of the species and habitat suitability. The soil under chir pine was slightly acidic (5.98) with sandy loam texture. Soil was comparatively good with higher soil organic carbon (2.71%) under sal plantation mainly due to high humus deposition. It is suggested to restrict wide spread of Lantana camara in chir pine plantation for the better growth of the species and enhance nutrient availability.