Exotic plants can potentially modify ecosystem functions like cycling of nutrients by adjusting their decomposition rates. However, these effects are largely unknown for urban ecosystems, though they act as reservoirs of exotic plants. The present study evaluated the decomposition rates of five native and five exotic (three invasive and two non-invasive) species by conducting the litter bag experiment. Our study, however, did not find any significant differences in overall decomposition rates of native and exotic species but decomposition rates were strongly correlated with initial chemical quality of the litter. Further, litter carbon, lignin to nitrogen ratio and carbon to nitrogen ratio seemed to be good predictors for decomposition rates in this study. Interestingly, invasive exotic species had higher decomposition rate while non-invasive exotic species showed a slower rate as compared to the native species. In conclusion, our study indicates that invasive exotic plants try to maintain a higher chemical quality of litter than native and non-invasive exotic species which promotes their rapid decomposition. Thus, the better chemical quality of litter may facilitate the naturalisation and invasion of exotic plants irrespective of their origin.

Kamala tree (Mallotus philippensis) is traditionally used by different ethnic groups to treat a variety of diseases and health ailments. However, these traditional uses need to be scientifically investigated and validated in order to develop drugs from this tree. Therefore, the present article is aimed to review the scientifically validated knowledge on the pharmacology and phytochemistry of the tree. To accomplish this, we extensively surveyed the available databases like Scopus, Web of Science, Google Scholar, ScienceDirect, NCBI including PubMed and PubChem, etc. by using keywords ‘Mallotus philippensis’, ‘Mallotus phillippinensis’ and ‘Mallotus philippinensis’. Our results indicated that the tree possesses more than 50 different types of important phytochemicals of natural origin. The wide array of phytochemicals possesses fascinating biological activities like anthelmintic, antibacterial, anti-inflammatory, anti-oxidant, anti-cancerous, anti-tuberculosis, anti-parasitic, analgesic, anti-urolithiatic and anti-viral activities. Thus, pharmacological activities and isolation of active phytochemicals make the tree a promising candidate for drug discovery. However, pharmacological activities such as antibacterial and anti-oxidant activities are often tested with crude extracts and in vitro rudimentary methods that can be sometimes misleading and non-specific. Thus, more sophisticated techniques may be applied for the isolation of active chemicals and elucidating their mechanism of actions.

Arundo donax L. (Giant reed) is a grass species belong to Poaceae family with a myriad of uses such as traditional and ethnomedicinal values, bioenergy, and socio-economic importance. The plant is used in conventional medicine to treat various disorders related to skin, gastrointestinal, skeletal, menstrual problems, respiratory and urinary diseases. The present review summarises the scattered information on socio-economic importance, ethnomedicinal uses, phytochemistry and pharmacological aspects of this plant. We conducted a rigorous literature survey using databases such as Scopus, Science Direct, Web of Science, Google Scholar, and PubMed entering keywords like A. donax, Giant reed, and Spanish reed, etc. Phytochemical investigations have identified several alkaloids, terpenoids, sterols, phenolics, and lignin derivatives. The isolated phytoconstituents are reported to exhibit multiple pharmacological activities such as anti-bacterial, anti-oxidant, anti-proliferative, anti-spasmolytic, and also used to treat helminthic infestations in cattle. However, the scientific validity of traditional practices to cure various diseases has not been correctly evaluated yet. Therefore, it is recommended to further investigate the plant for clinical trials to unleash its therapeutic importance towards chemical characterisation for drug discovery and development in the pharmacological field.

Justicia adhatoda, also known as Adulsa or Vasaka, is a notable member of the family Acanthaceae, with a broad geographic distribution across varied climatic conditions, and is known for its extensive medicinal properties for treating respiratory disorders, tuberculosis, malaria, and dysentery. It possesses several pharmacological activities, including anti-bacterial, anti-fungal, and anti-cancerous ones. In addition to discussing its morphology, phytochemistry, and pharmacological aspects, the present review also focuses on its several unexplored facets, such as pollination mechanism, cytology, molecular and genetic aspects, conservation, and ecological attributes. The literature survey indicates that, despite its medicinal value, J. adhatoda is also a strong invader in various ecosystems, suppressing associated species and cause vegetation homogenization. It also provides several ecosystem services, including soil stabilization, ecological restoration, and phytoremediation by removing contaminants such as chromium and mercury from wastewater. Additionally, its leaves increase the nitrogen content in compost, promote the proliferation of earthworms, and help suppress plant diseases. This highlights its potential for sustainable land management and integrated disease control. The urgency of this research is underscored by the significant gap in the literature regarding the ecological interactions of J. adhatoda, particularly its allelopathic effects on other plant species. The findings underscore the need for sustainable utilization and conservation strategies, emphasizing the dual importance of J. adhatoda as a medicinal resource and an ecological disruptor.

Habitat loss due to human activities and climate change is synergistically posing serious threats to the global biodiversity leading to irreversible extinction of several species. In wake of recent extinction, several forests are declared as protected areas where no more human activities are allowed. However, the scope of these protected areas got broadened from mere conservation to poverty alleviation and sustainable development during the past decades. Though these protected areas seem to be supportive of the biodiversity conservation, several challenges and gaps have emerged that need to be addressed for effective conservation and sustainable management in these protected areas. Therefore, the present chapter aims to address the roles, challenges, and approaches for conservation, and sustainable management in protected areas of India. Based on the published literature, we have found that protected areas proved to be a successful strategy for the conservation of wild animals and plants. However, management of poaching, man-wildlife conflicts, funding, extensive resource use, and tourism is still a challenge for some national parks of the country. Although governmental policies have addressed some of these challenges, only limited success has been achieved so far. Therefore, further studies need to assess the efficiency of protected areas for biodiversity conservation and devise the mechanisms for effective sustainable management of these protected areas.