Journal of Basic and Applied Research International

Nature-based solutions have become the organising vocabulary for landscape investment in eastern India, yet the concept arrived in Bihar and Jharkhand already loaded with expectations that the regional evidence base has not been asked to justify. These two states occupy contrasting ends of a single socio-ecological gradient: an aggrading, flood-dominated Middle Gangetic floodplain with almost no forest, and an eroding, drought-prone plateau of red lateritic soils carrying most of the region's remaining tree cover, mineral wealth and Adivasi population. This review critically examines what is known, and what is merely assumed, about the capacity of nature-based interventions to deliver biodiversity conservation and livelihood security across this gradient. Peer-reviewed literature and institutional evidence were identified through iterative searching of Crossref, Google Scholar, the Directory of Open Access Journals and Semantic Scholar, supplemented by citation tracking and targeted searches of institutional repositories, with a final search date of 22 July 2026. Five findings emerge. First, the intervention families most heavily funded in the region, namely block plantation and compensatory afforestation, rest on the weakest biodiversity evidence, while those with the strongest ecological rationale, namely floodplain reconnection and wetland restoration, receive the least investment. Second, livelihood benefits are documented mainly as gross income from forest and wetland products rather than as net welfare change against a defensible counterfactual, so the standard claim of joint biodiversity and livelihood gain remains largely untested regionally. Third, hydrological interventions in Bihar are constrained less by ecological knowledge than by an embankment-centred engineering regime that forecloses the reconnection options nature-based approaches require. Fourth, tenure and rulemaking authority, rather than technical design, explain most of the variation in outcomes that the available studies can detect. Fifth, the region has no monitoring architecture capable of attributing ecological or welfare change to any intervention. The evidence supports cautious optimism about targeted, tenure-secure, ecosystem-specific interventions, and does not support the broader claim that nature-based solutions can simultaneously resolve biodiversity loss and livelihood insecurity at the scale at which they are currently promoted.