Naturalizing

Naturalizing, or naturalisation, is the legal process by which a person who is not a citizen acquires the citizenship or nationality of a country. In biology and ecology, naturalization refers to the process by which a non-native species becomes established and maintained in a new environment, effectively becoming part of the local ecosystem. The term is also used more broadly to describe the act of making something seem natural or ordinary within a given context, but this article focuses on citizenship and ecological senses.

In the citizenship sense, naturalization requires meeting statutory criteria set by the country, such as lawful residence for a specified period, language proficiency, knowledge of history and civic institutions, good moral character, and financial independence. Applicants typically submit an official application, supporting documents, and may undergo interviews, background checks, or exams. Successful applicants usually receive a naturalization certificate and may take an oath or pledge of allegiance, after which they are recognized as citizens and may receive a national passport.

Rights and obligations of naturalized citizens often parallel those of native-born citizens, including eligibility to vote, run for certain offices, and access to social services, subject to national law. Obligations may include tax compliance and, in some states, mandatory military or civil service; dual or multiple citizenship arrangements vary by country.

In ecology, a naturalized species is one that arrives in a non-native region, survives, reproduces, and sustains populations without human intervention. Naturalized species are not necessarily invasive, but some become ecologically disruptive. The term contrasts with native species and with species that are deliberately introduced but fail to establish.

See also: citizenship by naturalization, jus sanguinis, jus soli, naturalized citizen, immigration policy, invasive species.