Language extinction is accelerating, with 30% of recorded extinctions having occurred since 1960.

Language vulnerability to extinction depends on speakers’ attitudes toward their languages as well as on socioeconomic factors. However, quantitative evidence on the relative impact of individual drivers of language endangerment is almost non-existent, making it impossible to understand and predict language attrition.

Furthermore, language skills and ethno-biological knowledge are rarely examined in relation to socio-economic variables for individual speakers, as required for mechanistic understanding of language attrition and loss of ethno-biological knowledge.

Papua New Guinea is the world’s most linguistically diverse nation, where about nine million people speak about 840 highly diverse languages, classified into at least 33 families.

Until recently, these languages enjoyed widespread vitality due to the absence of a dominant language in the region, stable small-scale multilingualism, and focus on language as a marker of group identity.

New Guinea is also the world’s most floristically diverse island, comprising about 5% of the world’s biodiversity.

Throughout PNG, numerous indigenous communities have explored, systematised, used and managed the extraordinary biodiversity in their natural environment, thus generating extensive biocultural knowledge of local ecosystems.

The traditional environmental knowledge of indigenous communities is in decline worldwide in response to the forces of cultural and economic globalization.

Only 20% of PNG’s ethno-linguistic groups have any of their traditional plant uses recorded in the literature, and detailed information (more than 100 plant-use records) exists for only 2.5% of groups. Likewise, the contemporary status on this knowledge remains poorly documented.

At present, 32% of indigenous languages in PNG are considered endangered largely due to their replacement by Tok Pisin (an English-based creole and PNG’s major lingua franca) or English (the language of formal education).

However, the true status of the country’s languages cannot be assessed in the absence of a national linguistic survey……

The traditional multilingualism in indigenous languages in the present oldest generation has given way to bilingualism with Tok Pisin in an intermediate generation and monolingualism in Tok Pisin, with perhaps English from schooling, in a third generation.

Unfortunately, we have shown that ethnobiological knowledge is closely correlated with indigenous language skills and therefore equally at risk.

The factors predicting language and biocultural-knowledge attrition in our models are determined by the factors considered desirable in contemporary PNG society, such as education, cash economy, ease of travel, and skills demanded for employment, or they are a consequence of economic development such as urbanization, which also leads to mixed-language marriages.

These powerful forces are making the preservation of traditional knowledge difficult. In 2013, PNG abandoned a decades-long experiment in allowing local communities to deliver early childhood education in local indigenous languages by moving to an English-only plan.

Furthermore, children often leave their home village to pursue education, which can cause attrition of their indigenous language skills.

PNG’s extraordinary linguistic diversity and overwhelmingly rural population pose a challenge for state-delivered education but have played an important role in the retention of vast biocultural knowledge that exists outside the education system.

The survival of most indigenous languages and traditional knowledge will be determined by factors other than their practicality. On a positive note, PNG communities prize language as a marker of group identity.

A majority, 88%, of the students fluent in an indigenous language expressed their intention to teach it to their children, but only 8% were motivated by practicality for communication, while the others valued language as an important part of their culture.

It is possible that biocultural knowledge is less consciously prized than language skills and therefore even more in danger of disappearing than indigenous languages.

The nation’s linguistic and biological diversity continue to be extensively studied with some sustained efforts at protection.

Grassroots programs could reinvigorate the interest of indigenous communities in their ethnobiological heritage as well as in the preservation of linguistic and biological diversity