Human impacts and Anthropocene environmental change at Lake Kutubu, a Ramsar wetland in Papua New Guinea

Abstract

The impacts of human-induced environmental change that characterize the Anthropocene are not felt equally across the globe. In the tropics, the potential for the sudden collapse of ecosystems in response to multiple interacting pressures has been of increasing concern in ecological and conservation research. The tropical ecosystems of Papua New Guinea are areas of diverse rainforest flora and fauna, inhabited by human populations that are equally diverse, both culturally and linguistically. These people and the ecosystems they rely on are being put under increasing pressure from mineral resource extraction, population growth, land clearing, invasive species, and novel pollutants. This study details the last ∼90 y of impacts on ecosystem dynamics in one of the most biologically diverse, yet poorly understood, tropical wetland ecosystems of the region. The lake is listed as a Ramsar wetland of international importance, yet, since initial European contact in the 1930s and the opening of mineral resource extraction facilities in the 1990s, there has been a dramatic increase in deforestation and an influx of people to the area. Using multiproxy paleoenvironmental records from lake sediments, we show how these anthropogenic impacts have transformed Lake Kutubu. The recent collapse of algal communities represents an ecological tipping point that is likely to have ongoing repercussions for this important wetland’s ecosystems. We argue that the incorporation of an adequate historical perspective into models for wetland management and conservation is critical in understanding how to mitigate the impacts of ecological catastrophes such as biodiversity loss.

Carbonates in the Critical Zone

“…Interdisciplinary research between social scientists, geographers, archaeologists, and earth scientists is required to better constrain the relationships between humans and karst landscapes. Human activity through the Anthropocene is negatively impacting the karst landscape (Beach et al., 2015; Long et al., 2021). This delicate environment is susceptible to soil degradation, sinkhole development, groundwater contamination, and depletion in groundwater levels.…”

Sediment Infill of Tropical Floodplain Lakes: Rates, Controls, and Implications for Ecosystem Services

“…Schiefer et al (2013) reported a steadily increasing lake sedimentation rate in the late 20th century in western Canada linked to the oil, gas, and timber extraction industries. Deforestation in much of the rest of the world increased rapidly during the late 20th century, which has frequently been recorded in lacustrine records (e.g., Roulet et al, 2000;Dearing and Jones, 2003;Long et al, 2021). Now, the Global South, consisting of many developing nations in the tropics, has overtaken developed nations in population growth and resource consumption (Chant and McIlwaine, 2009;Adams et al, 2019;State of the Tropics, 2020).…”

Carbonates in the Critical Zone

“…Interdisciplinary research between social scientists, geographers, archaeologists, and earth scientists is required to better constrain the relationships between humans and karst landscapes. Human activity through the Anthropocene is negatively impacting the karst landscape (Long et al, 2021;Beach et al, 2015). This delicate environment is susceptible to soil degradation, sinkhole development, groundwater contamination, and depletion in groundwater levels.…”