Stable Isotopic Evidence for Nutrient Rejuvenation and Long-Term Resilience on Tikopia Island (Southeast Solomon Islands)

Tikopia Island, a small and relatively isolated Polynesian Outlier in the Southeast Solomon Islands, supports a remarkably dense human population with minimal external support. Examining long-term trends in human land use on Tikopia through archaeological datasets spanning nearly 3000 years presents an opportunity to investigate pathways to long-term sustainability in a tropical island setting. Here, we trace nutrient dynamics across Tikopia’s three pre-European contact phases (Kiki, Sinapupu, Tuakamali) via stable carbon and nitrogen isotope analysis of commensal Pacific rat (Rattus exulans) and domestic pig (Sus scrofa) bone and tooth dentine collagen. Our results show a decline in δ15N values from the Kiki (c. 800 BC-AD 100) to Sinapupu (c. AD 100–1200) phases, consistent with long-term commensal isotope trends observed on other Polynesian islands. However, increased δ15N coupled with lower δ13C values in the Tuakamali Phase (c. AD 1200–1800) point to a later nutrient rejuvenation, likely tied to dramatic transformations in agriculture and land use at the Sinapupu-Tuakamali transition. This study offers new, quantifiable evidence for deep-time land and resource management decisions on Tikopia and subsequent impacts on island nutrient status and long-term sustainability.

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Restructuring of nutrient flows in island ecosystems following human colonization evidenced by isotopic analysis of commensal rats

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1805787115 ◽

2018 ◽

Vol 115 (25) ◽

pp. 6392-6397 ◽

Cited By ~ 6

Author(s):

Jillian A. Swift ◽

Patrick Roberts ◽

Nicole Boivin ◽

Patrick V. Kirch

Keyword(s):

Land Use ◽

Stable Isotope ◽

Stable Isotope Analysis ◽

Human Activities ◽

Isotope Analysis ◽

Island Ecosystems ◽

Nutrient Flows ◽

Isotope Data ◽

Human Land Use ◽

Human Colonization

The role of humans in shaping local ecosystems is an increasing focus of archaeological research, yet researchers often lack an appropriate means of measuring past anthropogenic effects on local food webs and nutrient cycling. Stable isotope analysis of commensal animals provides an effective proxy for local human environments because these species are closely associated with human activities without being under direct human management. Such species are thus central to nutrient flows across a range of socionatural environments and can provide insight into how they intersected and transformed over time. Here we measure and compare stable carbon and nitrogen isotope data from Pacific rat (Rattus exulans) skeletal remains across three Polynesian island systems [Mangareva, Ua Huka (Marquesas), and the Polynesian Outlier of Tikopia] during one of the most significant cases of human migration and commensal introduction in prehistory. The results demonstrate widespread δ15N declines across these islands that are associated with human land use, intensification, and faunal community restructuring. Local comparison of rat stable isotope data also tracks human activities and resource availability at the level of the settlement. Our results highlight the large-scale restructuring of nutrient flows in island ecosystems that resulted from human colonization and ecosystem engineering activities on Pacific islands. They also demonstrate that stable isotope analysis of often-ignored commensal taxa can provide a tool for tracking human land use and environmental effects.

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Human Land-Use Practices Lead to Global Long-Term Increases in Photosynthetic Capacity

Remote Sensing ◽

10.3390/rs6065717 ◽

2014 ◽

Vol 6 (6) ◽

pp. 5717-5731 ◽

Cited By ~ 32

Author(s):

Thomas Mueller ◽

Gunnar Dressler ◽

Compton Tucker ◽

Jorge Pinzon ◽

Peter Leimgruber ◽

...

Keyword(s):

Land Use ◽

Photosynthetic Capacity ◽

Human Land Use ◽

Land Use Practices

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Proposed approaches to systematic planning of research and monitoring to support a South African inland fisheries policy

Water SA ◽

10.17159/wsa/2021.v47.i3.11865 ◽

2021 ◽

Vol 47 (3 July) ◽

Author(s):

S Hugo ◽

OLF Weyl

Keyword(s):

Land Use ◽

South African ◽

Catch Per Unit Effort ◽

Inland Fisheries ◽

Model Based ◽

Human Land Use ◽

Unit Effort ◽

Fisheries Policy ◽

Systematic Planning

A South African inland fisheries policy will depend on a reliable long-term supply of social-ecological data covering freshwater fisheries at a broad geographic scale. Approaches to systematic planning of research and monitoring are demonstrated herein, based on a fishery-independent gillnet dataset covering 44 dams, and geographic information system maps of monthly and annual climate variables, human land use, and road access in a 5 km zone around 442 dams. Generalised linear mixed models were used to determine the covariates of gillnet catch per unit effort. Such covariates are required for a model-based process to select a subset of state-owned dams for a long-term fishery survey programme. The models indicated a monthly climate influence on catch per unit effort and climatic drivers of fish species distributions. However, unexplained variation is overwhelming and precludes a model-based survey design process. Non-hierarchical clustering of 442 dams was then done based on annual climate and human land use variables around dams. The resulting clusters of dams with shared climate and land use characteristics indicates the types of dams that should be selected for monitoring to represent the full range of climate and land use characteristics. Surrounding land use could indicate the socioeconomic characteristics of fisheries, for example, dams that may support subsistence-based communities that require increased research effort. Finally, although primary catchments could be useful for organising national-scale management, land use cover in the 5 km zone around dams varied widely within the respective primary catchments. Beyond these proposed approaches to plan research, this study also reveals various data deficiencies and recommends additional future studies on other possible methods for systematic research planning.

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Quantifying Differential Responses to Fruit Abundance by Two Rainforest Birds Using Long-Term Isotopic Monitoring

The Auk ◽

10.1093/auk/122.3.783 ◽

2005 ◽

Vol 122 (3) ◽

pp. 783-792 ◽

Cited By ~ 1

Author(s):

L. Gerardo Herrera M. ◽

Keith A. Hobson ◽

Patricia Hernández C. ◽

Malinalli Rodríguez G.

Keyword(s):

Isotope Analysis ◽

Nitrogen Isotope ◽

Stable Nitrogen Isotope ◽

Fruit Abundance ◽

Fruit Species ◽

One Year ◽

Mionectes Oleagineus ◽

The Tropics ◽

Plant Sources

Abstract Most tropical passerines feed on insects, fruit, or a combination of the two. The sugary pulps of fruit have lower amounts of protein than insects. We used stable-nitrogen isotope analysis (δ15N) of blood from two tropical rainforest birds that regularly feed on fruit—Red-throated Ant-Tanager (Habia fuscicauda) and Ochre-bellied Flycatcher (Mionectes oleagineus)—to quantify the relative amounts of assimilated protein from animal and plant sources. Because fruit and insect abundances vary seasonally in the tropics, the study was conducted during one year in Los Tuxtlas, Mexico. The study site has one major fruiting peak between April and July and a secondary peak between September and October. Some insects are more abundant from May to August. Red-throated Ant-Tanagers and Ochre-bellied Flycatchers rely heavily on insect protein when fruit is scarce, and then steadily increase their input of fruit protein as fruit abundance increases. Red-throated Ant-Tanagers rely almost entirely on fruit protein during the major fruiting peak, whereas Ochre-bellied Flycatchers have the largest input of fruit protein during the secondary fruit peak. Incubation in both species occurs from June to August, and most incubating individuals rely on a mixture of insects and fruit. In both species, examination of fecal contents showed the ingestion of the largest number of fruit species during the major fruiting peak. Cuantificación de la Respuesta Diferencial a la Abundancia de Frutos por Dos Especies de Aves Selváticas Mediante el Monitoreo Isotópico a Largo Plazo

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Nitrogen availability determines the long-term impact of land-use change on soil carbon stocks in grasslands of southern Ghana

10.5194/soil-2020-18 ◽

2020 ◽

Author(s):

John Kormla Nyameasem ◽

Thorsten Reinsch ◽

Friedhelm Taube ◽

Charles Yaw Fosu Domozoro ◽

Esther Marfo-Ahenkora ◽

...

Keyword(s):

Land Use ◽

Nitrogen Availability ◽

Agricultural Soils ◽

Soil Nutrient ◽

Critical Factor ◽

Nutrient Status ◽

Long Term Impact ◽

The Impact ◽

Soc Stocks

Abstract. Enhancing the capacity of agricultural soils to resist soil degradation and to mitigate climate change requires long-term assessments of land-use systems. Such long-term evaluations, particularly regarding low-input livestock systems, are limited. This study evaluated the impact of long-term land-use practices, condensed tannins (CT) and soil nutrient status on carbon cycling in arable and permanent systems of a tropical Savannah. Soil samples were taken (0–30 cm depth) from arable crop fields, grazed-seeded grassland, cut-use permanent crops and native grassland. Soil organic carbon (SOC) stocks ranged from 19.9 to 36.8 Mg SOC ha−1 (mean ± sd = 32.9 ± 0.2 Mg ha−1). SOC stocks were lower for grazed-seeded grassland relative to cut-use grass, legume trees and shrubs. Within sown systems, nitrogen availability seemed to be the most critical factor that determines the fate of the SOC stocks, with soil nitrogen (N) concentration and the SOC being highly correlated (r = 0.90; p

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Anthropogenic impact on biogenic Si pools in temperate soils

Biogeosciences Discussions ◽

10.5194/bgd-8-4391-2011 ◽

2011 ◽

Vol 8 (3) ◽

pp. 4391-4419 ◽

Cited By ~ 4

Author(s):

W. Clymans ◽

E. Struyf ◽

G. Govers ◽

F. Vandevenne ◽

D. J. Conley

Keyword(s):

Land Use ◽

Agricultural Development ◽

Land Use Changes ◽

Arable Land ◽

Terrestrial Ecosystems ◽

Human Land Use ◽

Long Term Effect ◽

Disturbed Land ◽

The Impact

Abstract. Human land use changes directly affect silica (Si) mobilisation and Si storage in terrestrial ecosystems and influence Si export from the continents, although the magnitudes of the impact are unknown. Yet biogenic silica (BSi) in soils is an understudied aspect. We have quantified and compared total biogenic (PSia) and easily soluble (PSie) Si pools at four sites along a gradient of disturbance in southern Sweden. An estimate of the magnitude of change in temperate continental BSi pools due to human disturbance is provided. Land use clearly affects BSi pools and their distribution. Total PSia and PSie for a continuous forested site at Siggaboda Nature Reserve (66 900 ± 22 800 kg SiO2 ha−1 and 952 ± 16 kg SiO2 ha−1) are significantly higher than disturbed land use types from the Råshult Culture Reserve including arable land (28 800 ± 7200 kg SiO2 ha−1 and 239 ± 91 kg SiO2 ha−1), pasture sites (27 300 ± 5980 kg SiO2 ha−1 and 370 ± 129 kg SiO2 ha−1) and grazed forest (23 600 ± 6370 kg SiO2 ha−1 and 346 ± 123 kg SiO2 ha−1). Vertical PSia and PSie profiles show significant (p<0.05) variation among the sites. These differences in size and distribution are interpreted as the long-term effect of reduced BSi replenishment and increased mobilisation of the PSia in disturbed soils. In temperate regions, total PSia showed a 10 % decline since agricultural development (3000BCE). Recent agricultural expansion (after 1700CE) has resulted in an average export of 1.1 ± 0.8 Tmol Si yr−1, leading to an annual contribution of ca. 20 % to the global land-ocean Si flux carried by rivers. Human activities clearly exert a long-term influence on Si cycling in soils and contribute significantly to the land-ocean Si flux.

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Assessment of Terrigenous Nutrient Loading to Coastal Ecosystems along a Human Land-Use Gradient, Tutuila, American Samoa

Hydrology ◽

10.3390/hydrology6010018 ◽

2019 ◽

Vol 6 (1) ◽

pp. 18 ◽

Cited By ~ 7

Author(s):

Christopher Shuler ◽

Daniel Amato ◽

Veronica Veronica Gibson ◽

Lydia Baker ◽

Ashley Olguin ◽

...

Keyword(s):

Land Use ◽

Nutrient Loading ◽

Water Discharge ◽

Nitrogen Isotope ◽

Nutrient Flux ◽

American Samoa ◽

Nutrient Concentrations ◽

Human Land Use ◽

The Impact

Anthropogenic nutrient loading is well recognized as a stressor to coastal ecosystem health. However, resource managers are often focused on addressing point source or surface water discharge, whereas the impact of submarine groundwater discharge (SGD) as a nutrient vector is often unappreciated. This study examines connections between land use and nutrient loading through comparison of four watersheds and embayments spanning a gradient of human use impact on Tutuila, a high tropical oceanic island in American Samoa. In each study location, coastal radon-222 measurements, dissolved nutrient concentrations, and nitrogen isotope values (δ15N) in water and in situ macroalgal tissue were used to explore SGD and baseflow derived nutrient impacts, and to determine probable nutrient sources. In addition to sampling in situ macroalgae, pre-treated macroalgal specimens were deployed throughout each embayment to uptake ambient nutrients and provide a standardized assessment of differences between locations. Results show SGD-derived nutrient flux was more significant than baseflow nutrient flux in all watersheds, and δ15N values in water and algae suggested wastewater or manure are likely sources of elevated nutrient levels. While nutrient loading correlated well with expected anthropogenic impact, other factors such as differences in hydrogeology, distribution of development, and wastewater infrastructure also likely play a role in the visibility of impacts in each watershed.

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Two Thousand Years of Land-Use and Vegetation Evolution in the Andean Highlands of Northern Chile Inferred from Pollen and Charcoal Analyses

Quaternary ◽

10.3390/quat1030032 ◽

2018 ◽

Vol 1 (3) ◽

pp. 32 ◽

Cited By ~ 3

Author(s):

Alejandra Domic ◽

José Capriles ◽

Katerine Escobar-Torrez ◽

Calogero Santoro ◽

Antonio Maldonado

Keyword(s):

Land Use ◽

Environmental Changes ◽

Management Strategies ◽

Northern Chile ◽

Human Land Use ◽

Climatic Drivers ◽

Land Use And Management ◽

Andean Highlands ◽

The Last Two Millennia

The European conquest of the New World produced major socio-environmental reorganization in the Americas, but for many specific regions and ecosystems, we still do not understand how these changes occurred within a broader temporal framework. In this paper, we reconstruct the long-term environmental and vegetation changes experienced by high-altitude wetlands of the southcentral Andes over the last two millennia. Pollen and charcoal analyses of a 5.5-m-long core recovered from the semi-arid puna of northern Chile indicate that while climatic drivers influenced vegetation turnaround, human land use and management strategies significantly affected long-term changes. Our results indicate that the puna vegetation mostly dominated by grasslands and some peatland taxa stabilized during the late Holocene, xerophytic shrubs expanded during extremely dry events, and peatland vegetation persisted in relation to landscape-scale management strategies by Andean pastoralist societies. Environmental changes produced during the post-conquest period included the introduction of exotic taxa, such as clovers, associated with the translocation of exotic herding animals (sheep, cattle, and donkeys) and a deterioration in the management of highland wetlands.

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Land use, water and Mediterranean landscapes: modelling long-term dynamics of complex socio-ecological systems

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2010.0193 ◽

2010 ◽

Vol 368 (1931) ◽

pp. 5275-5297 ◽

Cited By ~ 42

Author(s):

C. Michael Barton ◽

Isaac I. Ullah ◽

Sean Bergin

Keyword(s):

Land Use ◽

Spatial Scales ◽

Computational Modelling ◽

Ecological Systems ◽

Land Use Land Cover ◽

Human Land Use ◽

Complex Interactions ◽

Mediterranean Landscapes ◽

Temporal And Spatial

The evolution of Mediterranean landscapes during the Holocene has been increasingly governed by the complex interactions of water and human land use. Different land-use practices change the amount of water flowing across the surface and infiltrating the soil, and change water’s ability to move surface sediments. Conversely, water amplifies the impacts of human land use and extends the ecological footprint of human activities far beyond the borders of towns and fields. Advances in computational modelling offer new tools to study the complex feedbacks between land use, land cover, topography and surface water. The Mediterranean Landscape Dynamics project (MedLand) is building a modelling laboratory where experiments can be carried out on the long-term impacts of agropastoral land use, and whose results can be tested against the archaeological record. These computational experiments are providing new insights into the socio-ecological consequences of human decisions at varying temporal and spatial scales.

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Long-term field experiments – museum relics or scientific challenge?

Plant Soil and Environment ◽

10.17221/395-pse ◽

2008 ◽

Vol 54 (No. 5) ◽

pp. 219-226 ◽

Cited By ~ 12

Author(s):

W. Merbach ◽

A. Deubel

Keyword(s):

Land Use ◽

Climatic Change ◽

Nutrient Dynamics ◽

Field Experiments ◽

Soil Formation ◽

Formation Processes ◽

Microbial Biodiversity ◽

Scientific Challenge ◽

Term Field

By reference to the Eternal Rye trial in Halle, Germany, as an example, it is demonstrated that long-term trials provide indispensable information for contemporary and future land use research. These trials serve as tools for the examination of cultivation measures or the effects of climate on nutrient dynamics and mobilization, microbial biodiversity, mineral composition or soil formation processes. They are therefore essential for the evaluation of land-use strategies or climatic change and, because of that, can provide more accuracy in related political considerations.

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