Discontinuities in sediment connectivity controlled by human-environment interaction along the sediment cascade of a mesoscale catchment in Central Germany

Author(s):  
Markus Fuchs ◽  
Raphael Steup ◽  
Katja Korthiringer ◽  
Timo Seregely

<p>In many Central European river catchments changes in long-term sediment dynamics are caused by external driving forces (e.g. human impact, climate change). In addition, the sensitivity of fluvial systems to environmental change is controlled by the catchment’s geomorphic connectivity of individual sediment sinks. In this study, we reconstruct the temporal evolution of different types of sediment reservoirs along the sediment cascade in a mesoscale upland catchment to assess its sensitivity to external changes. The chronological evolution of hillslope and floodplain sediments is based on 79 OSL and 83 C<sup>14</sup> ages. Our results show that deposition of hillslope sediments coincides with the first evidence for human-induced soil erosion triggered by the earliest European farmers, but were decoupled from the river network for more than two millennia when the aggradation of overbank fines started and steadily increased. Therefore, the connectivity between the colluvial and alluvial sediment sinks of the catchment is mainly controlled by the landscape geometry and frequency and magnitude of erosion, transport and deposition processes.</p>

2003 ◽  
Vol 06 (04) ◽  
pp. 631-644 ◽  
Author(s):  
STEFANO BATTISTON ◽  
GÉRARD WEISBUCH ◽  
ERIC BONABEAU

The boards of large corporations sharing some of their directors are connected in complex networks. Boards are responsible for corporations' long-term strategy and are often involved in decisions about a common topic related to the belief in economical growth or recession. We are interested in understanding under which conditions a large majority of boards making the same decision can emerge in the network. We present a model where board directors are engaged in a decision-making dynamics based on "herd behavior." Boards influence each other through shared directors. We find that imitation of colleagues and opinion bias due to the interlock do not trigger an avalanche of identical decisions over the board network, whereas the information about interlocked boards' decisions does. There is no need to invoke global public information, nor external driving forces. This model provides a simple endogenous mechanism to explain the fact that boards of the largest corporations of a country can, in the span of a few months, make the same decisions about general topics.


2014 ◽  
Vol 12 (2) ◽  
pp. 119-139 ◽  
Author(s):  
Matthew Pawlowicz ◽  
John Stoetzel ◽  
Stephen Macko

The historic port town of Mikindani is situated along the southern portion of the Swahili coast. Archaeological investigations in this region of coastal East Africa yield evidence of occupation since the last centuries BCE and intensive settlement since the middle of the first millennium CE. This long settlement history suggests that people in the region have had an expansive, wide-ranging impact on local ecological conditions in the region. This paper takes a historical ecology approach in evaluating the nature and degree of anthropogenic influences on the environment in and around Mikindani. The evaluation is based on evidence from contemporary botanical communities, faunal remains, macrobotanicals, phytolith residues, isotope analysis of archaeological sediments, and soil chemistry. This research also looks to define an environmental component that contributes to a previously defined mercantile culture that characterizes Swahili communities in the region. We argue that this interdisciplinary analysis yields evidence of several long-term anthropogenic influences in Mikindani, including: a long-term reduction in forests and woody vegetation, reliance on shifting agriculture as a subsistence strategy, and the continued reliance on marine resources to meet subsistence needs. These patterns of human-environment interaction help suggest reasons for certain developments in Mikindani’s history, perhaps most notably its early second millennium CE absence from Indian Ocean trade networks. Our results contribute to a growing literature in East Africa which acknowledges that modern environments of East Africa derive from a recursive relationship with human populations that has continued for thousands of years.


Polar Record ◽  
2021 ◽  
Vol 57 ◽  
Author(s):  
Frigga Kruse ◽  
Gary R. Nobles ◽  
Martha de Jong ◽  
Rosanne M. K. van Bodegom ◽  
G. J. M. (Gert) van Oortmerssen ◽  
...  

Abstract Arctic mining has a bad reputation because the extractive industry is often responsible for a suite of environmental problems. Yet, few studies explore the gap between untouched tundra and messy megaproject from a historical perspective. Our paper focuses on Advent City as a case study of the emergence of coal mining in Svalbard (Norway) coupled with the onset of mining-related environmental change. After short but intensive human activity (1904–1908), the ecosystem had a century to respond, and we observe a lasting impact on the flora in particular. With interdisciplinary contributions from historical archaeology, archaeozoology, archaeobotany and botany, supplemented by stable isotope analysis, we examine 1) which human activities initially asserted pressure on the Arctic environment, 2) whether the miners at Advent City were “eco-conscious,” for example whether they showed concern for the environment and 3) how the local ecosystem reacted after mine closure and site abandonment. Among the remains of typical mining infrastructure, we prioritised localities that revealed the subtleties of long-term anthropogenic impact. Significant pressure resulted from landscape modifications, the import of non-native animals and plants, hunting and fowling, and the indiscriminate disposal of waste material. Where it was possible to identify individual inhabitants, these shared an economic attitude of waste not, want not, but they did not hold the environment in high regard. Ground clearances, animal dung and waste dumps continue to have an effect after a hundred years. The anthropogenic interference with the fell field led to habitat creation, especially for vascular plants. The vegetation cover and biodiversity were high, but we recorded no exotic or threatened plant species. Impacted localities generally showed a reduction of the natural patchiness of plant communities, and highly eutrophic conditions were unsuitable for liverworts and lichens. Supplementary isotopic analysis of animal bones added data to the marine reservoir offset in Svalbard underlining the far-reaching potential of our multi-proxy approach. We conclude that although damaging human–environment interactions formerly took place at Advent City, these were limited and primarily left the visual impact of the ruins. The fell field is such a dynamic area that the subtle anthropogenic effects on the local tundra may soon be lost. The fauna and flora may not recover to what they were before the miners arrived, but they will continue to respond to new post-industrial circumstances.


1997 ◽  
Vol 2 (1) ◽  
pp. 27-46 ◽  
Author(s):  
Susan K. Jacohson ◽  
John J. Arana ◽  
Mallory D. McDuff

The increasing cultural and ethnic diversity in the United States should challenge environmental interpreters to offer programs that attract a variety of audiences. This study investigated minority involvement at Florida's nature centers through a census of 77 nature center directors throughout Florida as well as a survey of 21 minority staff working at these educational facilities. School programs at the nature centers are the primary method for reaching minorities; few programs involve minority adults from the community. The focus of the one-day visits for students is primarily nature awareness, with little emphasis on influencing knowledge or attitudes about local issues, human-environment relationships, or actions to reduce environmental problems. The results indicate the need for nature centers to expand their programs to offer long-term, community-based environmental interpretation for a diverse public.


2019 ◽  
Vol 11 (21) ◽  
pp. 6041 ◽  
Author(s):  
Zhang ◽  
Li ◽  
Buyantuev ◽  
Bao ◽  
Zhang

Ecosystem services management should often expect to deal with non-linearities due to trade-offs and synergies between ecosystem services (ES). Therefore, it is important to analyze long-term trends in ES development and utilization to understand their responses to climate change and intensification of human activities. In this paper, the region of Uxin in Inner Mongolia, China, was chosen as a case study area to describe the spatial distribution and trends of 5 ES indicators. Changes in relationships between ES and driving forces of dynamics of ES relationships were analyzed for the period 1979–2016 using a stepwise regression. We found that: the magnitude and directions in ES relationships changed during this extended period; those changes are influenced by climate factors, land use change, technological progress, and population growth.


2016 ◽  
Vol 49 (6) ◽  
pp. 065402 ◽  
Author(s):  
Franz G Mertens ◽  
Fred Cooper ◽  
Niurka R Quintero ◽  
Sihong Shao ◽  
Avinash Khare ◽  
...  

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