scholarly journals Lack of reliable post-fire recovery mechanisms makes the iconic Tasmanian conifer Athrotaxis cupressoides susceptible to population decline

2021 ◽  
Author(s):  
Aimee Bliss ◽  
Lynda D. Prior ◽  
David M. J. S. Bowman
Keyword(s):  
Population Decline ◽  
Recovery Mechanisms

Ongoing population decline and range contraction in Norwegian forest grouse

2009 ◽  
Vol 32 (0) ◽  
pp. 179 ◽  
Author(s):  
Finn Gregersen ◽  
Håkon Gregersen
Keyword(s):  
Population Decline ◽  
Range Contraction

Modeling and optimizing logistics, information, economic and financial intercluster cooperation using the ant colony optimization algorithm

2020 ◽  
Vol 26 (11) ◽  
pp. 2427-2447
Author(s):  
S.N. Yashin ◽  
E.V. Koshelev ◽  
S.A. Borisov
Keyword(s):  
Ant Colony Optimization ◽  
Optimization Algorithm ◽  
Population Decline ◽  
Innovation System ◽  
Federal District ◽  
Original Model ◽  
Ant Colony ◽  
Industrial Agglomeration ◽  
Ant Colony Optimization Algorithm

Subject. This article discusses the issues related to the creation of a technology of modeling and optimization of economic, financial, information, and logistics cluster-cluster cooperation within a federal district. Objectives. The article aims to propose a model for determining the optimal center of industrial agglomeration for innovation and industry clusters located in a federal district. Methods. For the study, we used the ant colony optimization algorithm. Results. The article proposes an original model of cluster-cluster cooperation, showing the best version of industrial agglomeration, the cities of Samara, Ulyanovsk, and Dimitrovgrad, for the Volga Federal District as a case study. Conclusions. If the industrial agglomeration center is located in these three cities, the cutting of the overall transportation costs and natural population decline in the Volga Federal District will make it possible to qualitatively improve the foresight of evolution of the large innovation system of the district under study.

More than a “Petty Chief”: Understanding Fijian Chiefship through the Entrance Ceremony and Local History

1969 ◽  
Vol 61 (2) ◽  
pp. 213-226
Author(s):  
Hao-Li Lin
Keyword(s):  
Nineteenth Century ◽  
Population Decline ◽  
Local History

The diverse nature of Fiji’s chiefship and how its supremacy was strengthened by colonialism have already been closely examined. However, few studies have focused on village chiefs, who have limited authority and are at the lower end of regional chiefly hierarchies. Using both historical and ethnographic materials from a Fijian village, I argue here that its “petty chief,” as the role was called by nineteenth-century Westerners, is a powerful linkage to a past of stability represented by the chiefly title. This is particularly important for communities that have experienced historical turbulence. In this case study, it was mainly the measles crisis that caused population decline. The linkage is materialised by a standardised entrance ceremony in which the chiefly title is routinely acknowledged by foreign visitors through offerings (i-sevusevu) and thus elevated to a symbol that holds the community together. I also argue that the entrance ceremony that we observe today may have been prompted by Western contact. Through the analysis of the ceremony and local history, this study shows that the power of “petty chiefs” should be understood not solely by the structure of hierarchy, but also by their significance to historically turbulent communities.

Orchestrated Flowering and Interspecific Facilitation: Key Factors in the Maintenance of the Main Pollinator of Coexisting Threatened Species of Andean Wax Palms (Ceroxylon spp.)

2020 ◽  
Vol 105 (3) ◽  
pp. 281-299
Author(s):  
Javier Carreño-Barrera ◽  
Luis Alberto Núñez-Avellaneda ◽  
Maria José Sanín ◽  
Artur Campos D. Maia
Keyword(s):  
Conservation Status ◽  
Population Decline ◽  
Floral Biology ◽  
Fruit Production ◽  
Biological Data ◽  
Fruit Yield ◽  
Insect Species ◽  
Individual Species ◽  
Pollination Services ◽  
Flower Visiting

Solitary, dioecious, and mostly endemic to Andean cloud forests, wax palms (Ceroxylon Bonpl. ex DC. spp.) are currently under worrisome conservation status. The establishment of management plans for their dwindling populations rely on detailed biological data, including their reproductive ecology. As in the case of numerous other Neotropical palm taxa, small beetles are assumed to be selective pollinators of wax palms, but their identity and relevance in successful fruit yield were unknown. During three consecutive reproductive seasons we collected data on population phenology and reproductive and floral biology of three syntopic species of wax palms native to the Colombian Andes. We also determined the composition of the associated flower-visiting entomofauna, quantifying the extent of the role of individual species as effective pollinators through standardized value indexes that take into consideration abundance, constancy, and pollen transport efficiency. The studied populations of C. parvifrons (Engel) H. Wendl., C. ventricosum Burret, and C. vogelianum (Engel) H. Wendl. exhibit seasonal reproductive cycles with marked temporal patterns of flower and fruit production. The composition of the associated flower-visiting entomofauna, comprised by ca. 50 morphotypes, was constant across flowering seasons and differed only marginally among species. Nonetheless, a fraction of the insect species associated with pistillate inflorescences actually carried pollen, and calculated pollinator importance indexes demonstrated that one insect species alone, Mystrops rotundula Sharp, accounted for 94%–99% of the effective pollination services for all three species of wax palms. The sequential asynchronous flowering of C. parvifrons, C. ventricosum, and C. vogelianum provides an abundant and constant supply of pollen, pivotal for the maintenance of large populations of their shared pollinators, a cooperative strategy proven effective by high fruit yield rates (up to 79%). Reproductive success might be compromised for all species by the population decline of one of them, as it would tamper with the temporal orchestration of pollen offer.

Distributed C2 System Recovery Mechanisms

1988 ◽  
Author(s):  
William T. Wood ◽  
Helmut K. Berg ◽  
Anand R. Tripathi ◽  
Jonathan Silverman ◽  
Elaine N. Frankowski
Keyword(s):  
Recovery Mechanisms
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