scholarly journals Marine seafood production via intense exploitation and cultivation in China: Costs, benefits, and risks

PLoS ONE ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. e0227106 ◽  
Author(s):  
Cody Szuwalski ◽  
Xianshi Jin ◽  
Xiujuan Shan ◽  
Tyler Clavelle
Keyword(s):  
Intense Exploitation

scholarly journals Wildlife and Land Use in Highland Scotland

Oryx ◽  
1973 ◽  
Vol 12 (1) ◽  
pp. 53-63
Author(s):  
James Lockie
Keyword(s):  
Land Use ◽  
Seventeenth Century ◽  
Red Deer ◽  
Management Practices ◽  
Red Fox ◽  
Land Uses ◽  
Red Grouse ◽  
Scottish Highlands ◽  
Wildlife Species ◽  
Intense Exploitation

Depopulation of the Scottish Highlands in the seventeenth century was followed by intense exploitation and often misuse of the land, with serious overgrazing, burning and wildlife destruction. Today the main land uses are hill sheep farming, crofting, sport, and, more recently, commercial timber growing, nature conservation, hydroelectric schemes and tourism. The author, who is on the staff of the Department of Forestry and Natural Resources in Edinburgh University, examines the effect of these activities on four main wildlife species – golden eagle, red deer, red grouse and red fox – and describes some of the mistaken management practices which damage the wildlife, often without producing the desired results.

scholarly journals Growth, photosynthesis and stress indicators in young rosewood plants (Aniba rosaeodora Ducke) under different light intensities

2005 ◽  
Vol 17 (3) ◽  
pp. 325-334 ◽  
Author(s):  
José Francisco de Carvalho Gonçalves ◽  
Denize Caranhas de Sousa Barreto ◽  
Ulysses Moreira dos Santos Junior ◽  
Andreia Varmes Fernandes ◽  
Paulo de Tarso Barbosa Sampaio ◽  
...  
Keyword(s):  
Photochemical Efficiency ◽  
Biomass Accumulation ◽  
Photosynthetic Performance ◽  
High Irradiance ◽  
Relative Growth Rates ◽  
Full Sunlight ◽  
Light Intensities ◽  
The Family ◽  
Protection Mechanisms ◽  
Intense Exploitation

Aniba rosaeodora is an Amazonian tree species that belongs to the family Lauraceae. Due to intense exploitation for extraction of essential oils (mainly linalol), A. rosaeodora is now considered an endangered species. On the other hand, there is little information about its ecophysiology which would be useful to support future forest planting programs. Hence, the effect of different light intensities on the growth and photosynthetic characteristics of young plants of A. rosaeodora was studied. Nine-month-old plants were subjected to four light treatments (T1= 10 a 250 µmol.m-2.s-1 / control; T2=500 to 800, T3=700 to 1000 and T4=1300 to 1800 µmol.m-2.s-1 / full sunlight). Allometric variables, gas exchange, contents of pigments and chlorophyll a fluorescence were analysed. As to the relative growth rates, it was found that plants of A. rosaeodora showed higher biomass accumulation when grown under intermediary irradiance conditions (T2). The best photosynthetic performance was achieved under conditions of T3. When growth was correlated with photosynthesis, it was found that plants under treatments T2 and T3 presented better responses in comparison with the lowest (T1) and highest (T4) light extremes. The highest pigment contents were obtained for plants in the shade (T1) and the lowest for those exposed to full sunlight (T4). The photochemical efficiency of photosystem II (Fv/Fm) was found that only plants in the shade treatment (T1) presented no stress from high irradiance. These findings suggest that both treatments (T1 and T4) altered the function of the A. rosaeodora plants, inhibiting photosynthesis and growth. Plants of A. rosaeodora developed photo-protection mechanisms under full sunlight. However, the species presented better photosynthetic response and biomass gain under intermediary irradiance conditions, displaying relative physiological plasticity, during the seedling phase.

scholarly journals Enjeux et amélioration de la gestion des espèces du genre Entandrophragma, arbres africains devenus vulnérables

2019 ◽  
Vol 339 ◽  
pp. 75 ◽  
Author(s):  
Emmanuel Kasongo Yakusu ◽  
Dominique Louppe ◽  
Franck S. Monthe ◽  
Olivier J. Hardy ◽  
Félicien Bola Mbele Lokanda ◽  
...  
Keyword(s):  
Distribution Spatiale ◽  
Sont Encore ◽  
Régénération Naturelle ◽  
Intense Exploitation

Par la qualité de leur bois et leurs nombreux usages traditionnels, les espèces du genre Entandrophragma font l’objet d’une intense exploitation, susceptible de compromettre leur pérennité en l’absence de gestion durable. La présente étude dresse un état de la situation de cinq espèces commerciales principales de ce genre : Entandrophragma angolense, E. congoense (souvent assimilée par erreur à E. angolense), E. candollei, E. cylindricum et E. utile. Elle propose des pistes de recherche pour améliorer les stratégies de gestion durable au sein de ce genre. L’étude est principalement basée sur les données scientifiques (publications), économiques (statistiques de production et d’exportation) et juridiques (lois et réglementations), mais aussi sur les plans d’aménagement et les rapports d’inventaire. Les connaissances sur leur gestion sont encore fragmentaires alors qu’elles sont considérées comme vulnérables dans la liste rouge de l’UICN. La forte exploitation industrielle ou artisanale de ces espèces ne s’effectue pas toujours dans le respect d’un plan d’aménagement validé, ni de la durée minimum des rotations qui permettraient l’un et l’autre un taux de reconstitution pérennisant cette ressource. Leur gestion durable exige notamment le développement et le respect de mesures d’aménagement pour rendre leur exploitation renouvelable à long terme. Cette exploitation doit s’appuyer sur une gestion adéquate des peuplements naturels et sur le reboisement ainsi que sur des mesures de conservation. Les recherches à développer doivent intéresser leur vitesse de croissance face aux évolutions climatiques, l’évaluation de leurs stocks (production, biomasse, carbone), l’actualisation de leur distribution spatiale, l’amélioration de leur régénération naturelle, les processus de leur reproduction, leurs propriétés anatomiques et technologiques, autant de pistes pertinentes pour garantir la pérennité des espèces exploitables du genre Entandrophragma. 

scholarly journals Remains of Leatherback turtles, Dermochelys coriacea, at Mid-Late Holocene archaeological sites in coastal Oman: clues of past worlds

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6123
Author(s):  
John G. Frazier ◽  
Valentina Azzarà ◽  
Olivia Munoz ◽  
Lapo Gianni Marcucci ◽  
Emilie Badel ◽  
...  
Keyword(s):  
Late Holocene ◽  
Chelonia Mydas ◽  
Dermochelys Coriacea ◽  
Resource Exploitation ◽  
Leatherback Turtles ◽  
Turtle Species ◽  
Marine Turtles ◽  
Exploitation And Utilization ◽  
Intense Exploitation ◽  
Human Burials

Small, irregular isolated bones identified as remains of leatherback turtles (Dermochelys coriacea) were recovered from Mid to Late Holocene sites at Ra’s al-Hamra and Ra’s al-Hadd, coastal Oman. These provide the third instance of this animal being documented from any prehistoric site anywhere, and the records provide one of the oldest, if not the oldest, dates for this distinctive chelonian—even though they do not refer to fossils. Decades of research in this region has yielded vast amounts of archeological information, including abundant evidence of intense exploitation and utilization of marine turtles from about 6,500 to 4,000 BP. During part of this period, turtle remains in human burials have been extraordinary; the turtle involved, Chelonia mydas, has been abundant in the region during modern times. Yet despite intense and varied forms of prehistoric marine resource exploitation, and major, long-term archeological work, no other turtle species has been previously authenticated from these, or other coastal sites. The documentation of remains of the largest and most distinctive of living marine turtles, D. coriacea, at Ra’s al-Hamra and Ra’s al-Hadd, presented herein, provide detailed information that serves as the basis for future interpretations and discussions regarding incomplete, disarticulated remains from the Mid to Late Holocene, particularly in reference to taphonomic questions and diverse environmental conditions.

scholarly journals Public Law Restrictions in the Context of 3D Land Administration—Review on Legal and Technical Approaches

Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 88
Author(s):  
Dimitrios Kitsakis ◽  
Eftychia Kalogianni ◽  
Efi Dimopoulou
Keyword(s):  
Property Rights ◽  
Public Law ◽  
Archaeological Sites ◽  
Real Property ◽  
Spatial Unit ◽  
3D Space ◽  
Land Administration ◽  
Utility Network ◽  
Intense Exploitation ◽  
Land Administration Systems

Intense exploitation of land implies the development of multi-level, multi-purpose, overlapping and interlocking structures on 3D space, thus resulting in complex, stratified, 3D real property rights between individual owners, as well as restrictions. Legislation regulates the ownership status and use of land by imposing restrictions known as Public Law Restrictions (PLRs). PLRs extend to various fields and various legislative frameworks, such as the protection of archaeological sites, protection and maintenance of underground infrastructures and utilities, environmental protection, flying of unmanned air vehicles, etc. PLRs are usually investigated in the context of property rights and restrictions in the various Land Administration Systems worldwide, and do not often gain specific attention. However, it is noticed that the restrictions that arise from Public Law need to be investigated and classified, so that they can be better utilised in the property status of land ownership. This review paper investigates the legal statutes on PLRs within the context of 3D land administration and the stipulations used to provide unambiguous modelling of PLRs, as provided by the relative literature. Moreover, the PLRs applied in the 3D space, to clearly depict rights, restrictions and responsibilities on the relevant spatial unit (land, air, marine parcel, mine, utility network, etc.), are particularly examined. Therefore, this work is to critically review and assess the aforementioned approaches on PLRs’ registration, modelling and organisation, as provided by a literature survey, and provides an overall view of the requirements and challenges within the development of 3D Land Administration Systems also considering standardisation developments.

scholarly journals Specialization and generalization in the diversification of phytophagous insects: tests of the musical chairs and oscillation hypotheses

2014 ◽  
Vol 281 (1795) ◽  
pp. 20132960 ◽  
Author(s):  
Nate B. Hardy ◽  
Sarah P. Otto
Keyword(s):  
Host Plant ◽  
Niche Breadth ◽  
Negative Relationship ◽  
Model System ◽  
Comparative Approach ◽  
Phytophagous Insects ◽  
Insect Herbivores ◽  
Plant Feeding ◽  
Intense Exploitation ◽  
Daughter Species

Evolutionary biologists have often assumed that ecological generalism comes at the expense of less intense exploitation of specific resources and that this trade-off will promote the evolution of ecologically specialized daughter species. Using a phylogenetic comparative approach with butterflies as a model system, we test hypotheses that incorporate changes in niche breadth and location into explanations of the taxonomic diversification of insect herbivores. Specifically, we compare the oscillation hypothesis, where speciation is driven by host-plant generalists giving rise to specialist daughter species, to the musical chairs hypothesis, where speciation is driven by host-plant switching, without changes in niche breadth. Contrary to the predictions of the oscillation hypothesis, we recover a negative relationship between host-plant breadth and diversification rate and find that changes in host breadth are seldom coupled to speciation events. By contrast, we present evidence for a positive relationship between rates of host switching and butterfly diversification, consonant with the musical chairs hypothesis. These results suggest that the costs of trophic generalism in plant-feeding insects may have been overvalued and that transitions from generalists to ecological specialists may not be an important driver of speciation in general.

Historical Review of the Management Approach to Exploitation and Introduction in SCOL Lakes

1972 ◽  
Vol 29 (6) ◽  
pp. 683-692 ◽  
Author(s):  
Henry A. Regier ◽  
Vernon C. Applegate
Keyword(s):  
Native Species ◽  
Historical Review ◽  
Management Approach ◽  
Reproductive Process ◽  
Conservation Movement ◽  
Artificial Propagation ◽  
Fisheries Resources ◽  
Technological Advances ◽  
Intense Exploitation ◽  
Hatchery Program

Though environmental deterioration and destruction has always concerned fishery biologists, much of their scientific and technical activities have been related to understanding and managing direct fisheries harvests, to "improving" fisheries resources through introductions of non-native species, and to assisting the reproductive process of valued stocks with a hatchery program. The history of these approaches in western countries is sketched by time periods as follows: pre-1840, gradually developing science and technology with intensifying direct exploitation; 1840–70, human food shortages in Europe, spreading of artificial propagation and development of hatchery and stocking techniques; 1870–1900, extensive introductions of non-native species, intensified exploitation because of technological advances and market forces, great expansion of artificial propagation; 1900–45, fluctuation in exploitation partly related to the socioeconomic aspects of world wars; 1945–60, conventional hatcheries closing, new fishing gear technology, more intense exploitation, growing concerns about pollution and eutrophication; 1960–70, "back to conservation" movement.

Female American lobster (Homarus americanus) size-at-maturity declined in Canada during the 20th and early 21st centuries

2018 ◽  
Vol 75 (6) ◽  
pp. 908-924 ◽  
Author(s):  
Marthe Larsen Haarr ◽  
Bernard Sainte-Marie ◽  
Michel Comeau ◽  
M. John Tremblay ◽  
Rémy Rochette
Keyword(s):  
Egg Production ◽  
Homarus Americanus ◽  
American Lobster ◽  
Past Century ◽  
Female Size ◽  
Strongly Correlated ◽  
Size At Maturity ◽  
The Past ◽  
Evolutionary Response ◽  
Intense Exploitation

Changes in the environment and fishing have been shown to affect life-history characteristics, such as size or age of maturation, in a number of finfish and invertebrates. The American lobster (Homarus americanus) supports Canada’s most valuable fishery and exploitation rates are high. Female size-at-maturity (SM) is an important parameter in management of this species, as it is used in establishing minimum legal size regulations. In this study, we show with historical and recent data that SM of female American lobsters has declined across most of Canada, in some areas by as much as 30%, over the past 10–80 years. The spatial patterns of these declines are inconsistent with patterns of rising ocean temperature and lobster abundance (density). They are, however, strongly correlated to the strength of size-based fishery selection, and egg-per-recruit modeling indicates a gain in lifetime egg production associated with observed SM declines under a range of realistic harvesting scenarios. These findings suggest that the marked decrease we document in SM of female American lobsters in Canada over the past century represents an evolutionary response to intense exploitation.

scholarly journals Changes in coyote activity patterns due to reduced exposure to human persecution

2000 ◽  
Vol 78 (5) ◽  
pp. 853-857 ◽  
Author(s):  
Ann M Kitchen ◽  
Eric M Gese ◽  
Edward R Schauster
Keyword(s):  
Field Study ◽  
Prey Availability ◽  
Average Rate ◽  
Activity Patterns ◽  
Field Studies ◽  
Number Of Factors ◽  
Significant Difference ◽  
Direct Form ◽  
Diurnal Movement ◽  
Intense Exploitation

Activity patterns in animals are influenced by a number of factors, including the animal's physiological adaptations, prey availability and distribution, and disturbances caused by predators and humans. We compared coyote (Canis latrans) activity patterns estimated using radio-tracking locations between 1983 and 1988 with those documented between 1996 and 1997 on the Pinon Canyon Maneuver Site, in southeastern Colorado. We tested the hypothesis that changes in the type of disturbance experienced by coyotes would result in changes in their activity patterns. Disturbance experienced by the coyote population studied during 1983-1988, included >50 years of intense exploitation (shooting and trapping by ranchers) and intensive removal efforts using aerial gunning. In contrast, coyotes tracked during 1996-1997 experienced some periodic disturbance from army maneuvers occurring in the area, but were not exposed to any direct form of persecution (e.g., shooting). From August 1983 to July 1988, 49 coyotes (26 males and 23 females) were tracked for >2400 h using radiotelemetry. From April 1996 to August 1997, 22 coyotes (12 males and 10 females) were tracked for >950 h. The average rate of diurnal movement of the coyotes in the 1996-1997 field study (mean = 0.97 km/h) was significantly higher than that of the coyotes in the 1983-1988 field study (mean = 0.68 km/h). This occurred despite no significant increase in the overall (24 h) rate of movement between the two field studies. Estimates of prey use by the coyotes in both field studies were obtained, to test an alternate hypothesis that prey switching might explain the changes in coyote movement patterns. However, there was no significant difference between the frequency of occurrence of diurnally versus nocturnally active mammalian prey species in the diets of coyotes in any season or overall between the 1983-1988 and 1996-1997 field studies. This study demonstrated that coyote activity patterns can be influenced by the type of disturbance experienced by the animal. A coyote population that had historically been exposed to human persecution shifted to higher levels of diurnal activity when exploitation ceased.

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