scholarly journals Demography of Attalea nucifera: Sustainable management and conservation of a threatened species of Colombia

Caldasia ◽  
2020 ◽  
Vol 42 (2) ◽  
pp. 313-325
Author(s):  
Jorge Prada-Ríos ◽  
Néstor García
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Sustainable Management ◽  
Matrix Population Model ◽  
Environmental Disturbances ◽  
Finite Growth ◽  
Demographic Processes ◽  
Extinction Threshold ◽  
Magdalena River ◽  
Management And Conservation

Attalea nucifera is an acaulescent palm native of Colombia that is in risk of extinction. Between 2016-2017 we evaluated the structure and density of populations in six localities of the Magdalena river valley, and studied the population dynamic in the locality of Guaduas, Cundinamarca (VC). Although the population structure differs among locations (X2 = 1819, gl = 25, P < 0.05), populations tend to group according to the degree of habitat perturbation. In four localities an inverted J population structure was observed. A matrix population model showed a finite growth rate (λ) of 0.979 (CI95 % = 0.962–0.997). The demographic processes of the permanence of seedlings, sub-adults and young adults show more elasticity. A transient dynamic simulation projected to 30 years shows that under the scenarios of paddock and cattle lopping the population size decrease drastically. The extinction threshold calculated for the population in the locality VC is of 145 years, but paddock and cattle lopping activities can reduce it to less than 40 years. Although Attalea nucifera persists in very disturbing locations in the Middle Magdalena Basin, the results of population dynamics in the locality VC suggest that it could be less tolerant of environmental disturbances. Thus, it is necessary to increase our knowledge of its population dynamics, as well as seed germination and seedling establishment in different disturbance conditions.

scholarly journals European lobster stocking requires comprehensive impact assessment to determine fishery benefits

2014 ◽  
Vol 72 (suppl_1) ◽  
pp. i35-i48 ◽  
Author(s):  
Charlie D. Ellis ◽  
David J. Hodgson ◽  
Carly L. Daniels ◽  
Dominic P. Boothroyd ◽  
R. Colin A. Bannister ◽  
...  
Keyword(s):  
Population Genetics ◽  
Population Dynamics ◽  
Population Structure ◽  
North America ◽  
Sustainable Management ◽  
Economic Benefits ◽  
Basic Knowledge ◽  
European Lobster ◽  
The Impact ◽  
Key Questions

Abstract Historically, hatcheries in Europe and North America attempted to contribute to the conservation and enhancement of clawed lobster stocks, but lacked monitoring programmes capable of assessing success. In the 1990s, this perspective was changed by the results of restocking and stock enhancement experiments that inserted microwire tags into hatchery-reared juvenile European lobsters (Homarus gammarus) before release. This allowed recapture in sufficient numbers to prove that lobsters had survived and recruited to the mature fishable stock. However, evidence of recruitment still failed to answer key questions about the ultimate ecological and economic benefits. As a result, a growing number of lobster stocking ventures remain hindered by a lack of clear evidence of the effects of their stocking schemes. This review evaluates these experiments and related studies on other fished species, summarizes key findings, and identifies data and knowledge gaps. Although studies of fitness in cultured lobsters provide some of the most encouraging results from the wider field of hatchery-based stocking, the limitations of physical tagging technology have significantly hindered appraisals of stocking impacts. We lack basic knowledge of lobster ecology and population dynamics, especially among prerecruits, and of the impact of stocking on wild lobster population genetics. We advocate the use of genetic methods to further our understanding of population structure, rearing processes, and stocking success. We also recommend that more focused and comprehensive impact assessments are required to provide a robust endorsement or rejection of stocking as a viable tool for the sustainable management of lobster fisheries.

scholarly journals Population dynamics in northwestern China

2021 ◽  
Author(s):  
Xueyan Yang ◽  
Wanxin Li ◽  
Wen Jing ◽  
Chezhuo Gao ◽  
Rui Li ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Population Size ◽  
Ethnic Groups ◽  
Northwestern China ◽  
Average Level ◽  
Han Population ◽  
Sex Structure ◽  
Biological Sex

AbstractThis article analyzes the population dynamics in northwestern China from roughly 2010 to 2020. The area’s dynamics showed a slow, stable increase in population size, a stable increase in the population of non-Han ethnic groups, which increased at a more rapidly than the Han population, and population rejuvenation coupled with a population structure that aged. The biological sex structure fluctuated within a balanced range in northwestern China. Urbanization advanced in northwestern China, throughout this period, but the area’s level of urbanization is still significantly lower than the average level of urbanization nationally.

scholarly journals POPULATION STRUCTURE AND PRODUCTION OF COPAIBA OLEORESIN BETWEEN VALLEYS AND HILLSIDES OF THE MINING AREA OFTROMBETAS RIVER - PARÁ1

2016 ◽  
Vol 40 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Jonas Gebara ◽  
Antenor Pereira Barbosa ◽  
Isabel Maria Gonçalves Azevedo ◽  
Bruno Oliva Gimenez
Keyword(s):  
Population Structure ◽  
Forest Inventory ◽  
Sustainable Management ◽  
Natural Populations ◽  
Mining Area ◽  
National Forest ◽  
The South ◽  
Potential Production ◽  
Average Value ◽  
Bauxite Ore

ABSTRACT We aimed in this work to study natural populations of copaiba (Copaifera multijuga Hayne) on the Monte Branco mountain at Porto Trombetas-PA, in order to support sustainable management and the exploitation of oleoresin from copaiba. We studied the population structure of copaiba on hillsides and valleys of the south face of Monte Branco, within Saracá Taquera National Forest, where bauxite ore was extracted in the biennium 2013-2014 by Mineração Rio do Norte (MRN). We produced a 100% forest inventory of the specie and of oleoresin extraction in order to quantify the potential production of the remaining area. The density of copaiba individuals with DBH > 30 cm was 0.33 individuals per hectare in the hillside and 0.25 individuals per hectare in the valley. Both environments presented a density of 0.28 individuals per hectare. The average copaiba oleoresin yield was 0.661±0.334 liters in the hillside and 0.765±0.280 liters in the valley. The average value of both environments together (hillside and valley) was 0.714±0.218 liters. From all individuals with DBH over 30 cm, 38 (58%) produced some amount of oleoresin, averaging 1.113±0.562 liters in the hillside, 1.329±0.448 liters in the valley and 1.190±0.355 liters in both environments together. The results show the need for planning the use of the surroundings of the study area in order to reach the required volume of copaiba to make feasible the sustainable management of oleoresin extraction in the region.

scholarly journals A Global Agenda for Advancing Freshwater Biodiversity Research

2021 ◽  
Author(s):  
Alain Maasri ◽  
Sonja Jähnig ◽  
Mihai Adamescu ◽  
Rita Adrian ◽  
Claudio Baigun ◽  
...  
Keyword(s):  
Sustainable Management ◽  
Freshwater Biodiversity ◽  
Biodiversity Crisis ◽  
Critical Step ◽  
Biodiversity Research ◽  
Coordinated Action ◽  
Global Agenda ◽  
Management And Conservation

Freshwater biodiversity is declining dramatically, and the current biodiversity crisis requires defining bold goals and mobilizing substantial resources to meet the challenges. While the reasons are varied, both research and conservation of freshwater biodiversity lag far behind efforts in the terrestrial and marine realms. We identify fifteen pressing global needs to support informed global freshwater biodiversity stewardship. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated action towards its sustainable management and conservation.

scholarly journals Population dynamics of mantis shrimp Harpiosquilla harpax and Oratosquillina sp. in the waters south of Madura Island, Indonesia

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Yenni Arista ◽  
ZAIRION ◽  
YUSLI WARDIATNO
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Life Span ◽  
Fishery Resource ◽  
Growth Coefficient ◽  
Mantis Shrimp ◽  
Exploitation Rate ◽  
L Value ◽  
Males And Females

Abstract. Ekalaturrahmah YAC, Zairon, Wardiatno Y. 2020. Population dynamics of mantis shrimp Harpiosquilla harpax and Oratosquillina sp. in the waters south of Madura Island, Indonesia. Biodiversitas 21: 1458-1466. Mantis shrimps are a potential fishery resource in Indonesia, but information about their population dynamics in the southern waters of Madura is limited. This study aimed to determine the population structure, growth, life span, and rate of exploitation for two taxa of mantis shrimp (Harpiosquilla harpax and Oratosquillina sp.). The research was conducted from September 2018 to February 2019 in the southern waters of Madura. The results showed that for H. harpax the majority of males caught ranged in length between 132.50 and 139.37 mm while the majority of females were between 153.45 and 160.22 mm. For Oratosquillina sp., the majority of males caught ranged from 84.70 and 89.60 mm while the majority of females were between 89.85 and 95.30 mm. The Growth Coefficient (K) for H. harpax was estimated to be 0.65 per year for males and 0.60 per year for females; while for Oratosquillina sp. the estimates were 0.81 and 0.78 per year, respectively. The L∞ value for H. harpax males was 183.00 mm and for females 250.55 mm, while the L∞ values for Oratosquillina sp. were 112.64 mm for males and 137.02 for females. The life span of H. harpax was estimated at 5 years, while for Oratosquillina sp. it was 4 years. The exploitation rate (E) for H. harpax males and females was 0.65 and 0.67 respectively, while for Oratosquillina sp. it was 0.54 and 0.58. These estimations indicated overexploitation of the resource, particularly in the case of H. harpax.

scholarly journals Length-weight Relationship, Growth Pattern and Condition Factor of the Silver Catfish Chrysichthys nigrodigitatus (Lacepède, 1803) from Lower River Benue, Nigeria

2018 ◽  
pp. 1-8
Author(s):  
Edem, Edem Thomas ◽  
Ofunama, Preye ◽  
Eyo, Victor `Oscar
Keyword(s):  
Population Dynamics ◽  
Growth Pattern ◽  
Sustainable Management ◽  
Condition Factor ◽  
B Value ◽  
Health Condition ◽  
Artisanal Fisheries ◽  
Allometric Growth ◽  
Silver Catfish ◽  
Weight Relationship

This study was carried out to evaluate the length-weight relationship, growth pattern and condition factor of the Silver catfish Chrysichthys nigrodigitatus from the Lower River Benue Makurdi, Nigeria. A total of 200 freshly caught specimens of C. nigrodigitatus were collected between July 2013 and September 2013 from the catches of the artisanal fisheries at landing points in Wadata Market, Makurdi. Results obtained showed that the “b” value for the males was 1.6067 while that of the females was 1.6791 and combined sexes 1.7371, indicating a negative allometric growth for this species. Correlation coefficient (r) obtained for males (0.9651), 0.9517 (females) and 0.9329 (pooled sexes) showed a positive significant relationship between length and weight of C. nigrodigitatus. Monthly mean condition factor (K), indicate that C. nigrodigitatus were in good physiological health condition. In conclusion, the baseline data on the length-weight relationship, condition factor of C. nigrodigitatus from the lower River Benue provided in this study is crucial in the sustainable management of this species in the River. Also, these findings will be useful in evaluating the population dynamics, stock and the aquaculture potential of C. nigrodigitatus for future purpose.

A temporal perspective on population structure and gene flow in Atlantic salmon (Salmo salar) in Newfoundland, Canada

2010 ◽  
Vol 67 (2) ◽  
pp. 225-242 ◽  
Author(s):  
Friso P. Palstra ◽  
Daniel E. Ruzzante
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Gene Flow ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Environmental Changes ◽  
Population Connectivity ◽  
Temporal Perspective ◽  
Atlantic Salmon Salmo Salar ◽  
Contemporary Gene Flow

Studying population structure and gene flow patterns on temporal scales facilitates an evaluation of the consequences of demographic, physical, and environmental changes on the stability and persistence of populations. Here, we examine temporal genetic variation within and among Atlantic salmon ( Salmo salar ) rivers in Newfoundland and Labrador, Canada, using samples collected over a period of six decades (1951–2004). Our objective was to evaluate temporal changes in population connectivity associated with the closure of a commercial marine fishery. Despite demographic instability, we find that population structure remained temporally stable over more than 50 years. However, age structure can affect results when not taken into consideration, particularly in populations of large effective size where genetic drift is not strong. Where weak signals of genetic differentiation did not complicate analyses, contemporary migration was often asymmetric, yet low, suggesting patterns of intermittent gene flow. Nevertheless, we find some links between changes in population dynamics and contemporary gene flow. These findings may therefore imply that management decisions impacting the contemporary population dynamics of individual Atlantic salmon rivers can also affect the genetic stability of this species as a whole.

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