scholarly journals Patterns in individual growth, branch population dynamics, and growth and mortality of first-order branches of Betula platyphylla in northern Japan

2000 ◽  
Vol 57 (5) ◽  
pp. 587-598 ◽  
Author(s):  
Kiyoshi Umekia ◽  
Kihachiro Kikuzawa
Keyword(s):  
Population Dynamics ◽  
Individual Growth ◽  
Betula Platyphylla ◽  
First Order ◽  
Northern Japan

scholarly journals Population parameters and the relationships between environmental factors and abundance of the Acetes americanus shrimp (Dendrobranchiata: Sergestidae) near a coastal upwelling region of Brazil

2015 ◽  
Vol 63 (3) ◽  
pp. 229-238
Author(s):  
Ana Paula Freitas dos Santos ◽  
Sabrina Morilhas Simões ◽  
Gabriel Lucas Bochini ◽  
Cinthia Helena Costa ◽  
Rogerio Caetano da Costa
Keyword(s):  
Population Dynamics ◽  
Sexual Dimorphism ◽  
Environmental Factors ◽  
Primary Productivity ◽  
Low Temperatures ◽  
Coastal Upwelling ◽  
Statistical Correlation ◽  
Individual Growth ◽  
Otter Trawl ◽  
Population Parameters

AbstractThe population dynamics of Acetes americanus was investigated, focusing on the sex ratio, individual growth, longevity, recruitment and relationship between abundance and environmental factors in the region of Macaé, strongly influenced by coastal upwelling. Otter trawl net samplings were performed from July 2010 to June 2011 at two points (5 m and 15 m). Nearly 19,500 specimens, predominantly females (77.15%), were captured. Their sizes, larger than that of males, indicated sexual dimorphism. Shrimps at lower latitudes present larger sizes and longer longevity than those from higher latitudes. This difference is probably due to low temperatures and high primary productivity. Though no statistical correlation was found between abundance and environmental factors, the species was more abundant in temperatures closer to 20.0º C and in months with high chlorophyll-a levels. Due to the peculiar characteristics of this region, A. americanusshowed greater differences in size and longevity than individuals sampled in other studies undertaken in the continental shelf of Southeast Brazil.

scholarly journals Seasonal dynamics of <I>Pseudocalanus minutus elongatus</I> and <I>Acartia spp.</I> in the southern Baltic Sea (Gdańsk Deep) – numerical simulations

2006 ◽  
Vol 3 (4) ◽  
pp. 1157-1202
Author(s):  
L. Dzierzbicka-Głowacka ◽  
L. Bielecka ◽  
S. Mudrak
Keyword(s):  
Population Dynamics ◽  
Baltic Sea ◽  
Seasonal Dynamics ◽  
Egg Production ◽  
Phytoplankton Bloom ◽  
Individual Growth ◽  
Initial Development ◽  
Southern Baltic Sea ◽  
Gdansk Deep ◽  
Southern Baltic

Abstract. A population dynamics model for copepods is presented describing a seasonal dynamics of Pseudocalanus minutus elongatus and Acartia spp. in the southern Baltic Sea (Gdansk Deep). The copepod model was coupled with an one-dimensional physical and biological upper layer model for nutrients (total inorganic nitrogen, phosphate), phytoplankton, microzooplankton and an early juvenile of herring as predator. In this model, mesozooplankton (herbivorous copepods) has been introduced as animals having definite patterns of growth in successive stages, reproduction and mortality. The populations are represented by 6 cohorts in different developmental stages, thus assuming, that recruitment of the next generation occurs after a fixed period of adult life. The copepod model links trophic processes and population dynamics, and simulates individual growth within cohorts and the changes in biomass between cohorts. The simulations of annual cycles of copepods contain one complete generation of Pseudocalanus and two generations of Acartia in the whole column water, and indicate the importance of growth of older stages of 6 cohorts each species to total population biomass. The peaks of copepods biomass, main, at the turn of June and July for Pseudocalanus and smaller, in July for Acartia, lag that phytoplankton by ca. two mouths due to growth of cohorts in successive stages and egg production by females. The numerical results show that the investigated species could not be the main factor limiting the spring phytoplankton bloom in the Gdansk Deep, because the initial development was slow for Acartia and faster for Pseudocalanus, but main development formed after the bloom, in both cases. However, the simulated microzooplankton biomass was enough high to conclude, in our opinion, that, in this case, it was major cause limiting phytoplankton bloom. Model presented here is a next step in understanding how the population dynamics of a dominant species in the southern Baltic Sea interact with the environment.

scholarly journals Fine root turnover of Japanese white birch (Betula platyphylla var. japonica) grown under elevated CO2 in northern Japan

Trees ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 363-374 ◽  
Author(s):  
Xiaona Wang ◽  
Saki Fujita ◽  
Tatsuro Nakaji ◽  
Makoto Watanabe ◽  
Fuyuki Satoh ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Fine Root ◽  
Root Turnover ◽  
Betula Platyphylla ◽  
White Birch ◽  
Fine Root Turnover ◽  
Northern Japan

scholarly journals Tree Regeneration Patterns on Contrasting Slopes at Treeline Ecotones in Eastern Tibet

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1605
Author(s):  
Lili Zheng ◽  
Peili Shi ◽  
Tiancai Zhou ◽  
Ge Hou ◽  
Minghua Song ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Empirical Studies ◽  
Tree Regeneration ◽  
Individual Growth ◽  
Growth And Survival ◽  
Alpine Treeline ◽  
The North ◽  
Adult Trees ◽  
The Individual

Alpine treelines are projected to shift upslope in response to climate warming, but empirical studies have yielded inconsistent results, with both upshifted and stable alpine treelines. Additionally, treelines on different slope aspects of the same mountain can differ. Thus, for a better understanding of the mechanisms of treeline formation and treeline responses to climate change, we need to elucidate the population dynamics at treelines on different slope aspects. Here, we quantified the population dynamics of Balfour spruce (Picea likiangensis var. rubescens) at treeline ecotones on contrasting north- and east-facing slopes on the eastern Tibetan Plateau based on field surveys. The alpine treeline positions of Balfour spruce have not advanced toward higher altitudes on the contrasting slopes in recent decades. Compared with the east-facing slope, more recruits occurred on the north-facing slope above the present treeline, indicating a more favorable regeneration condition. However, on the north-facing slope, the individual growth rate of Balfour spruce was lower, and the number of adult trees above the present treeline was higher than that on the east-facing slope. Thus, slope aspects mediate a trade-off between the growth and survival of treeline species, explaining the absence of an impact of slope aspects on treeline responses to climate change. Our results highlight the importance of considering the effect of topography on population dynamics in predicting alpine treeline dynamics under the scenario of climate change.

Assessing the production and the impact of cultivated oysters in the Thau lagoon (Mediterranee, France) with a population dynamics model

2001 ◽  
Vol 58 (5) ◽  
pp. 1012-1020 ◽  
Author(s):  
A Gangnery ◽  
C Bacher ◽  
D Buestel
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Standing Stock ◽  
Individual Growth ◽  
Economic Activities ◽  
Daily Growth ◽  
Mediterranean Mussel ◽  
Thau Lagoon ◽  
The Individual ◽  
The Impact

The Thau lagoon (France) has been studied for many years because of its ecological interest related to economic activities: shellfish cultivation, tourism, and industry. The standing stock of cultivated filter feeders is around 20 000 t and consists of two main species, the Japanese oyster Crassostrea gigas and the Mediterranean mussel Mytilus galloprovincialis. To predict changes in the standing stock and the annual production, a mathematical model of the population dynamics was defined. It was based on the continuous equation of the density as a function of the mortality rate, the individual growth rate, and the interindividual variability. The daily growth rate was derived from field surveys and depended on the phytoplankton concentration and individual weight. The model also took into account the rearing strategy of the producers defined by the timetable of seeding and harvesting, obtained by an inquiry among the producers and used to simulate real cases of standing stock changes. The model was also used to assess the potential impact on the environment through the computation of the food consumption, which was compared with the residence time and the primary production.

scholarly journals Effects of species invasion on population dynamics, vital rates, and life histories of the native species

2017 ◽  
Author(s):  
Simone Vincenzi ◽  
Alain J Crivelli ◽  
Dusan Jesensek ◽  
Ellen Campbell ◽  
John C Garza
Keyword(s):  
Population Dynamics ◽  
Rainbow Trout ◽  
Native Species ◽  
Life Histories ◽  
Life History Theory ◽  
Individual Growth ◽  
Growth Trajectories ◽  
Natural Environments ◽  
Vital Rates ◽  
Marble Trout

AbstractInvasions occurring in natural environments provide the opportunity to study how vital rates change and life histories evolve in the presence of a competing species. In this work, we estimate differences in reproductive traits, individual growth trajectories, survival, life histories, and population dynamics between a native species living in allopatry and in sympatry with an invasive species of the same taxonomic Family. We used as a model system marble trout Salmo marmoratus (native species) and rainbow trout Oncorhynchus mykiss (non-native) living in the Idrijca River (Slovenia). An impassable waterfall separates the stream in two sectors only a few hundred meters apart: a downstream sector in which marble trout live in sympatry with rainbow trout and a upstream sector in which marble trout live in allopatry. We used an overarching modeling approach that uses tag-recapture and genetic data (> 2,500 unique marble and rainbow trout were sampled and SNP-genotyped) to reconstruct pedigrees, test for synchrony of population dynamics, and model survival and growth while accounting for individual heterogeneity in performance. The population dynamics of the two marble trout populations and of rainbow trout were overall synchronous. We found higher prevalence of younger parents, higher mortality, and lower population density in marble trout living in sympatry with rainbow trout than in marble trout living in allopatry. There were no differences in the average individual growth trajectories between the two marble trout populations. Faster life histories of marble trout living in sympatry with rainbow trout are consistent with predictions of life-history theory.

scholarly journals Degradation of White Birch Shelterbelts by the Attack of White-Spotted Longicorn Beetles in Central Hokkaido, Northern Japan

Forests ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 34
Author(s):  
Kazuhiko Masaka ◽  
Yohichi Wakita ◽  
Kenta Iwasaki ◽  
Masato Hayamizu
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Generalized Linear Mixed Model ◽  
Betula Platyphylla ◽  
White Birch ◽  
Size Dependent ◽  
Dead Trees ◽  
Standing Dead ◽  
Standing Dead Trees ◽  
Northern Japan

A widespread decline of white birch (Betula platyphylla var. japonica) shelterbelts was observed in central Hokkaido, Japan. Many exit holes bored by white-spotted longicorn beetles (Anoplophora malasiaca) were found at the base of the trunks of trees in these stands. The present study aims to evaluate the effects of infestation on the degradation, and demonstrates whether the number of exit holes (Nholes) can be used as an index of the decline of trees. We selected 35 healthy appearing stands and 16 degraded stands in the study area. A generalized linear mixed model with zero inflation revealed that Nholes of standing dead trees tended to be greater than that of living trees, and the tree vigor decreased with increasing Nholes. These results implied that the degradation of the shelterbelts was caused by the beetle. We also found size-dependent mortality, i.e., only a few larvae can cause the death of smaller trees, but not larger trees. Furthermore, evaluation of the degradation at the stand level (Nholes) using a logistic regression analysis revealed that the degradation at the stand level could be predicted by Nholes. Our findings can be used as a useful index marker for diagnosing white birch shelterbelts.

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