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Population ecology of agroecosystems
Published in Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz, Agroecology, 2023
Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz
Each species that is successful in a particular environment has a unique set of adaptations, or traits, that allow it to maintain a population in that environment over time. Of these adaptations, those called life history traits directly contribute to an organism’s fitness. Life history traits can be divided into three main classes: age and size at maturity, number and size of offspring, and lifespan and reproductive investment. The combination of different life history traits (e.g., large size, long life span, and much investment in few offspring) can be thought of as a life history “strategy.” A strategy organizes the life cycle of a species to insure reproduction and the continuation of a viable population. Across species, life history strategies can be classified into general types.
Genetic Factors and Tolerance Acquisition in Populations Exposed to Metals and Metalloids
Published in Michael C. Newman, Alan W. McIntosh, Metal Ecotoxicology, 2020
Margaret Mulvey, Stephen A. Diamond
Klerks and Levinton29 suggest a “cost” of resistance to metals in oligochaetes; worms reared in clean sediment for two generations showed a decrease in resistance. The authors suggest that resistant individuals have a reduced fitness relative to nonresistant individuals in the clean environment. Similarly, embryonic tolerance is not without “cost” in Fundulus heteroclitus. Methylmercurytolerant embryos displayed reduced salinity and HgCl2 tolerance, slower growth, and weakness as adults.34 Toppin et al.38 reported that the response of F. heteroclitus to heavy metal stress involved changes in life history characteristics: fish from contaminated sites were smaller, reproduced at an earlier age, and had shorter life-spans. These shifts in life history characteristics suggested that the lifetime reproductive success of the impacted population might not be significantly different from that of a control population despite the higher mortality rate. In contrast, Duncan and Klaverkamp43 and Chapman44 report poor recruitment of young in white suckers shown to be metal tolerant. Chapman44 concluded that increased tolerance was sometimes associated with significant sublethal toxicity affecting the condition, growth, and reproduction of fishes. Such sublethal effects may only postpone population extinction. Alternatively, populations displaying sublethal effects may persist long enough for additional tolerance mechanisms to evolve.
Biological Factors Impeding Recovery of Predatory Fish Populations
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Biological and Ecological Systems, 2020
Factors impeding recovery of depleted fish populations can be numerous including biological, environmental and socioeconomic factors (Garcia et al. 2018). Some biological factors preventing a successful recovery of depleted fish stocks are altered ecological interactions and intrinsic characteristics of the populations, i.e., life history traits. Environmental factors include loss of habitat, in particular, coastal and coral reef degradation, as well as natural oscillations in climatic and productivity variables that condition the recruitment into the depleted stock (Friedland et al. 2009). Several socioeconomic factors have been identified to cause the failure of recovery of depleted fish stocks, for instance, the inability to find alternative livelihoods for fishermen after the depletion preventing fishing mortality to be reduced, social organization and cohesion that may facilitate compliance or illegal behavior (Wakeford et al. 2009). In this chapter, I will focus on the biological factors that impair recovery of depleted predatory fish populations in more detail.
Resting eggs of the perennial copepod Eodiaptomus japonicus in Lake Biwa (Japan)
Published in Inland Waters, 2020
Xin Liu, Syuhei Ban, Delphine Beyrend, Gaël Dur, Michinobu Kuwae, Wataru Makino, Jotaro Urabe
Previous studies demonstrated that copepods transferred to a new habitat continued to produce subitaneous or resting eggs according to their practice in their native habitat (Hairston and Olds 1984, Hairston and Olds 1987). The underlying rationale is that the phenotypic responses are inherited from the previous generation that adapted to a given type of environment, a phenomenon called “transgeneration effects,” in which mothers transmit information to their offspring that influences their life history traits (Alekseev and Lampert 2001). Hairston et al. (1985) showed transgeneration effects for Diaptomus sanguineus colonizing both permanent and temporary ponds in Rhode Island (USA) through reciprocal transferring experiments.
Modeling residential mobility decisions from a life history–oriented perspective
Published in Transportation Letters, 2022
Muntahith Mehadil Orvin, Mahmudur Rahman Fatmi
The contributions of this research are twofolds: i) adopting a life history–oriented approach to investigate the effects of life-cycle events on residential mobility decisions and ii) developing an advanced continuous-time hazard-based duration model to capture unobserved heterogeneity and accommodate the correlated sequence of repeated residential durations. Theory of life history focuses on the interdependencies among changes occurring along the life-course at different life domains such as residence, employment, family, neighborhood, and travel behavior (Chatterjee and Scheiner 2015; J Zhang et al. 2011; Junyi; Zhang and Acker 2017). Motivated by the findings of Clark (2013) and Rashidi (2015), this study explores how mobility is influenced by changes in several life domains including family domain such as birth of a child and death of a member, employment domain such as change of job and loss of job, and travel such as vehicle ownership, among others. The influence of the life-cycle events might vary across the dwellers in different sociodemographic, land use, and neighborhood settings. To capture the heterogeneity, this study develops an advanced hazard-based duration model, specifically a hazard-based latent segment duration (HLSD) model. One of the key features of this model is to capture heterogeneity by formulating a flexible segment allocation component within the HLSD modeling framework. The segment allocation model captures unobserved heterogeneity by distributing households into discrete latent segments. Furthermore, the HLSD model accommodates the effects of multiple residential spells – i.e. repeated duration at different residences along the life-course of the households. The model addresses such correlated sequence of repeated durations of the households. Finally, this study extensively tests the effects of life-cycle events, land use attributes, accessibility measures, neighborhood features, and sociodemographic characteristics.