scholarly journals Prescriptions For The Control Of A Clonal Invasive Species Using Demographic Models

2021 ◽  
Author(s):  
Gabriel Arroyo Cosultchi ◽  
Jordan Golubov ◽  
Jonathan V Solórzano ◽  
María del Carmen Mandujano
Keyword(s):  
Invasive Species ◽  
Population Dynamics ◽  
Water Availability ◽  
Population Increase ◽  
Central Mexico ◽  
Management Scenarios ◽  
Finite Rate ◽  
Integral Projection ◽  
Demographic Models ◽  
Herbicide Treatments

Until recently, little focus has been given to determine the population dynamics of invasive species and evaluate their genetic variation. Consequently, not much is known of what drives clonal invasive species and their demography. Here we describe the population dynamics of Kalanchoe delagoensis (Crassulaceae), considered invasive to several countries. We quantified the demography of a population in central Mexico using integral projection models (IPM) in a population that reproduced asexually exclusively through plantlets. The effect of clonal recruitment on λ was evaluated by changing plantlet survival and simulating management scenarios that used previous data of watering and seven experimental herbicide treatments. The finite rate of population increase indicated that this Kalanchoe delagoensis population is growing (above one) with significant potential increases that correlated with water availability. The IPM showed that plantlet survival and recruitment were the most critical steps in the cycle for the population and simulations of different management scenarios showed that reducing plantlet survival significantly decreased λ only in two out of the seven herbicides used.

scholarly journals Demographic effects of interacting species: exploring stable coexistence under increased climatic variability in a semiarid shrub community

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana I. García-Cervigón ◽  
Pedro F. Quintana-Ascencio ◽  
Adrián Escudero ◽  
Merari E. Ferrer-Cervantes ◽  
Ana M. Sánchez ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Species Coexistence ◽  
Climatic Factors ◽  
Demographic Data ◽  
Climatic Variability ◽  
Biotic Interactions ◽  
Vital Rates ◽  
Climatic Fluctuations ◽  
Demographic Models ◽  
Shrub Community

AbstractPopulation persistence is strongly determined by climatic variability. Changes in the patterns of climatic events linked to global warming may alter population dynamics, but their effects may be strongly modulated by biotic interactions. Plant populations interact with each other in such a way that responses to climate of a single population may impact the dynamics of the whole community. In this study, we assess how climate variability affects persistence and coexistence of two dominant plant species in a semiarid shrub community on gypsum soils. We use 9 years of demographic data to parameterize demographic models and to simulate population dynamics under different climatic and ecological scenarios. We observe that populations of both coexisting species may respond to common climatic fluctuations both similarly and in idiosyncratic ways, depending on the yearly combination of climatic factors. Biotic interactions (both within and among species) modulate some of their vital rates, but their effects on population dynamics highly depend on climatic fluctuations. Our results indicate that increased levels of climatic variability may alter interspecific relationships. These alterations might potentially affect species coexistence, disrupting competitive hierarchies and ultimately leading to abrupt changes in community composition.

scholarly journals Long Term Interactions of Native and Invasive Species in a Marine Protected Area Suggest Complex Cascading Effects Challenging Conservation Outcomes

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 71
Author(s):  
Charalampos Dimitriadis ◽  
Ivoni Fournari-Konstantinidou ◽  
Laurent Sourbès ◽  
Drosos Koutsoubas ◽  
Stelios Katsanevakis
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
High Performance ◽  
Marine Protected Area ◽  
Habitat Degradation ◽  
Population Increase ◽  
Rocky Reef ◽  
Cascading Effects ◽  
High Level

Understanding the interactions among invasive species, native species and marine protected areas (MPAs), and the long-term regime shifts in MPAs is receiving increased attention, since biological invasions can alter the structure and functioning of the protected ecosystems and challenge conservation efforts. Here we found evidence of marked modifications in the rocky reef associated biota in a Mediterranean MPA from 2009 to 2019 through visual census surveys, due to the presence of invasive species altering the structure of the ecosystem and triggering complex cascading effects on the long term. Low levels of the populations of native high-level predators were accompanied by the population increase and high performance of both native and invasive fish herbivores. Subsequently the overgrazing and habitat degradation resulted in cascading effects towards the diminishing of the native and invasive invertebrate grazers and omnivorous benthic species. Our study represents a good showcase of how invasive species can coexist or exclude native biota and at the same time regulate or out-compete other established invaders and native species.

Population dynamics of large and small mammals: Graeme Caughley's grand vision

2009 ◽  
Vol 36 (1) ◽  
pp. 1 ◽  
Author(s):  
Charles J. Krebs
Keyword(s):  
Population Dynamics ◽  
Population Control ◽  
Population Increase ◽  
Control Mechanisms ◽  
Relative Role ◽  
Top Down ◽  
Large Herbivores ◽  
Disturbed Systems ◽  
Herbivorous Mammals ◽  
Grand Vision

Ecologists that study the population dynamics of large and small herbivorous mammals operate in two worlds that overlap only partly, and in this paper I address whether the conjecture that these worlds represent two distinct and valid paradigms is currently justified. I argue that large mammals fall into three groups depending on whether they have effective predators or not, and whether they are harvested by humans. Because of human persecution of large predators, more and more large herbivorous mammals are effectively predator-free and are controlled bottom-up by food. But in less disturbed systems, large herbivorous mammals should be controlled top-down by effective predators, and this can lead to a trophic cascade. Small herbivorous mammals have been suggested to be controlled top-down by predators but some experimental evidence has challenged this idea and replaced it with the notion that predation is one of several factors that may affect rates of population increase. Intrinsic control (territoriality, infanticide, social inhibition of breeding) appears to be common in small herbivorous mammals with altricial young but is absent in species with precocial young, in ecosystems with strong stochastic weather variation (deserts) and in areas of human-induced habitat fragmentation in agricultural monocultures. The extrinsic control of large herbivores with precocial young validates part of Graeme Caughley’s Grand Vision, but the relative role of intrinsic and extrinsic mechanisms for small herbivores with altricial young is still controversial. An improved knowledge of population control mechanisms for large and small herbivores is essential for natural resource management.

scholarly journals Population dynamics of spotted wing drosophila (Drosophila suzukii) in orchards in the Zagreb area

2020 ◽  
Vol 23 (3-4) ◽  
pp. 91-102
Author(s):  
Ivana Pajač Živković ◽  
Irena Brlić Puškarić ◽  
Darija Lemić
Keyword(s):  
Invasive Species ◽  
Population Dynamics ◽  
Overlapping Generations ◽  
Host Plants ◽  
Climatic Conditions ◽  
Spotted Wing Drosophila ◽  
Drosophila Suzukii ◽  
Research Population ◽  
Zagreb Area ◽  
The City

The invasive species Drosophila suzukii (Matsumura, 1931), the spotted wing drosophila, was first recorded in Croatia in 2010. Since then, it has spread on Croatian territory but its presence has not yet been confirmed in the City of Zagreb. In this research population dynamics of D. suzukii was investigated in three orchards in Zagreb (Maksimir, Jelenovac, Zelenjak) in the period from 20th of March to 27th of November 2017. Feeding traps with apple vinegar were used for catching D. suzukii. The flight began in the period from 27th of June to 11th of July and lasted until 27th of November. The total pest catches were 874 specimens (Jelenovac 187, Maksimir 232 and Zelenjak 455). From September to November there was a continuous flight and a large increase in the number of caught flies, suggesting the presence of more overlapping generations. Besides the host plants, the development of the pest in this area is also enabled by suitable climatic conditions. The present population in the City of Zagreb County poses a danger to fruit producers in the Zagreb County. The results of this research are a contribution to better understanding of the population and the spread of the pest in Croatia.

scholarly journals Population dynamics of five riverbed breeding bird species on the lower Drava River, NE Slovenia

Acrocephalus ◽  
2017 ◽  
Vol 38 (174-175) ◽  
pp. 85-126
Author(s):  
Luka Božič ◽  
Damijan Denac
Keyword(s):  
Population Dynamics ◽  
Bird Species ◽  
Breeding Population ◽  
Population Increase ◽  
General Situation ◽  
Breeding Bird ◽  
Main River Channel ◽  
Extreme Flood ◽  
Gravel Bars ◽  
Gravel Bar

AbstractIn 2006–2017, annual censuses of breeding bird species regarded as indicators of natural rivers were carried out on the 38.9 km long lowland stretch of the Drava riverbed between Maribor and Zavrč with altered flow regime due to the operating hydropower plants. Gravel bar habitats were surveyed in four years of the study period by combining orthophoto analysis and analysis of field photographs. Effects of gravel bar management were evaluated based at 20 locations. The Little Ringed PloverCharadrius dubiusoccurred on 39.8% of the gravel bars, but most were occupied only in a few years and held just one breeding pair. Low numbers between 2009 and 2012 (< 30 pairs) were followed by a steep population increase from 2014 onwards to a maximum of 66–73 pairs (1.7–1.9 p/km). Such population dynamics was attributed to the lack of large discharges (>500 m3/s) and consequent overgrowing of riverbed in the first part of the study period, while the increase in the second part was due to the creation of extensive shingle areas (from 20,6 ha in 2009/10 to 37,8 ha in 2014) by the extreme flood in early November 2012, subsequent regular occurrence of large discharges outside the breeding seasons and large-scale removals of woody vegetation. Breeding population of Common SandpiperActitis hypoleucosremained at a rather similar low level (<20 p) during most of the period studied after an initial decline, and did not reflect changes in the overall surface area of riverbed habitats. Contrary to the general situation, the number of breeding pairs on gravel bars subjected to management increased several-fold. Maximum number of pairs on these bars was reached up to four years after the initiation of management measures, as only then the optimal mosaic of early successional stages interspersed with shingle areas developed at main sites. The species was widespread only on lower part of the Drava. KingfisherAlcedo atthiswas fairly widely distributed along the riverbed, but occurred in rather low densities throughout (c. one pair on 2–3 km of the studied riverbed on average), probably as a result of limited bank erosion and consequent overgrowing/lack of suitable nest sites. The population was estimated as stable with effects of harsh winter conditions on breeding numbers in some years. The majority of nest holes were excavated in eroded river banks along the main river channel (77.8%), followed by similar sites located in mouth areas of small tributaries of the Drava (14.8%). Regular breeding of Sand MartinRiparia ripariasince 2012 (up to 259, mostly at only one location annually) was almost exclusively the result of the annual artificial nest site preparation programme. Fairly large gravel bar-breeding population of White WagtailMotacilla alba, monitored since 2013 and predominantly ground nesting in sparsely vegetated areas, seems unusual considering the prevalent breeding habits of the species at the European scale. Conservation implications and guidelines for future management efforts are discussed.

scholarly journals Integrating local social-ecological knowledge to prioritise invasive species management

2018 ◽  
Author(s):  
Hernán Cáceres-Escobar ◽  
Katrina J Davis ◽  
Scott C Atkinson ◽  
Hugh P Possingham ◽  
Salit Kark
Keyword(s):  
Invasive Species ◽  
Local Knowledge ◽  
Management Strategies ◽  
Well Being ◽  
Local Economy ◽  
Ecological Knowledge ◽  
Invasive Species Management ◽  
Management Scenarios ◽  
Red Foxes ◽  
Species Management

There is a lot of uncertainty about how we pick the best invasive species management strategies to improve the environment, local economy, and human well-being, as invasive species management involves complex and multidimensional challenges. Invasive species management on inhabited islands is especially challenging, often due to perceived socio-political risks and unexpected technical difficulties. Failing to incorporate local knowledge and local perspectives in the early stages of planning can compromise the ability of decision-makers to achieve long-lasting conservation outcomes. Hence, including local knowledge and accounting for subjective stakeholder perceptions is essential for invasive species management, yet this often remains unaddressed. To address this gap, we present an application of invasive species management based on structured decision-making, and the resource allocation tool INFFER, on Minjerribah-North Stradbroke Island (Australia). We assessed the cost-effectiveness of six management scenarios, co-developed with local land managers and community groups, aimed at preserving the environmental and cultural significance of the island by eradicating European red foxes and feral cats. We further conducted a survey eliciting local stakeholders’ perspectives regarding the significance of the Island, their perception of the benefits of the proposed management scenarios, funding requirements, technical feasibility of implementation, and socio-political risk. We found that the best decisions when the budget is low are less cost-effective than when the budget is high. The best strategy focusses on control of European red fox on Minjerribah. However, our results also highlight the need for more research on feral cat management. This work demonstrates how to use a structured decision support tool, like INFFER, to assess contesting management strategies, this is particularly important when stakeholders’ perceptions regarding management outcomes are heterogeneous and uncertain.

Integral projection models

2021 ◽  
pp. 181-196
Author(s):  
Edgar J. González ◽  
Dylan Z. Childs ◽  
Pedro F. Quintana-Ascencio ◽  
Roberto Salguero-Gómez
Keyword(s):  
Population Dynamics ◽  
Environmental Variables ◽  
Linear Models ◽  
Vital Rates ◽  
Matrix Population Models ◽  
Generalised Linear Models ◽  
Integral Projection Models ◽  
Integral Projection ◽  
Over Time

Integral projection models (IPMs) allow projecting the behaviour of a population over time using information on the vital processes of individuals, their state, and that of the environment they inhabit. As with matrix population models (MPMs), time is treated as a discrete variable, but in IPMs, state and environmental variables are continuous and are related to the vital rates via generalised linear models. Vital rates in turn integrate into the population dynamics in a mechanistic way. This chapter provides a brief description of the logic behind IPMs and their construction, and, because they share many of the analyses developed for MPMs, it only emphasises how perturbation analyses can be performed with respect to different model elements. The chapter exemplifies the construction of a simple and a more complex IPM structure with an animal and a plant case study, respectively. Finally, inverse modelling in IPMs is presented, a method that allows population projection when some vital rates are not observed.

Biotic interactions and the population dynamics of the long-lived columnar cactus Neobuxbaumia tetetzo in the Tehuacán Valley, Mexico

1999 ◽  
Vol 77 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Héctor Godínez-Alvarez ◽  
Alfonso Valiente-Banuet ◽  
Leopoldo Valiente Banuet
Keyword(s):  
Population Dynamics ◽  
Matrix Models ◽  
Biotic Interactions ◽  
Positive Interactions ◽  
Elasticity Analysis ◽  
Finite Rate ◽  
Tehuacán Valley ◽  
Columnar Cactus ◽  
Tehuacan Valley ◽  
Rate Of Increase

The giant columnar cactus Neobuxbaumia tetetzo (Coulter) Backeberg is the dominant species of a vegetation type locally called "tetechera" that occupies ca. 400 km2 in the Tehuacán Valley. As a way to analyse the role of biotic interactions on the population dynamics of this species, we conducted an elasticity analysis, using matrix models elaborated from field data, to determine the finite rate of increase and the critical stages of the life cycle that were related to the biotic interactions occurring during these stages. Although the estimated finite rate of increase did not differ from unity there were significant differences between the actual and predicted size distributions. Elasticity analysis showed that survivorship was the most important life-history parameter to the finite rate of increase. Because survivorship depends on the presence of nurse plants, our results emphasise the importance of positive interactions on the population dynamics of long-lived columnar cacti.Key words: biotic interactions, Cactaceae, deserts, matrix models, population dynamics.

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