scholarly journals Does the Genetic Diversity of Macuilillo, Oreopanax xalapensis (Araliaceae), Change Along Successional Gradients of the Montane Cloud Forest?

2019 ◽  
Vol 12 ◽  
pp. 194008291987292
Author(s):  
Farah Z. Vera-Maloof ◽  
Lorena Ruiz-Montoya ◽  
Neptalí Ramírez-Marcial
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Forest Succession ◽  
Cloud Forest ◽  
Conservation Strategies ◽  
Age Classes ◽  
Successional Stage ◽  
Montane Cloud Forest ◽  
Successional Species ◽  
Successional Stages

Forest regeneration after human-induced or natural disturbances results in a sequential replacement of species, starting with colonizing of pioneer species that modifies the physical conditions of the environment, which later allows the establishment of mid- and late-successional species. Whether the forest succession implies a reduction of population size of tree species might be expected a less genetic diversity in populations inhabiting oldest succession stages. We aimed to study whether genetic diversity of Macuilillo, Oreopanax xalapensis (a understory tree), decreases in advanced age-classes and in late successional of montane cloud forest at Huitepec Ecological Reserve (Chiapas, Mexico). We counted individuals from three age classes: seedlings, saplings, and young reproductive individuals in nine plots along three successional stages (early-, middle-, and late-successional forests). Seven enzyme systems (SOD, AP, FUM, G6PDH, GOT, GPI, and G3PDH) were used to obtain common genetic diversity; Φ-statistics and a Bayesian model were used to infer population structure. At the early-successional stage, O. xalapensis had a bigger population size and significantly high numbers of seedlings. In general, among the successional stages, the genetic diversity of O. xalapensis was moderate to high ( He = 0.25–0.46); the saplings presented the highest expected genetic diversity ( He). Populations were genetically structured by age-classes but not by successional stages. The successional stages affected the demographic dynamics with a mild impact on the genetic structure across age-classes of O. xalapensis. The scenic and recreational conservation strategies implemented in this forest have effectively allowed for population development of O. xalapensis and provide some explanation of genetic diversity at early-succession stage.

scholarly journals Successional stage effect on the availability of tree cavities for cavity-nesting birds in an Atlantic Forest park from the state of São Paulo, Brazil

2017 ◽  
Vol 17 (4) ◽  
Author(s):  
Michele Viana Katayama ◽  
Paulo Victor Queijo Zima ◽  
Daniel Fernandes Perrella ◽  
Mercival Roberto Francisco
Keyword(s):  
Atlantic Forest ◽  
Conservation Strategies ◽  
Southeastern Brazil ◽  
Human Disturbances ◽  
Successional Stage ◽  
Forest Park ◽  
Tree Cavities ◽  
Cavity Nesters ◽  
Cavity Nesting ◽  
Successional Stages

Abstract The availability of suitable cavities and substrate for hole construction can limit the populations of birds that rely on tree hollows to reproduce. Several studies have focused on the effects of types of habitats, and types of human disturbances on cavities abundance, but the effect of successional stages in the Atlantic Forest has been poorly addressed. In this study we aimed to compare the availability and biometric characteristics of tree cavities between primary and mid-successional stage sites in an Atlantic Forest area from southeastern Brazil. Based on nest characteristics described in the literature, we inferred if hollows present in secondary sites could harbor the large secondary-nester Atlantic Forest birds, with special attention to toucans and hawks. From September 2016 to April 2017, 96 cavities were sampled, 67 in the primary, and 29 in the secondary plots. Our data revealed that the communities of cavity-nester birds in mid-successional stage areas may be more affected by the reduced cavity availability than by cavities quality, as the number of cavities in these sites was less than half than that found in mature forests. We also provide evidences that the largest cavity nesters, such as the biggest hawks, might have limited nesting possibilities in mid-successional stage areas especially due to small cavity entrances, which may have important reflects in conservation strategies.

scholarly journals Effects of habitat fragmentation and human disturbance on the population dynamics of the Yunnan snub-nosed monkey from 1994 to 2016

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6633 ◽  
Author(s):  
Xumao Zhao ◽  
Baoping Ren ◽  
Dayong Li ◽  
Zuofu Xiang ◽  
Paul A. Garber ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Dynamics ◽  
Habitat Fragmentation ◽  
Population Size ◽  
Linear Models ◽  
Conservation Strategies ◽  
Source Population ◽  
Forest Patches ◽  
Current Conservation ◽  
Conservation Policies

In this study, we integrate data from field investigations, spatial analysis, genetic analysis, and Generalized Linear Models (GLMs) to evaluate the effects of habitat fragmentation on the population dynamics, genetic diversity, and range shifts in the endangered Yunnan snub-nosed monkey (Rhinopithecus bieti). The results indicate that from 1994 to 2016, R. bieti population size increased from less than 2,000 to approximately 3,000 individuals. A primary factor promoting population recovery was the establishment of protected nature reserves. We also found that subpopulation growth rates were uneven, with the groups in some areas, and the formation of new groups. Both the fragmentation index, defined as the ratio of the number of forest patches to the total area of forest patches (e.g., increased fragmentation), and increasing human population size had a negative effect on population growth in R. bieti. We recommend that government conservation plans prioritize the protection of particular R. bieti populations, such as the Baimei and Jisichang populations, which have uncommon haplotypes. In addition, effective conservation strategies need to include an expansion of migration corridors to enable individuals from larger populations such as Guyoulong (Guilong) to serve as a source population to increase the genetic diversity of smaller R. bieti subpopulations. We argue that policies designed to protect endangered primates should not focus solely on total population size but also need to determine the amount of genetic diversity present across different subpopulations and use this information as a measure of the effectiveness of current conservation policies and the basis for new conservation policies.

Monitoring forest plant biodiversity changes and developing conservation strategies: a study from Camili Biosphere Reserve Area in NE Turkey

Biologia ◽  
2010 ◽  
Vol 65 (5) ◽  
Author(s):  
Salih Terzioğlu ◽  
Emin Başkent ◽  
Fatih Sivrikaya ◽  
Günay Çakir ◽  
Ali Kadioğullari ◽  
...  
Keyword(s):  
Forest Succession ◽  
Secondary Forest ◽  
Biosphere Reserve ◽  
Structural Diversity ◽  
Conservation Strategies ◽  
Plant Biodiversity ◽  
Multiple Use ◽  
High Resolution Satellite Images ◽  
Successional Stages ◽  
Biodiversity Changes

AbstractThis study was carried out in forestland of Camili Biosphere Reserve (CBR) area in NE Turkey. It was designed to evaluate the consequences of disturbances on changes in secondary forest succession from 1985 to 2005 for monitoring forest plant biodiversity changes and developing conservation strategies. The successional stages were mapped using Geographic Information System (GIS), Global Positioning System (GPS), aerial photos and high resolution satellite images (IKONOS). The results showed that stable stage decreased about 77.96% over the last 20-year time period. Although 701.6 ha conifer forests existed in competition and reaction stages in 1985, none existed in 2005. In overall, about 33.23% of the area decreased, 42.36% did not change and 24.41% increased in different seral stages. Consequently, 8.83% of the area decreased as a whole to indicate that the forest has been developing from stable to nudation stage, that is to say, retrogressive succession is going on in the area. Forest structure and its relationship with plant biodiversity along with its changes over time were determined using FRAGSTATS. We also investigated spatio-temporal configuration of six secondary forest successional stages and generated structural diversity measures. These measures revealed that the landscape has been fragmented, posing a danger to lose the important components of plant biodiversity. Sustainable management of such degraded forests is of crucial importance for plant biodiversity conservation. In conclusion, the study contributes to the development of a framework for effective conservation of plant biodiversity through plant biodiversity integrated Multiple Use Forest Management (MUFM) plans by using the successional stages and plant biodiversity changes.

scholarly journals Population genetic structure of the Natterjack toad (Epidalea calamita) in Ireland: implications for conservation management

2021 ◽  
Author(s):  
Marina Reyne ◽  
Kara Dicks ◽  
Claire McFarlane ◽  
Aurélie Aubry ◽  
Mark Emmerson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Population Genetic ◽  
Species Conservation ◽  
Conservation Strategies ◽  
Population Declines ◽  
Effective Population ◽  
Genetic Structuring ◽  
Genetic Diversity And Structure ◽  
Epidalea Calamita

AbstractMolecular methods can play a crucial role in species management and conservation. Despite the usefulness of genetic approaches, they are often not explicitly included as part of species recovery plans and conservation practises. The Natterjack toad (Epidalea calamita) is regionally Red-Listed as Endangered in Ireland. The species is declining and is now present at just seven sites within a highly restricted range. This study used 13 highly polymorphic microsatellite markers to analyse the population genetic diversity and structure. Genetic diversity was high with expected heterozygosity between 0.55 and 0.61 and allelic richness between 4.77 and 5.92. Effective population sizes were small (Ne < 100 individuals), but not abnormal for pond breeding amphibians. However, there was no evidence of historical or contemporary genetic bottlenecks or high levels of inbreeding. We identified a positive relationship between Ne and breeding pond surface area, suggesting that environmental factors are a key determinant of population size. Significant genetic structuring was detected throughout the species’ range, and we identified four genetic entities that should be considered in the species’ conservation strategies. Management should focus on preventing further population declines and future loss of genetic diversity overall and within genetic entities while maintaining adequate local effective population size through site-specific protection, human-mediated translocations and head-start programs. The apparent high levels of genetic variation give hope for the conservation of Ireland’s rarest amphibian if appropriately protected and managed.

scholarly journals Genetic diversity and structure of Saussurea polylepis (Asteraceae) on continental islands of Korea: Implications for conservation strategies and management

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249752
Author(s):  
Seon A. Yun ◽  
Seung-Chul Kim
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Population Size ◽  
Anthropogenic Activities ◽  
Large Population ◽  
Conservation Strategies ◽  
Source Population ◽  
Genetic Diversity And Structure ◽  
Continental Islands

Saussurea polylepis Nakai is an herbaceous perennial endemic to Korea and is highly restricted to several continental islands in the southwestern part of the Korean Peninsula. Given its very narrow geographical distribution, it is more vulnerable to anthropogenic activities and global climate changes than more widely distributed species. Despite the need for comprehensive genetic information for conservation and management, no such population genetic studies of S. polylepis have been conducted. In this study, genetic diversity and population structure were evaluated for 97 individuals from 5 populations (Gwanmaedo, Gageodo, Hongdo, Heusando, and Uido) using 19 polymorphic microsatellites. The populations were separated by a distance of 20–90 km. We found moderate levels of genetic diversity in S. polylepis (Ho = 0.42, He = 0.43). This may be due to long lifespans, outcrossing, and gene flow, despite its narrow range. High levels of gene flow (Nm = 1.76, mean Fst = 0.09), especially from wind-dispersed seeds, would contribute to low levels of genetic differentiation among populations. However, the small population size and reduced number of individuals in the reproductive phase of S. polylepis can be a major threat leading to inbreeding depression and genetic diversity loss. Bayesian cluster analysis revealed three significant structures at K = 3, consistent with DAPC and UPGMA. It is thought that sea level rise after the last glacial maximum may have acted as a geographical barrier, limiting the gene flow that would lead to distinct population structures. We proposed the Heuksando population, which is the largest island inhabited by S. polylepis, as a source population because of its large population size and high genetic diversity. Four management units (Gwanmaedo, Gageodo, Hongdo-Heuksando, and Uido) were suggested for conservation considering population size, genetic diversity, population structure, unique alleles, and geographical location (e.g., proximity).

Habitat separation by sympatric forest grouse in Fennoscandia in relation to boreal forest succession

1993 ◽  
Vol 71 (7) ◽  
pp. 1303-1310 ◽  
Author(s):  
Jon E. Swenson ◽  
Per Angelstam
Keyword(s):  
Forest Succession ◽  
Deciduous Trees ◽  
Black Grouse ◽  
Forest Stands ◽  
Old Growth ◽  
Successional Stage ◽  
Hazel Grouse ◽  
Bonasa Bonasia ◽  
Successional Stages ◽  
Intensively Managed

Sympatric forest grouse in intensively managed conifer-dominated forests of the southern boreal zone in Sweden occupied different forest successional stages. Black grouse (Tetrao tetrix) selected forest stands 0 – 20 years old, hazel grouse (Bonasa bonasia) selected those 20 – 50 years old, and capercaillie (Tetrao urogallus) selected those ≥90 years old. Moreover, hazel grouse also selected stands with 1 – 10% deciduous trees, whereas capercaillie selected stands with no deciduous trees. The relative numbers of each grouse species were similar in two areas of intensively managed industrial forest, but differed in an area where forestry was less intensive and where forests had old-growth characteristics, i.e., they were old and multi-layered. Black grouse dominated in the intensively managed areas, whereas hazel grouse dominated in the less intensively managed area. We suggest that under natural conditions, black grouse inhabited the early-successional stages of forest following burns, hazel grouse inhabited the next, denser, successional stage and also old-growth spruce-dominated forests in fire refugia, and capercaillie inhabited stands of open, old, pine-dominated forest maintained by forest fire. The black grouse appears to be preadapted to the modern system of clearcut forest management. However, this system is clearly detrimental to the hazel grouse and capercaillie. To maintain all three species in a managed landscape, forest managers must strive to mimic more closely the natural variation in types and sizes of forest stands.

Evolutionary genetics of small populations

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Evolutionary Genetics ◽  
Small Population ◽  
Small Populations ◽  
Effective Population ◽  
Genetic Management ◽  
Evolutionary Genetic ◽  
Loss Of Genetic Diversity ◽  
Number Of Individuals

Genetic management of fragmented populations involves the application of evolutionary genetic theory and knowledge to alleviate problems due to inbreeding and loss of genetic diversity in small population fragments. Populations evolve through the effects of mutation, natural selection, chance (genetic drift) and gene flow (migration). Large outbreeding, sexually reproducing populations typically contain substantial genetic diversity, while small populations typically contain reduced levels. Genetic impacts of small population size on inbreeding, loss of genetic diversity and population differentiation are determined by the genetically effective population size, which is usually much smaller than the number of individuals.

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