scholarly journals Herbivore corridors sustain genetic footprint in plant populations: a case for Spanish drove roads

Author(s):  
Alfredo García-Fernández ◽  
Pablo Manzano ◽  
Javier Seoane ◽  
Francisco M Azcárate ◽  
José M Iriondo ◽  
...  

Habitat fragmentation is one of the greatest threats to biodiversity conservation and productivity, that are mediated by direct human impact. Its consequences include genetic depauperation, including phenomena such as inbreeding depression or reduction in genetic diversity. While the capacity of wild and domestic herbivores to sustain long-distance dispersal has been proven, the impact of herbivore corridors in plant population genetics remains to be observed. We conducted this study in the Conquense Drove Road in Spain, with a sustained use by livestock during centuries where transiting herds passed by twice a year en route to winter and summer pastures. We compared genetic descriptors of Plantago lagopus populations in the drove road with populations in the surrounding agricultural matrix, at varying distances from human settlements. We observed significant differences for coefficients of inbreeding between the drove road and the agricultural matrix, as well as significant trends for higher genetic diversity around human settlements. Trends for higher genetic diversity in drove roads may be present, although they were not significant with the available sample size. The resulting functional landscape has human settlements as dispersal hotspots, while the drove road act as a pollinator reservoir and possibly also as a linear structure facilitating long-distance dispersal in an agricultural matrix where local P. lagopus populations depend rather on short-distance dispersal. These results highlight the role of herbivore corridors for conserving the migration capacity of plants, and they contribute as well in understanding the role of human dispersal for the spread of invasive species.

2018 ◽  
Author(s):  
Alfredo García-Fernández ◽  
Pablo Manzano ◽  
Javier Seoane ◽  
Francisco M Azcárate ◽  
José M Iriondo ◽  
...  

Habitat fragmentation is one of the greatest threats to biodiversity conservation and productivity, that are mediated by direct human impact. Its consequences include genetic depauperation, including phenomena such as inbreeding depression or reduction in genetic diversity. While the capacity of wild and domestic herbivores to sustain long-distance dispersal has been proven, the impact of herbivore corridors in plant population genetics remains to be observed. We conducted this study in the Conquense Drove Road in Spain, with a sustained use by livestock during centuries where transiting herds passed by twice a year en route to winter and summer pastures. We compared genetic descriptors of Plantago lagopus populations in the drove road with populations in the surrounding agricultural matrix, at varying distances from human settlements. We observed significant differences for coefficients of inbreeding between the drove road and the agricultural matrix, as well as significant trends for higher genetic diversity around human settlements. Trends for higher genetic diversity in drove roads may be present, although they were not significant with the available sample size. The resulting functional landscape has human settlements as dispersal hotspots, while the drove road act as a pollinator reservoir and possibly also as a linear structure facilitating long-distance dispersal in an agricultural matrix where local P. lagopus populations depend rather on short-distance dispersal. These results highlight the role of herbivore corridors for conserving the migration capacity of plants, and they contribute as well in understanding the role of human dispersal for the spread of invasive species.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7311 ◽  
Author(s):  
Alfredo García-Fernández ◽  
Pablo Manzano ◽  
Javier Seoane ◽  
Francisco M. Azcárate ◽  
Jose M. Iriondo ◽  
...  

Habitat fragmentation is one of the greatest threats to biodiversity conservation and ecosystem productivity mediated by direct human impact. Its consequences include genetic depauperation, comprising phenomena such as inbreeding depression or reduction in genetic diversity. While the capacity of wild and domestic herbivores to sustain long-distance seed dispersal has been proven, the impact of herbivore corridors in plant population genetics remains to be observed. We conducted this study in the Conquense Drove Road in Spain, where sustained use by livestock over centuries has involved transhumant herds passing twice a year en route to winter and summer pastures. We compared genetic diversity and inbreeding coefficients of Plantago lagopus populations along the drove road with populations in the surrounding agricultural matrix, at varying distances from human settlements. We observed significant differences in coefficients of inbreeding between the drove road and the agricultural matrix, as well as significant trends indicative of higher genetic diversity and population nestedness around human settlements. Trends for higher genetic diversity along drove roads may be present, although they were only marginally significant due to the available sample size. Our results illustrate a functional landscape with human settlements as dispersal hotspots, while the findings along the drove road confirm its role as a pollinator reservoir observed in other studies. Drove roads may possibly also function as linear structures that facilitate long-distance dispersal across the agricultural matrix, while local P. lagopus populations depend rather on short-distance seed dispersal. These results highlight the role of herbivore corridors for conserving the migration capacity of plants, and contribute towards understanding the role of seed dispersal and the spread of invasive species related to human activities.


2015 ◽  
Vol 33 (4) ◽  
pp. 946-958 ◽  
Author(s):  
Isabel Alves ◽  
Miguel Arenas ◽  
Mathias Currat ◽  
Anna Sramkova Hanulova ◽  
Vitor C. Sousa ◽  
...  

2020 ◽  
Vol 108 (1) ◽  
Author(s):  
A. Kreitschitz ◽  
E. Haase ◽  
S. N. Gorb

AbstractMyxodiaspory (formation of mucilage envelope around seeds and fruits) is a common adaptation to dry habitats known in many families of Angiosperms. The mucilage envelope of some seeds seems to be also a unique morphological adaptation which protects myxospermatic diaspores while passing through the bird’s digestive system. To evaluate the protective potential of mucilage, we fed the diaspores of seven plant species (representing three different mucilage types and three species of non-mucilaginous plants) to pigeons, Columba livia domestica. Twenty-four hours later, we collected the droppings of pigeons and examined a total of 18,900 non-destroyed diaspores to check for mucilage presence and germination ability. Out of all the examined diaspores, 4.5% were mucilaginous seeds. Among them, the highest number (12.2–13.5%) of viable diaspores belonged to the hemicellulosic type of mucilage (from Plantago species). Only 3.7% of germinating diaspores with pectic mucilage (Linum usitatissimum) were collected, and no seeds representing cellulosic mucilage (e.g., Ocimum basilicum). For non-mucilaginous plants, we collected only a few individual seeds (0.1% out of 8100 seeds used). We noted that the mucilaginous seeds found in the droppings were able to germinate; however, the germination ability was generally smaller in comparison to the control (i.e., not digested) seeds. Our results revealed that the presence of mucilage envelope has an impact on diaspore dispersal and survivability. With our experiments, we demonstrated for the first time that the mucilage envelope, especially of the non-cellulosic type, supports endozoochory. We also showed that non-mucilaginous seeds can be occasionally dispersed via endozoochory and are able to germinate. The results of our studies can explain the ways of plants distribution at a small, local scale as well as in long-distance dispersal, e.g., between islands or even continents.


2011 ◽  
Vol 59 (3) ◽  
pp. 262 ◽  
Author(s):  
Gunnar Keppel ◽  
Peter Prentis ◽  
Ed Biffin ◽  
Paul Hodgskiss ◽  
Susana Tuisese ◽  
...  

We examined evolutionary relationships, hybridisation and genetic diversity in species of Dacrydium (Podocarpaceae) in Remote Oceania, where it is restricted to New Caledonia and Fiji. We used cpDNA sequence (trnL–trnF) data to construct a phylogeny and estimate taxon divergence by using a relaxed molecular clock approach. The phylogeny was verified using allozymes, which were also used to investigate genetic diversity of all species and the hybridisation dynamics of two endangered species, D. guillauminii and D. nidulum. Our results suggested that Dacrydium species in Remote Oceania form a monophyletic group that arose and diversified within the last 20 million years through long-distance dispersal and a range of speciation mechanisms. Whereas we detected no hybridisation between the Fijian species D. nausoriense and D. nidulum, we confirmed hybridisation between D. guillauminii and D. araucarioides in New Caledonia and determined introgression to be assymetric from the widespread D. araucarioides into the rare, restricted-range species D. guillauminii. In addition, D. guillauminii had lower genetic diversity than did the other species of Dacrydium studied, which had genetic diversity similar to that of other gymnosperms. Our results provided evidence for the recent and complex diversification of Dacrydium in Remote Oceania. In addition, low genetic diversity of and introgression from D. araucarioides, are of grave concern for the conservation of D. guillauminii.


2008 ◽  
Vol 65 (11) ◽  
pp. 2509-2523 ◽  
Author(s):  
Carey R. McGilliard ◽  
Ray Hilborn

We explored the effects of larval dispersal distance on the impact of no-take marine reserves (NTMRs) implemented in fisheries with catch regulations. NTMRs exist in many fisheries with harvest regulated by annual catch limits. In these fisheries, catch is taken from outside NTMRs, potentially resulting in reduced abundance outside NTMRs and an overall reduction in catch. We used a spatial model with two life stages (larvae and adults) to evaluate the effects of larval dispersal distance for fisheries managed by a total allowable catch (TAC) and an NTMR. We examined effects of the timing of density-dependent mortality in relation to larval movement. Abundance reached similar values for populations with long and short larval dispersal distances. Catch declined substantially for stocks with short larval dispersal distances. When larval dispersal distances were long, catch declined to values below maximum sustainable yield (MSY), but stabilized. Catch per unit effort (CPUE) declined to 9% of CPUE at MSY for stocks with short distance larval dispersal after the implementation of an NTMR; with long distance larval dispersal, CPUE declined to approximately 50% or less of the CPUE at MSY. The CPUE did not reflect trends in abundance after the implementation of an NTMR.


2004 ◽  
Vol 82 (6) ◽  
pp. 835-840 ◽  
Author(s):  
Jordi Figuerola ◽  
Andy J Green ◽  
Katrina Black ◽  
Beth Okamura

Waterbirds have been proposed as important vectors for the passive dispersal of those aquatic invertebrates and plants that lack a capacity for active dispersal between isolated water bodies. We analysed the frequency of internal transport of bryozoan propagules (statoblasts) by waterbirds in Doñana, Spain, by examining their presence in the intestines and ceca of dead birds and analysing the role of different aspects of gut characteristics in explaining variation in the presence/absence and abundance of statoblasts. Of the 228 samples examined, 7.9% presented intact statoblasts of Plumatella fungosa (Pallas, 1768), Plumatella emarginata Allman, 1844, and two unidentified Plumatella species. For a given bird species, individuals with heavier gizzards and shorter ceca had a lower incidence and abundance of statoblasts in the lower gut. Grit mass and intestine length were unrelated to the presence or abundance of statoblasts. Our results suggest that waterbirds frequently transport bryozoans on a local scale, with lighter gizzards and longer ceca favouring such transport. Lighter gizzards are likely to destroy fewer propagules before they reach the lower gut. Species and individuals with longer ceca are particularly good candidates for long-distance dispersal of bryozoans, given the longer passage time of propagules that enter the ceca.


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