scholarly journals Rodent-mediated plant seed dispersal: what happens to the seeds after entering the gaps with different sizes?

Author(s):  
Fei Yu ◽  
Guangjie Li ◽  
Shanshan Wei ◽  
Xianfeng Yi ◽  
Jianmin Ma ◽  
...  

In general, it is accepted that gap formation significantly affects the placement of scatter-hoarded seeds by small rodents, but the effects of different forest gap sizes on the seed-eating and scatter-hoarding behaviors of small rodents remain unclear. Thus, we examined the effects of a closed canopy forest, forest edge, and gaps with different sizes on the spatial dispersal of Quercus variabilis acorns and cache placement by small rodents using coded plastic tags in the Taihang Mountains, China. The seeds were removed rapidly and there were significant differences in the seed-eating and caching strategies between the stand types. We found that Q. variabilis acorns were usually eaten after being removed from the closed canopy forest and forest edges. By contrast, the Q. variabilis acorns in the forest gap stands were more likely to be scatter hoarded. The dispersal distances of Q. variabilis acorns were significantly longer in the forest gap plots compared with the closed canopy and forest edge plots. However, the proportions of scatter-hoarded seeds did not increase significantly as the gap size increased. In small-scale oak reforestation projects or research, creating small gaps to promote rodent-mediated seed dispersal may effectively accelerate forest recovery and successional processes.

2018 ◽  
Author(s):  
A Dubuc ◽  
N. Waltham ◽  
R. Baker ◽  
C. Marchand ◽  
M. Sheaves

AbstractMangrove forests are important habitats for fish. However, their utilisation by fish, and the specific values they confer, are still not fully understood. This study describes how fish use mangrove forests in an Indo-Pacific mangrove-coral reef seascape. Sampling was conducted using underwater video cameras (UVCs) to describe spatial and temporal variations in fish assemblages across a small-scale (~ 2.5 km2) system, and over the tidal and lunar cycle. UVCs were deployed in the two main component habitats of mangrove forests: at the mangrove forest edge, and inside the forest (5 m from the forest edge), to establish patterns of utilisation of fish across the tidal and lunar cycle. Proximity to coral reefs had a strong influence on the mangrove fish community, as most fish recorded were reef-associated. Juveniles of 12 reef species were observed, including two species classified as vulnerable on the IUCN list, and one endemic species. Fish assemblages on the mangrove edge differed significantly from those inside the forest. Most fish utilised the forest edge, with few species making regular use of in-forest habitats, supporting the contention that most fish species remain on the edge and potentially retreat into the forest for opportunistic feeding, or when threatened by larger predators. Species-specific patterns of utilisation varied across the tidal and lunar cycle. Small differences in depth profiles and substrate across the small-scale system had a significant effect on fish assemblages, highlighting the importance of accounting for spatial heterogeneity in these factors. These data provide important information for managers to implement adequate conservation strategies that include broader interconnected habitat mosaics.


2013 ◽  
Author(s):  
Katharine L. Stuble ◽  
Courtney M. Patterson ◽  
Mariano A. Rodriguez-Cabal ◽  
Relena R. Ribbons ◽  
Robert R. Dunn ◽  
...  

Climate change affects communities both directly and indirectly via changes in interspecific interactions. One such interaction that may be altered under climate change is the ant-plant seed dispersal mutualism common in deciduous forests of the eastern US. As climatic warming alters the abundance and activity levels of ants, the potential exists for shifts in rates of ant-mediated seed removal. We used an experimental temperature manipulation at two sites in the eastern US (Harvard Forest in Massachusetts and Duke Forest in North Carolina) to examine the potential impacts of climatic warming on overall rates of seed dispersal (using Asarum canadense seeds) as well as species-specific rates of seed dispersal at the Duke Forest site. We also examined the relationship between ant critical thermal maxima (CTmax) and the mean seed removal temperature for each ant species. We found that seed removal rates did not change as a result of experimental warming at either study site, nor were there any changes in species-specific rates of seed dispersal. There was, however, a positive relationship between CTmax and mean seed removal temperature, whereby species with higher CTmax removed more seeds at hotter temperatures. The temperature at which seeds were removed was influenced by experimental warming as well as diurnal and day-to-day fluctuations in temperature. Taken together, our results suggest that while temperature may play a role in regulating seed removal by ants, ant plant seed-dispersal mutualisms may be more robust to climate change than currently assumed.


2009 ◽  
Vol 28 (2) ◽  
pp. 191-205 ◽  
Author(s):  
S. Steyaert ◽  
J. Bokdam ◽  
W. Braakhekke ◽  
S. Findo

2019 ◽  
Vol 32 (3) ◽  
pp. 243-251 ◽  
Author(s):  
Jeffrey A. Harvey ◽  
Lucas de Haan ◽  
Oriol Verdeny-Vilalta ◽  
Bertanne Visser ◽  
Rieta Gols

Abstract Closely related species in nature usually exhibit very similar phylogenetically conserved traits, such as reproduction, behavior and development. Here, we compared fecundity schedules, lifetime reproductive success and offspring sex ratios in three congeneric facultative hyperparasitoid wasps that exhibit several overlapping traits and which co-occur in the same small-scale habitats. Gelis agilis, G. proximus and G. hortensis are abundant in meadows and forest edge habitats in the Netherlands. Gelis agilis is asexual (all female), whereas the other two species reproduce sexually. Here they developed on cocoons of the primary parasitoid Cotesia glomerata. When provided with unlimited hosts, lifetime reproductive success was three times higher in G. proximus than in G. agilis with G. hortensis producing intermediate numbers of offspring. All three species depleted their teneral reserves during their lives. Females of G. proximus and G. hortensis lived significantly longer than females of G. agilis. Offspring sex ratios in young G. proximus mothers were female-biased and marginally male-biased in G. hortensis. As mothers aged, however, the ratio of male:female progeny produced rapidly increased until no daughters emerged later in life. Our results reveal significant differences in reproductive traits among the three species despite them co-occurring in the same microhabitats, being very closely related and morphologically similar. The increase in the production of male progeny by Gelis mothers over time suggests a depletion in sperm number or viability with age. This is especially interesting, given that Gelis species are among the least fecund parasitoids thus far studied. It is likely that in the field most Gelis mothers are probably only able to parasitize a few hosts and to maintain the production of female offspring.


Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 806
Author(s):  
Shen ◽  
Yang ◽  
Zhang ◽  
Xu ◽  
Zhang ◽  
...  

Changes in the microenvironment driven by forest gaps have profound effects on soil nutrient cycling and litter decomposition processes in alpine forest ecosystems. However, it is unclear whether a similar forest gap effect occurs in the soil decomposer community. A field experiment was conducted in an alpine forest to investigate the composition and structure of the soil nematode community among four treatments, including under a closed canopy and in small (<10 m in diameter), medium (10‒15 m in diameter), and large (15‒20 m in diameter) gaps. A total of 92,787 individuals and 27 species (genera level) of soil nematode were extracted by elutriation and sugar centrifugation, respectively. Filenchus was the most abundant dominant taxa and represented 24.27%‒37.51% of the soil nematodes in the four treatments. Compared to the closed canopy, the forest gaps did not affect the composition, abundance, or species diversity of the soil nematode community but significantly affected the functional diversity of the soil nematode community. The maturity indices (MI, ∑MI, and MI2‒5) of the soil nematode community in the closed canopy were significantly lower than those in the forest gaps. Moreover, the proportion of plant parasitic index and maturity index (PPI/MI) values of the closed canopy and small gaps were significantly higher than those of the medium and large gaps. Our results suggest that the forest gap size substantially alters the functional diversity of soil nematodes in the debris food web, and changes in soil nematode community structure due to gap formation may have profound effects on soil biogeochemical processes in alpine forests.


1991 ◽  
Vol 2 (2) ◽  
pp. 165-172 ◽  
Author(s):  
J. Ogden ◽  
R. A. Fordham ◽  
S. Pilkington ◽  
R. G. Serra

Plant Science ◽  
2014 ◽  
Vol 223 ◽  
pp. 124-133 ◽  
Author(s):  
Rivka Elbaum ◽  
Yael Abraham
Keyword(s):  

1996 ◽  
Vol 20 (3) ◽  
pp. 292-310 ◽  
Author(s):  
Arthur W. L. Veen ◽  
Wim Klaassen ◽  
Bart Kruijt ◽  
Ronald W.A. Hutjes

Although the soil-vegetation-atmosphere exchange of momentum and heat is fairly well understood for many types of homogeneous surfaces, the disturbances created by tran sitions of one surface type to another remain to be analysed more fully. This is especially true for the impact which a large transition such as the forest edge has on the average fluxes in a small-scale heterogeneous landscape with forest. Recently acquired experimental evidence appears to some extent contradictory and at variance with conventional concepts.


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