scholarly journals The effects of forest edge and nest height on nest predation in a U.K. deciduous forest fragment

Author(s):  
Noah Atkin ◽  
Cris Banks-Leite

It has been previously hypothesised that nest predation is higher at forest edges. This has important conservation implications for the increasingly fragmented U.K. climax community. I aimed to test the generality of this edge effect in a mixed deciduous forest fragment which borders open grassland. Artificial nests containing a combination of quail and plasticine eggs were used, at ground and arboreal levels. I found an overall edge effect on nest predation rates, however this effect was not specifically seen in ground nests. Ground nests experienced significantly higher levels of predation than arboreal nests. I suggest this edge effect is due in part to the steep productivity gradient over the ecotone.

2002 ◽  
Vol 29 (4) ◽  
pp. 341 ◽  
Author(s):  
Lainie Berry

Predation rates of nests at human-induced habitat edges may be greater than in forest interior due to differences in predator assemblages and predator activity. I compared the predation rates on 192 artificial nests containing plasticine eggs placed in forest edge and interior sites at Bunyip State Park, Victoria. The nest-predation rates at the forest edge sites were significantly greater (mean = 52–58%) than that at the forest interior sites (mean = 30–39%). The relative rates of predation by birds compared with mammals were significantly greater at forest edge sites (mean = 78–94%) than at forest interior sites (mean = 36–67%). Higher rates of nest predation at forest edges appeared to be due to greater densities of avian predators such as the grey shrike-thrush (Colluricincla harmonica), and/or lower abundances of small mammals. However, biases towards certain predator types may mask real, or create false, patterns in predation rates of artificial nests. A better understanding of how predators respond to artificial nests compared with natural nests is required. Until then, results of predation studies that use artificial nests should be interpreted with caution.


2016 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Poliana Gabriella Araújo Mendes ◽  
Maria Amanda Menezes Silva ◽  
Tassiane Novacosque Feitosa Guerra ◽  
Ana Carolina Borges Lins-e-Silva ◽  
Airton de Deus Cysneiros Cavalcanti ◽  
...  

ABSTRACT The woody plants in an edge area formed approximately 35 years ago in an Atlantic Forest fragment in northeastern Brazil were examined, and three environments defined: edge, intermediate, and interior. Canopy tree densities and basal areas were found to be similar in all three environments, and also similar to previous published studies in the same region; species richness was greatest at the forest edge. The understory showed greater species richness in the forest interior, but greater diversity and equitability in the intermediate environment. Understory environments close to the forest edge demonstrated larger stem diameters than in the forest interior, although at lesser densities and with smaller total basal areas. Our results indicated the existence of distinct patterns in canopy and understory that most likely reflect differences in the response times of these two vegetation layers, with the understory being more sensitive to alterations in environmental structure.


2002 ◽  
Vol 29 (2) ◽  
pp. 127 ◽  
Author(s):  
S. Piper ◽  
C. P. Catterall ◽  
M. F. Olsen

Edge-related increases in nest-predation levels were tested using artificial nests placed within eucalypt forest remnants at distances of 0, 60, and 235 m from edges adjacent to areas of urban, pasture, and Pinus plantation. There were eight replicate sites of each edge type, scattered widely across a 30 000-km2 study region. Open-cup nests containing one quail egg and two plasticine eggs were placed in shrubs and exposed for 6 days. When predation of the quail egg was used to calculate predation levels, predation varied significantly with edge type but not distance to the edge, due to relatively low levels within sites bordering Pinus plantations. When predation of any egg was used to calculate predation levels, predation was not significantly affected by edge type or distance to the edge. Predation levels within eight independent forest interior transects distributed across the study region, and located 500-800 m from the nearest edge, were similar to those within transects 0 m from edges. Birds were the most important class of predator within all combinations of site type and distance to edge, and accounted for 92% of identified predation overall. These results do not support the existence of edge-related increases in predation of shrub nests within subtropical eucalypt forests.


The Auk ◽  
2004 ◽  
Vol 121 (1) ◽  
pp. 162-169 ◽  
Author(s):  
Jacques Ibarzabal ◽  
André Desrochers

Abstract High nest-predation risk is often associated with forest edges. Most nest predators in boreal coniferous forests of North America are forest specialists living in mature stands. Nest predators have been studied mainly through use of artificial nests; knowledge of their behavior remains limited. We used radiotelemetry to examine movement patterns, relative to forest edge, of a forest nest predator, the Gray Jay (Perisoreus canadensis), in boreal coniferous forest. Each of 11 family groups of Gray Jays monitored in early summer exhibited a marked association with forest edges. Jays were found within 30 m of the forest edges more often than expected from random use of mature forest. Furthermore, jays traveled more slowly near forest edges than in the forest interior. Because forest edges apparently represent prime foraging habitat for Gray Jays, narrow forest strips left by logging could act as ecological traps for mature-stand songbirds before stands regenerate in adjacent clearcuts.


1993 ◽  
Vol 20 (6) ◽  
pp. 711 ◽  
Author(s):  
WF Laurance ◽  
J Garesche ◽  
CW Payne

Predation on artificial avian ground-nests was assessed from March to December 1991 in rainforest and nearby modified habitats in tropical Queensland. Data from 610 experimental nests were used to determine relative predation intensity in five types of habitat or microhabitat. Nest predators were identified with live-traps, with baited grease-plates and by regular observations of 380 additional nests. Predation intensity was patchy but often heavy in forested habitats (rainforest interiors, secondary forest, rainforest-pasture edges, and a rainforest-secondary forest edge) and negligible in adjoining cattle pastures. Forest edges exhibited no obvious edge-interior gradients in predation intensity. Most predation occurred at night in rainforest (88%) and secondary forest (61%), and patterns of egg damage suggested that mammals were responsible for most (>71%) nest predation. A combined nest-predation and live-trapping experiment on six study plots revealed that the abundance of white-tailed rats (Uromys caudimaculatus) was a highly effective predictor of local predation intensity (F=30.15, r*2=0.85, P=0.004). One of Australia's largest rodents, the white-tailed rat may be a key opportunistic predator of some bird nests in north Queensland rainforest.


The Condor ◽  
2000 ◽  
Vol 102 (2) ◽  
pp. 256-266 ◽  
Author(s):  
Maiken Winter ◽  
Douglas H. Johnson ◽  
John Faaborg

Abstract We tested how edges affect nest survival and predator distribution in a native tallgrass prairie system in southwestern Missouri using artificial nests, natural nests of Dickcissels (Spiza americana) and Henslow's Sparrows (Ammodramus henslowii), and mammal track stations. Survival of artificial nests was lower within 30 m of forest edge. Nesting success of Dickcissels and Henslow's Sparrows was lower within 50 m to a shrubby edge than at greater distances, whereas fates of nests were not related to distances to roads, agricultural fields, or forests. Evidence from clay eggs placed in artificial nests indicated that mid-sized carnivores were the major predators within 30 m of forest edges. Furthermore, mid-sized carnivores visited track stations most frequently within 50 m of forest edges. Because proximity of woody habitat explained more variation in nest survival and mammal activity than did fragment size, it appears that edge effects were more pronounced than area effects. Edge effects appeared to be caused mainly by greater exposure of nests to mid-sized carnivores. We argue that, based on edge avoidance behavior, “grassland-interior” species such as the Henslow's Sparrow respond to edge effects mainly by a decrease in density, whereas habitat generalists such as the Dickcissel are affected mainly by a decrease in nesting success.


Author(s):  
László Erdős ◽  
Katalin Szitár ◽  
Kinga Öllerer ◽  
Gábor Ónodi ◽  
Miklós Kertész ◽  
...  

AbstractPrevious studies found that pedunculate oak, one of the most widespread and abundant species in European deciduous forests, regenerates in open habitats and forest edges, but not in closed forest interiors. However, these observations usually come from the core areas of the biome, and much less is known about such processes at its arid boundary, where limiting factors may be different. In a full factorial field experiment, we tested the effects of different habitats (grassland, forest edge, forest interior) and increased growing season precipitation on the early regeneration of pedunculate oak in a forest-steppe ecosystem in Central Hungary, at the arid boundary of temperate deciduous forests. In the grassland habitat, seedling emergence was very low, and no seedlings survived by the fourth year. In contrast, seedling emergence was high and similar at forest edges and forest interiors, and was not affected by water addition. Most seedlings survived until the fourth year, with no difference between forest edge and forest interior habitats in numbers, and only minor or transient differences in size. The lack of oak regeneration in the grassland differs from previous reports on successful oak regeneration in open habitats, and may be related to a shift from light limitation to other limiting factors, such as moisture or microclimatic extremes, when moving away from the core of the deciduous forest biome towards its arid boundary. The similar number and performance of seedlings in forest edges and forest interiors may also be related to the decreasing importance of light limitation.


2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Patrícia Anjos Bittencourt Barreto-Garcia ◽  
Rafael Nogueira Scoriza ◽  
Alessandro de Paula

ABSTRACT The magnitude of changes in soil attributes can be used to identify the effects of natural or anthropogenic interference on forest fragments. The objective of this work was to evaluate the chemical attributes of the soil as indicators of the edge effect at a Seasonal Semi-deciduous Forest fragment in the Southwest of Bahia, Brazil. Four sampling ranges were defined in the forest fragment (Range 1: 0-10m; Range 2: 40-50 m; Range 3: 80-90 m; and Range 4: 400-410 m from the edge). A degraded native pasture area was used as the reference. Soil samples were collected at depths of 0-5, 5-10 and 10-20 cm. The samples were analyzed for pH and organic matter, P, K, Ca, Mg and Al. The superficial layer of the soil was sensitive to the changes imposed by the fragmentation, reflecting modifications in some of its chemical attributes up to a distance of 90 m from the edge towards the interior of the fragment, with more severe effects in the first 10 meters. Soil organic matter, potential acidity, CEC and pH were the most affected attributes, evidencing a gradient of variation in the edge-interior direction.


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