scholarly journals A study of soil seed banks across one complete chronosequence of secondary succession in a karst landscape

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10226
Author(s):  
Xiaole He ◽  
Li Yuan ◽  
Zhen Hong Wang ◽  
Zizong Zhou ◽  
Li Wan
Keyword(s):  
Species Richness ◽  
Seed Germination ◽  
Secondary Succession ◽  
Life Forms ◽  
Seed Banks ◽  
Similar Species ◽  
Seed Density ◽  
Rocky Desertification ◽  
Karst Landscape ◽  
Before And After

Anthropogenic disturbance and distinctive geochemistry have resulted in rocky desertification in many karst regions of the world. Seed banks are crucial to vegetation regeneration in degraded karst ecosystems characterized by a discontinuous distribution of soil and seasonal drought stress. However, the dynamics of seed banks across one complete series of secondary succession and the underlying mechanisms remain unclear. We selected eight typical stages during secondary succession, conducted aboveground vegetation survey and collected 960 soil samples in the Guiyang karst landscape of China. Seed density, species richness and plant life forms in seed banks were determined via the germination method. The results indicated that the seed density in seed banks before and after field seed germination was significantly different among most succession stages. Community succession had impacts on the seed density of seed banks before and after field seed germination. Seed density ranged from 1,042 seedlings.m−2 in evergreen broadleaf forests to 3,755 seedlings.m−2 in the herb community, which was a relatively high density. The seed density and similar species composition between the seed banks and vegetation declined with succession from early to later stages. Species richness in seed banks was highest in middle succession stages and increased with increasing species richness of aboveground vegetation. The species richness of the five life forms in the seed banks showed different variations across these succession stages. The conservation of diverse aboveground vegetation can maintain the diversity of seed banks for restoration.

Seed-bank characteristics in mixed-mesophytic forest clearcuts and edges: Does "edge effect" extend to the seed bank?

2004 ◽  
Vol 82 (7) ◽  
pp. 992-1000 ◽  
Author(s):  
Rick E Landenberger ◽  
James B McGraw
Keyword(s):  
Species Richness ◽  
Edge Effect ◽  
Edge Effects ◽  
Seed Bank ◽  
Seed Banks ◽  
Seed Density ◽  
Forest Edges ◽  
Seed Shadow ◽  
Mesophytic Forest ◽  
Total Seed

Little is known about the seed banks of mixed-mesophytic forest clearcuts or their associated forest edges. Seed banks were described and compared to better understand how seed density, species richness, and composition change with increasing distance from clearcuts. Thirty-two taxa were found in the seed bank of clearcuts, and 44 were found in adjacent forest edges. Annuals represented 41% of seeds in clearcuts, but only 8% in edges, while trees and shrubs represented 3% in both areas. Seed-bank density and species richness varied significantly within and between clearcuts, but clearcuts were no different in seed-bank density and richness from interior forest seed banks. Seed-bank density declined significantly with distance from clearcuts on west-facing forest edges, but demonstrated no discernable spatial pattern on south-facing edges. Overall, edge effects from clearcutting on adjacent forest seed banks were demonstrated in total seed density and in several common wind-dispersed, early-successional herbaceous species, including Erechtites hieraciifolia (L.) Raf. and Lobelia inflata L., and Vitis, a common ingestion-dispersed species. The seed-shadow edge effect may influence both current and future community characteristics and population dynamics of vegetation in mixed-mesophytic forest edges adjacent to clearcuts.Key words: seed banks, clearcutting, edge effects, mixed-mesophytic forest, West Virginia.

scholarly journals Natural vegetation regeneration from soil seed banks in the cultivated edges of Sudd wetlands in Juba, Southern Sudan

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Josephine Esaete ◽  
Augustine Bongo ◽  
Thomas Lado ◽  
Tomor Bojoi ◽  
Henry Busulwa
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Seed Bank ◽  
Natural Regeneration ◽  
Soil Seed Bank ◽  
Seed Banks ◽  
Interquartile Range ◽  
Seed Density ◽  
Soil Seed Banks ◽  
Species Richness And Diversity

Soil seed banks are important for regeneration of degraded wetlands ecosystems. The Sudd wetlands of Juba city have long been encroached for crop cultivation. Seedling germination was monitored in a greenhouse to establish possible natural regeneration in Mindiari, Rejaf and Roton wetlands in the Sudd. Sixty-four species germinated from the soil seed bank of which 12.5% were dominated by Cyperus difformis and Typha capensis. The findings showed that median wetland species richness in Mindiari was 1.5 (interquartile range = 0.75?3.5), Rejaf 2.5 (interquartile range = 1.0 ? 4.0), Roton 3 (interquartile range = 1.0 ? 5.0) while median Shannon-Wiener diversity was 1.5 (1.14 ?1.73), 1.43 (1.01?1.66), 1.15 (0.98?1.67) for Mindiari, Rejaf and Roton respectively. Both the median seed species richness and diversity were not significantly different among the study wetlands. The median of seed density (56.1) was significantly higher in Roton than in Mindiari (36.7) and Rejaf (29.4) wetlands. The NMDS results showed that species composition of Mindiari and Rejaf was different from Roton. It is concluded that growing crops in wetlands did not influence species richness and diversity but it reduced seed density and altered species composition. Although wetland species were not significantly different in the three-wetland categories, dominance of canopy species belonging to Typhaceae and Cyperaceae indicates that these species are resilient to cultivation and could facilitate natural regeneration of cultivated wetlands edges of the Sudd region in Juba. Further research should examine effect of cultivation duration and flooding regimes on soil seed bank species richness, diversity, and density and composition.

Fire, Buried Germinable Seed Banks and Grass Species Establishment in an Urban Eucalypt Forest Reserve

1996 ◽  
Vol 44 (4) ◽  
pp. 413 ◽  
Author(s):  
BM Odgers
Keyword(s):  
Seed Banks ◽  
Grass Species ◽  
Similar Species ◽  
Forest Reserve ◽  
Eucalypt Forest ◽  
Open Forest ◽  
Forest Sites ◽  
Before And After ◽  
Species Establishment ◽  
Germinable Seed

The buried germinable seed banks of two natural contrasting savanna open-forest sites were investigated before and after a wildfire. It was found that while the number of buried germinable grass and sedge seeds remained the same, the number of buried germinable dicotyledon seeds in both sites increased after the fire. It was also found that there were similar species of grasses present in the buried germinable seed banks before and after the fire. When germinating grass seedlings in the burnt and unburnt sites were compared, similar species of grasses were found in the germinating seedlings at both sites; however, more grass seedlings germinated in the burnt site than in the unburnt site.

Effects of disturbance and altitude on soil seed banks of tropical montane forests

2013 ◽  
Vol 29 (6) ◽  
pp. 523-529 ◽  
Author(s):  
Denis Lippok ◽  
Florian Walter ◽  
Isabell Hensen ◽  
Stephan G. Beck ◽  
Matthias Schleuning
Keyword(s):  
Species Richness ◽  
Tropical Forests ◽  
Species Turnover ◽  
Habitat Type ◽  
Seed Banks ◽  
Seed Density ◽  
Forest Fragments ◽  
Forest Edges ◽  
Soil Seed Banks ◽  
Forest Remnants

Abstract:Vast areas of tropical forests have been deforested by human activities, resulting in landscapes comprising forest fragments in matrices of deforested habitats. Soil seed banks (SSB) are essential sources for the regeneration of tropical forests after disturbance. In a fragmented montane landscape in the Bolivian Andes, we investigated SSB in three different habitat types that were associated with different degrees of disturbance, i.e. in forest interior, at forest edges and in deforested habitats. Sampling of habitats was replicated at six sites ranging in altitude from 1950 to 2450 m asl. We extracted seeds from dried soil samples by sieving, classified seeds into morphospecies and size classes, and characterized SSB in terms of density, species richness and composition. We tested effects of disturbance (i.e. habitat type) and altitude on SSB characteristics. Overall, small seeds (<1 mm) dominated SSB (81% of sampled seeds). Seed density and species richness were lowest in deforested habitats, especially in large seeds and distant from adjacent forests (≥20 m), while small-seeded species were most numerous near forest margins. Species turnover between habitats was high. Altitude altered the composition of SSB, but had no effects on seed density and species richness. We conclude that the potential of SSB for natural regeneration of deforested habitats is low and decreases with increasing distance from forest remnants and that forest edges may be eventually invaded by small-seeded species from deforested habitats.

scholarly journals Getting the Most From Surveys: How Method Selection and Method Modification Impact Butterfly Survey Data

2021 ◽  
Author(s):  
Katherine C Kral-O’Brien ◽  
Adrienne K Antonsen ◽  
Torre J Hovick ◽  
Ryan F Limb ◽  
Jason P Harmon
Keyword(s):  
Species Richness ◽  
New Species ◽  
Count Data ◽  
Distance Sampling ◽  
Line Transect ◽  
Similar Species ◽  
Method Selection ◽  
M 10 ◽  
Sampling Procedures

Abstract Many methods are used to survey butterfly populations, with line transect and area surveys being prominent. Observers are typically limited to search within 5 or 10 m from the line, while observers are unrestricted in larger specified search regions in area surveys. Although methods differ slightly, the selection is often based on producing defendable data for conservation, maximizing data quality, and minimizing effort. To guide method selection, we compared butterfly surveys using 1) line versus area methods and 2) varying width transects (5 m, 10 m, or unrestricted) using count data from surveys in North Dakota from 2015 to 2018. Between line and area surveys, we detected more individuals with area surveys, even when accounting for effort. However, both methods accumulated new species at similar rates. When comparing transect methodology, we detected nearly 60% more individuals and nine more species when transect width increased from 5 m to unrestricted, despite similar effort across methodology. Overall, we found line surveys slightly less efficient at detecting individuals, but they collected similar species richness to area surveys when accounting for effort. Additionally, line surveys allow the use of unrestricted-width transects with distance sampling procedures, which were more effective at detecting species and individuals while providing a means to correct count data over the same transect length. Methods that reduce effort and accurately depict communities are especially important for conservation when long-term datasets are unavailable.

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