Soil-litter ant (Hymenoptera: Formicidae) community response to reforested lands of Gishwati tropical montane forest, northern-western part of Rwanda

2021 ◽  
pp. 1-10
Author(s):  
Venuste Nsengimana ◽  
Wouter Dekoninck
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Native Species ◽  
Montane Forest ◽  
Tropical Montane Forest ◽  
Composition Analysis ◽  
Native Forest ◽  
Native Plant ◽  
Degraded Lands ◽  
Exotic Tree

Abstract Recently, human activities have impacted biodiversity-rich forest in western Rwanda, creating a need to enhance restoration activities of degraded lands in the region. To evaluate the effects of reforestation activities on the community composition of soil-litter ants, research was conducted in Gishwati tropical montane forest, located in northern-western part of Rwanda. The ant fauna was studied in reforested lands dominated by regenerated native species and exotic tree species. Further, a primary forest made of native trees served as a reference. In each forest type, nine sampling points were used to sample ants. Ant specimens were collected using pitfalls, hand sampling and Winkler extractor. They were identified to subfamilies, genus and species levels using dichotomous keys, and also statistically analysed for species richness, diversity, evenness and community composition. We collected a total of 2,481 individuals from 5 subfamilies, 18 genera and 35 species. Higher abundance, diversity and species richness were found in soil-litter under natural primary and secondary forests dominated by regenerated native plant species compared to exotic tree forest. The ant community composition analysis indicated higher similarities in ant species sampled under primary native forest and secondary forest dominated by regenerated native species. Reforestation by regenerating native species may be given priority in restoration of degraded lands due to their importance in species richness and species diversity.

scholarly journals Impacts of non-native Norway spruce plantation on abundance and species richness of ground beetles (Coleoptera: Carabidae)

Web Ecology ◽  
2001 ◽  
Vol 2 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Z. Elek ◽  
T. Magura ◽  
T. Tóthmérész
Keyword(s):  
Species Richness ◽  
Norway Spruce ◽  
Native Species ◽  
Detrimental Effect ◽  
Deciduous Forest ◽  
Management Practice ◽  
Beech Forest ◽  
Nature Management ◽  
Native Forest ◽  
Active Nature

Abstract. The impacts of non-native Norway spruce plantation on the abundance and species richness of carabids were studied in the Bükk National Park in Hungary, central Europe. Pitfall catches from recently established (5 yr old), young (15 yr after planting), middle-aged (30 yr after planting), old Norway spruce Picea abies plantation (50 yr after planting), and a native submontane beech forest (Fagetum sylvaticae) as a control stand were compared. Our results showed that deciduous forest species decreased significantly in abundance in the plantations, and appeared in high abundance only in the native beech forest. Furthermore, open habitat species increased remarkably in abundance in the recently established plantation. Carabids were significantly more abundant and species rich in the native forest than in the plantations, while differences were not significant among the plantations. Multiple regression between the abundance and species richness of carabids and twelve environmental measurements showed that pH of the soil, herb cover and density of the carabids’ prey had a significant effect in determining abundance and species richness. Our results showed that plantation of non-native Norway spruce species had a detrimental effect on the composition of carabid communities and no regeneration could be observed during the growth of plantations even 50 yr after the establishment. This emphasises the importance of an active nature management practice to facilitate the recolonization of the native species.

Impacts of erosion control treatments on native vegetation recovery after severe wildfire in the Eastern Cascades, USA

2010 ◽  
Vol 19 (4) ◽  
pp. 490 ◽  
Author(s):  
Erich K. Dodson ◽  
David W. Peterson ◽  
Richy J. Harrod
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Native Species ◽  
Plant Cover ◽  
Plant Species Richness ◽  
Tree Regeneration ◽  
Vegetation Recovery ◽  
Native Vegetation ◽  
Individual Plant ◽  
Native Plant

Slope stabilisation treatments like mulching and seeding are used to increase soil cover and reduce runoff and erosion following severe wildfires, but may also retard native vegetation recovery. We evaluated the effects of seeding and fertilisation on the cover and richness of native and exotic plants and on individual plant species following the 2004 Pot Peak wildfire in Washington State, USA. We applied four seeding and three fertilisation treatments to experimental plots at eight burned sites in spring 2005 and surveyed vegetation during the first two growing seasons after fire. Seeding significantly reduced native non-seeded species richness and cover by the second year. Fertilisation increased native plant cover in both years, but did not affect plant species richness. Seeding and fertilisation significantly increased exotic cover, especially when applied in combination. However, exotic cover and richness were low and treatment effects were greatest in the first year. Seeding suppressed several native plant species, especially disturbance-adapted forbs. Fertilisation, in contrast, favoured several native understorey plant species but reduced tree regeneration. Seeding, even with native species, appears to interfere with the natural recovery of native vegetation whereas fertilisation increases total plant cover, primarily by facilitating native vegetation recovery.

Conservation value of koa (Acacia koa) reforestation areas on Hawaii Island

2018 ◽  
Vol 24 (1) ◽  
pp. 35
Author(s):  
Laurie Strommer ◽  
Sheila Conant
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Native Species ◽  
Canopy Cover ◽  
Basal Area ◽  
Forest Tree ◽  
Native Forest ◽  
Acacia Koa ◽  
Total Species Richness ◽  
Hawaii Island

Efforts to restore forests for ecological and economic benefit in Hawaii are converging on koa (Acacia koa), an endemic dominant or codominant canopy tree common across broad elevation and moisture gradients. We quantified plant species composition and forest structure in koa reforestation areas (KRAs) and in nearby intact native forest on Hawaii Island. Total species richness and percentage native species richness were lower in the plantation forests than in the intact forests, although species richness in the KRAs at one site was not significantly different from that in intact forest. Tree, sapling, and seedling densities differed between KRAs and forest sites at one site. At another, the native forest and one KRA had similar tree and seedling densities and similar canopy height and percentage canopy cover. Total stand basal area was greatest in the intact forest at both sites, although the basal area for the KRAs at one site exceeded those for intact forest at the other. Koa plantings can be structurally similar to intact forests though species composition differs. Our results suggest that koa forestry can facilitate native understorey development in some cases.

Native plant species richness on Eastern Polynesia’s remote atolls

2015 ◽  
Vol 40 (1) ◽  
pp. 112-134 ◽  
Author(s):  
Sébastien Larrue ◽  
Jean-François Butaud ◽  
Pascal Dumas ◽  
Stéphane Ballet
Keyword(s):  
Species Richness ◽  
Sea Level ◽  
Plant Species ◽  
Native Species ◽  
Abiotic Factors ◽  
Plant Species Richness ◽  
Native Plant ◽  
Volcanic Island ◽  
Native Plant Species ◽  
Native Species Richness

Which abiotic factors influence the number of native plant species on remote atolls is an important question to understand better the spatial pattern of the species observed on these low and vulnerable coral islands. However, this issue is still very poorly documented, often due to human degradation, partial botanical surveys or the difficult geographic access of remote atolls for researchers. The remote atolls of Eastern Polynesia, which are among the most isolated in the world, are of great interest for studies of native species’ distribution due to their isolation, low human density and urbanisation. In this study, we selected 49 remote atolls of Eastern Polynesia with complete botanical surveys to test the relative influence of eight abiotic factors on native plant species richness (i.e. indigenous and endemic species). Abiotic factors used as potential predictors included atoll area (km2), shoreline length (km), atoll elevation (m) and index of isolation (UNEP), but also the coastal index of the atoll ( Ic), the distance to the nearest similar atoll (km), the distance to the nearest large volcanic island ≥ 1000 km2 (here, Tahiti as a potential stepping-stone island) and the distance to the nearest raised atoll ≥ 15 m a.s.l. (here, Makatea or Henderson as a potential refugium during sea-level highstands). Spearman’s rank correlation, linear regression analysis and frequency diagrams were used to assess the relative influence of these factors on native species richness. No relationship was found between the species richness and the index of isolation or the distance to the nearest similar atoll. Atoll area and distance to the nearest raised atoll of Makatea explained 47.1% and 40%, respectively, of the native species richness variation observed on the remote atolls. The distance to the volcanic island of Tahiti and the coastal index explained 36.9% and 27.3% of the variation, while elevation and shoreline length explained 23.3% and 18.4% of the variation, respectively. Native species richness on the atolls surveyed increased with the increasing atoll area, elevation and shoreline length, but decreased with the increasing distance to the nearest raised atoll of Makatea and the large volcanic island of Tahiti. This supports the view that the spatial pattern of native species richness observed on the remote atolls was strongly influenced by (i) atoll area but also by (ii) the distance to the raised atoll of Makatea, and (iii) the distance to the volcanic island of Tahiti. This finding suggests that the raised atoll may be viewed as a refugium during sea-level highstands while the large volcanic island played the role of stepping-stone island, both islands influencing the dispersal of native species on remote atolls and attenuating the isolation effect in the study area.

scholarly journals Cheatgrass invasion alters the abundance and composition of dark septate fungal communities in sagebrush steppe

Botany ◽  
2016 ◽  
Vol 94 (6) ◽  
pp. 481-491 ◽  
Author(s):  
Catherine A. Gehring ◽  
Michaela Hayer ◽  
Lluvia Flores-Rentería ◽  
Andrew F. Krohn ◽  
Egbert Schwartz ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Species ◽  
Mycorrhizal Fungi ◽  
Native Species ◽  
Invasive Plant ◽  
Soil Microbial Communities ◽  
Sagebrush Steppe ◽  
Native Plant ◽  
Native Plant Species ◽  
Dark Septate Fungi

Invasive, non-native plant species can alter soil microbial communities in ways that contribute to their persistence. While most studies emphasize mycorrhizal fungi, invasive plants also may influence communities of dark septate fungi (DSF), which are common root endophytes that can function like mycorrhizas. We tested the hypothesis that a widespread invasive plant in the western United States, cheatgrass (Bromus tectorum L.), influenced the abundance and community composition of DSF by examining the roots and rhizosphere soils of cheatgrass and two native plant species in cheatgrass-invaded and noninvaded areas of sagebrush steppe. We focused on cheatgrass because it is negatively affected by mycorrhizal fungi and colonized by DSF. We found that DSF root colonization and operational taxonomic unit (OTU) richness were significantly higher in sagebrush (Artemisia tridentata Nutt.) and rice grass (Achnatherum hymenoides (Roem. & Schult.) Barkworth) from invaded areas than noninvaded areas. Cheatgrass roots had similar levels of DSF colonization and OTU richness as native plants. The community composition of DSF varied with invasion in the roots and soils of native species and among the roots of the three plant species in the invaded areas. The substantial changes in DSF we observed following cheatgrass invasion argue for comparative studies of DSF function in native and non-native plant species.

scholarly journals Microclimate determines community composition but not richness of epiphytic understory bryophytes of rainforest and cacao agroforests in Indonesia

2009 ◽  
Vol 36 (2) ◽  
pp. 171 ◽  
Author(s):  
S. Goda Sporn ◽  
Merijn M. Bos ◽  
Monika Hoffstätter-Müncheberg ◽  
Michael Kessler ◽  
S. Robbert Gradstein
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Community Composition ◽  
Natural Forest ◽  
Native Forest ◽  
Shade Trees ◽  
Natural Forests ◽  
High Turnover ◽  
Forest Flora ◽  
Understory Trees

Management intensification in cultivated, tropical forests drives changes in the microclimate that can threaten native forest flora and fauna. In this study, we use epiphytic bryophytes, known to be sensitive to microclimatic changes due to their lack of a protective cuticle and the exposed habitat, to investigate the predictive power of microclimate for changes in species richness and composition. Bryophytes were sampled from understory trees in natural forest and cacao (Theobroma cacao L.) trees in two types of cacao agroforests (natural shade trees and planted shade trees) in Central Sulawesi, Indonesia. The microclimate in the agroforests was characterised by low air humidity and high air temperature during the afternoon. Bryophyte species richness did not differ between habitat types but species composition changed markedly from the natural forest to the cacao agroforests. Although no correlation between species richness and microclimate values could be found, a series of matrix-based analyses revealed a significantly positive relationship between similarities in species composition and in maximum values for temperature and minimum values for humidity, which suggests that microclimatic changes are a good predictor for high turnover of bryophyte community composition from natural forests to cacao agroforests.

Vegetation change in an urban grassy woodland 1974 - 2000

2004 ◽  
Vol 52 (5) ◽  
pp. 597 ◽  
Author(s):  
J. B. Kirkpatrick
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Exotic Species ◽  
Native Species ◽  
Vegetation Change ◽  
Structural Changes ◽  
Linear Models ◽  
Tree Cover ◽  
Native Plant ◽  
Native Species Richness

Few temporal studies document vegetation change in Australian temperate grassy woodlands. Floristic and structural data were collected from 68 randomly located sites in the Queens Domain, an urban grassy woodland remnant, in 1974, 1984, 1994 and 2000 and a search made for rare species. Species of conservation significance were concentrated at highly disturbed sites, whereas vegetation types of conservation significance decreased in area as a result of increases in the numbers of Allocasuarina verticillata, which caused a change in many unmown areas from Eucalyptus viminalis grassy woodland to E. viminalis–A. verticillata woodland/forest or A. verticillata open/closed forest. Structural changes were associated with changes in species composition and an increase in native-species richness. Increases in tree cover occurred where fires were most frequent, possibly as a result of the lack of mammalian herbivores. The frequencies of herbs and annual grasses were strongly affected by precipitation in the month of sampling. Half of the species that showed a consistent rise or fall through time were woody plants, approximately twice the number expected. In the dataset as a whole, species-richness variables were largely explained by varying combinations of variables related to moisture availability, altitude and the incidence of mowing. The strongest influences on species composition were the same, although slope and time since the last fire also contributed to multiple regression and generalised linear models. Compositional stability was positively related to native-species richness, whereas high levels of exotic-species richness occurred at both low and high levels of native-species richness. The maintenance of native-plant biodiversity on the Domain requires such counterintuitive measures as the maintenance of exotic trees and the control of native trees, demonstrating the contingencies of conservation management in fragmented vegetation that consists of a mixture of native and exotic species.

The impacts of invasive plant species on the biodiversity of Australian rangelands

2006 ◽  
Vol 28 (1) ◽  
pp. 27 ◽  
Author(s):  
A. C. Grice
Keyword(s):  
Invasive Species ◽  
Species Richness ◽  
Plant Species ◽  
Native Species ◽  
Invasive Plant ◽  
Plant Species Richness ◽  
Native Plant ◽  
Weed Species ◽  
Ecological Processes ◽  
Native Plant Species

Most parts of the Australian rangelands are at risk of invasion by one or more species of non-native plants. The severity of current problems varies greatly across the rangelands with more non-native plant species in more intensively settled regions, in climatic zones that have higher and more reliable rainfall, and in wetter and more fertile parts of rangeland landscapes. Although there is quantitative evidence of impacts on either particular taxonomic groups or specific ecological processes in Australian rangelands, a comprehensive picture of responses of rangeland ecosystems to plant invasions is not available. Research has been focused on invasive species that are perceived to have important effects. This is likely to down play the significance of species that have visually less dramatic influences and ignore the possibility that some species could invade and yet have negligible consequences. It is conceivable that most of the overall impact will come from a relatively small proportion of invasive species. Impacts have most commonly been assessed in terms of plant species richness or the abundance of certain groups of vertebrates to the almost complete exclusion of other faunal groups. All scientific studies of the impacts of invasive species in Australian rangelands have focused on the effects of individual invasive species although in many situations native communities are under threat from a complex of interacting weed species. Invasion by non-native species is generally associated with declines in native plant species richness, but faunal responses are more complex and individual invasions may be associated with increase, decrease and no-change scenarios for different faunal groups. Some invasive species may remain minor components of the vegetation that they invade while others completely dominate one stratum or the vegetation overall.

scholarly journals Species richness, phylogenetic diversity and phylogenetic structure patterns of exotic and native plants along an elevational gradient in the Himalaya

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Kumar Manish
Keyword(s):  
Species Richness ◽  
Exotic Species ◽  
Native Species ◽  
Phylogenetic Diversity ◽  
Elevational Gradient ◽  
Species Assemblages ◽  
Native Plant ◽  
Phylogenetic Structure ◽  
Phylogenetic Overdispersion ◽  
The Himalaya

Abstract Background So far, macroecological studies in the Himalaya have mostly concentrated on spatial variation of overall species richness along the elevational gradient. Very few studies have attempted to document the difference in elevational richness patterns of native and exotic species. In this study, this knowledge gap is addressed by integrating data on phylogeny and elevational distribution of species to identify the variation in species richness, phylogenetic diversity and phylogenetic structure of exotic and native plant species along an elevational gradient in the Himalaya. Results Species distribution patterns for exotic and native species differed; exotics tended to show maximum species richness at low elevations while natives tended to predominate at mid-elevations. Native species assemblages showed higher phylogenetic diversity than the exotic species assemblages over the entire elevational gradient in the Himalaya. In terms of phylogenetic structure, exotic species assemblages showed majorly phylogenetic clustering while native species assemblages were characterized by phylogenetic overdispersion over the entire gradient. Conclusions The findings of this study indicate that areas with high native species richness and phylogenetic diversity are less receptive to exotic species and vice versa in the Himalaya. Species assemblages with high native phylogenetic overdispersion are less receptive to exotic species than the phylogenetically clustered assemblages. Different ecological processes (ecological filtering in case of exotics and resource and niche competition in case of natives) may govern the distribution of exotic and native species along the elevational gradient in the Himalaya.

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