scholarly journals Forestry effects on a boreal ground beetle community in spring: Selective logging and clear-cutting compared

1997 ◽  
Vol 8 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Ola Atlegrim ◽  
Kjell Sjöberg ◽  
John Ball

To compare the effects of two tree harvesting methods (clear-cutting and single tree selection felling), spring-occurring ground beetles (Carabidae) were studied by pitfall trapping in northern Sweden. Species abundance, total abundance and Hill's diversity indices were used to compare the ground beetle community in clear-cuts to selectively-logged and to uncut control forests. In addition, to highlight the importance of site replication when evaluating a spatially-variable ecosystem like the boreal forest, we consider how our conclusions might have differed with and without site replication. Results from the two analyses differed considerably, highlighting the importance of site replication in studies offorestry effects in order to increase confidence in the conclusions. Overall, no significant harvest effects were found on the ground beetle community except for a significantly higher abundance of the open habitat species P. assimilis in clear-cuts than in uncut control forests. Our results thus do not support suggestions of an increase in diversity following clear-cutting, but are consistent with previous findings regarding increased abundances of open habitat species and no changes in abundance of forest generalists in clear-cuts. In general, the carabid community in the selection loggings resembled that in the uncut control forest, indicating a low effect of this harvesting method. Based on our analysis, we suggest that future studies of forestry impacts on invertebrates attempt to increase the number of sites evaluated rather than increase the number of samples from a given area.

2006 ◽  
Vol 17 (3) ◽  
Author(s):  
Lorna Cole ◽  
Meg Pollock ◽  
Duncan Robertson ◽  
John Holland ◽  
David McCracken

As a result of the European Community Common Agricultural Policy reform in 2005 it is predicted that livestock grazing in the Scottish uplands will become less intensive. At each of two upland research centres, two large (>40ha) plots were established to investigate the relationship between grazing intensity in the Scottish uplands and biodiversity. One plot was grazed intensively by sheep while the otherwas grazed extensively. Ground beetleswere sampled by pitfall trapping to determine the influence of grazing pressure on the ecologicalmake-up of ground beetle assemblages. Grazing intensity did not significantly influence carabid diversity. However, grazing intensity, altitude and moisture did influence the carabid ecological assemblage structure at both locations. Large flightless Carabus species were more abundant in extensively managed plots than intensively managed plots at both locations. It is likely that these long-living, relatively immobile beetles were favoured by the greater stability of the vegetation structure in the extensively grazed plots. Monitoring the ecological assemblage structure provides a more sensitive approach than diversity indices when comparing the impact of grazing and agricultural management but is also robust enough to allow direct comparisons between different geographical locations.


2021 ◽  
Vol 13 (10) ◽  
pp. 5747
Author(s):  
Dehuan Li ◽  
Wei Sun ◽  
Fan Xia ◽  
Yixuan Yang ◽  
Yujing Xie

Biodiversity maintenance is a crucial ecosystem service. Due to time limits and data availability, assessing biodiversity using indicators or models has become a hot topic in recent decades. However, whether some proposed indicators can explain biodiversity well at the local scale is still unclear. This study attempted to test whether the habitat quality index (HQI) as measured using the integrated valuation of ecosystem services and trade-offs (InVEST) model could explain variations in bird diversity in New Jiangwan Town, a rapidly urbanized region of Shanghai, China. The relationships from 2002 to 2013 among HQI and the two diversity indices, species richness and species abundance, were analyzed using Fisher’s exact test and gray correlation analysis. No significant association was found. Habitat connectivity was then integrated to develop a new combined indicator of habitat quality and connectivity index (HQCI). The associations between HQCI and the two diversity indices were improved significantly. The results indicated that connectivity may be an important factor explaining the diversity of certain species at a local scale. More empirical studies should be conducted to provide scientific evidence relating habitat quality to biodiversity.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Hellen K. Mandela ◽  
Mugatsia H. Tsingalia ◽  
Mary Gikungu ◽  
Wilbur M. Lwande

Pollination is an important ecosystem service in the maintenance of biodiversity and most importantly in food production. Pollination is on the decline due to habitat loss, exotic species invasions, pollution, overharvesting, and land use changes. This study analyzed the abundance and diversity of flower visitors’ of Ocimum kilimandscharicum in Kakamega forest with increasing distance from the forest edge. Data were collected through direct observation and sweep netting. Six study sites were identified along two transects each 2.5 km long and labeled A to F. Distance in metres from the forest edge to each site was A=221, B=72, C=83, D=198, E=113, and F=50. Sampling was done from 7:30 am to 4:00 pm, three days in a week for five months consecutively. Diversity indices of different flower visitors were calculated using the Shannon-Wiener diversity index. One-way analysis of variance was used to compare differences between sites and a two-sample t-test was used to identify mean significant differences in species diversity between the closest and the furthest sites. A total of 645 individuals belonging to 35 species were captured from 4 families. The highest diversity was at site F (H’= 2.38) which was closest to the forest edge and the lowest diversity was from site A (H’=1.44) which was furthest from the forest edge. Distance from the forest edge significantly influenced species diversity (F(3, 20)=14.67, p=0.024). Distance from the forest edge also significantly influenced species abundance between the furthest sites A, D, and E and the nearest sites F, B, and C to the forest edge (t=4.177; p=0.0312) and species richness (t=3.2893; p=0.0187). This study clearly demonstrates that Ocimum kilimandscharicum flower visitors play essential roles in pollination and their higher number of visits translates into higher numbers of seeds set. Many of these pollinators are associated with the forest and hence the need to conserve the Kakamega forest as a source pool for pollinators.


2019 ◽  
Vol 2 ◽  
Author(s):  
Matti Koivula

Many biological responses may develop over long periods of time, and annual community variation should therefore be controlled in ecological research. We sampled carabid beetles over ten years in Norway spruce dominated forests in Southern Finland, harvested using replicated logging treatments of different intensities. We collected carabids in 1995 (prior to logging) and during four post-harvest seasons, 1996-98 and in 2006. The treatments were clear-cutting (no retained trees), modified clear-cutting (retention of three groups of 20-30 trees within one-hectare core) and gap cutting (three 0.16-ha openings within a one-hectare core), and control (mature unharvested forest). Carabids showed remarkable annual and regional variation at assemblage, ecological-group and species levels, such that was independent of treatments. The total species richness, and that of open-habitat carabids, were higher in cleared sites of all treatments than in control stands in 1997-1998 but not in 2006, suggesting that the logging response was ephemeral by many species. The abundances of forest and generalist carabids were little affected by logging. Open-habitat carabids were more abundant in clear-cuts and modified clear-cuts than in gap cuts, which was still detectable in 2006, suggesting a long-term effect. Open-habitat carabids were less abundant in retention sites of modified clear-cuts and gap cuts than in cleared sites, suggesting that retention attenuates assemblage change. Carabid assemblages of logged stands did not differ from control stands in 1996 but they did in 1997-1998, suggesting a one-year delay in logging response. Carabids showed remarkable annual and regional variation at assemblage, ecological-group and species levels, such that was independent of treatments. The total species richness, and that of open-habitat carabids, were higher in cleared sites of all treatments than in control stands in 1997-1998 but not in 2006, suggesting that the logging response was ephemeral by many species. The abundances of forest and generalist carabids were little affected by logging. Open-habitat carabids were more abundant in clear-cuts and modified clear-cuts than in gap cuts, which was still detectable in 2006, suggesting a long-term effect. Open-habitat carabids were less abundant in retention sites of modified clear-cuts and gap cuts than in cleared sites, suggesting that retention attenuates assemblage change. Carabid assemblages of logged stands did not differ from control stands in 1996 but they did in 1997-1998, suggesting a one-year delay in logging response. In 2006, logged and control stands hosted relatively similar assemblages which, together with the above results, suggests a partial faunal recovery. We conclude that even modest retention provides long-term support for forest carabids, but also that their full assemblage recovery takes longer than 10 years.


2016 ◽  
Vol 64 (2) ◽  
pp. 875 ◽  
Author(s):  
Gonzalo D. Rubio

There is a clear connection between basic taxonomy and biodiversity issues. Faunistic studies with a taxonomically comprehensive inventory of species provide an important source of quantitative compiled information concerning several regions. This information can be used in diversity analysis and have great potential in setting conservation priorities. The salticid spider fauna of Misiones is relatively well known; here this knowledge is used to generate Clarke & Warwick taxonomic diversity indices. Different ecoregional diversities contributing to information about biodiversity levels of salticids in Misiones and providing reference data for future studies are analyzed. Differences between the three ecoregions of the province were found, mainly southern savannas regarding the forests of northern Misiones.


2020 ◽  
Vol 50 (7) ◽  
pp. 608-614
Author(s):  
Ronei Baldissera ◽  
Suiane Oliveira de Quadros ◽  
Gabriela Galeti ◽  
Everton Nei Lopes Rodrigues ◽  
Luan M.V. Lazzarotto ◽  
...  

Habitat loss is one of the main consequences of landscape transformation by humans. Monitoring biodiversity changes in areas under different management strategies is fundamental for species conservation. Our study is the first to assess the role of forest disturbance history on spider (Araneae) biodiversity in the westernmost portion of the Atlantic Forest. We analyzed taxonomic and functional aspects of spider assemblages in understories in a large forest fragment in southwestern Brazil. Spiders were sampled in five 30 m × 5 m plots over three seasons in three areas with different management histories: clear-cutting, selective logging, or native plots. We also characterized tree basal area, tree density, and canopy openness. The clear-cut plots showed more canopy openness and low habitat heterogeneity due to the high density of one pioneer native tree species. Forest structure in selective logging and native plots was similar. Spider richness, abundance, and functional richness were affected only by the season. Species composition also differed among the areas depending on the season. The abundance of web-building species was mainly associated with clear-cut areas in winter and spring. These results highlight the importance of natural regeneration in the Atlantic Forest after disturbance for the conservation of regional spider biodiversity.


2001 ◽  
Vol 17 (4) ◽  
pp. 549-561 ◽  
Author(s):  
WILFRIED PAARMANN ◽  
JOACHIM ADIS ◽  
NIGEL STORK ◽  
BURKHARD GUTZMANN ◽  
PHILIPP STUMPE ◽  
...  

The carabid beetle assemblage found feeding on fig fruit falls at night was studied in a terra firme rain forest near Manaus (Amazonia) from July 1991 to August 1996. A total of 8926 carabid beetles were collected on 64 fruit falls from 10 fig species. The most abundant genus was Notiobia with eight species, N. pseudolimbipennis being the most abundant. The Notiobia species comprised 92% of all specimens collected and all feed on small fig seeds. Their species abundance patterns varied considerably between individual fruit falls and during the course of a single fruit fall. However, the species abundance patterns for all Notiobia at all observed fruit falls for each of the two commonest fig species (Ficus subapiculata, F. guianensis), as well as for fruit falls of the remaining fig species, were very similar. Through feeding and breeding experiments and observations of reproductive success by dissection of females, only two of the eight Notiobia species were found to be specialized fig seed feeders, being able to reproduce only on fig fruit falls. The remaining six species of this genus use fig fruit falls as alternate hosts or ‘stepping stones’ between fruit falls of their host trees, which are widely separated both in time and space.


Oryx ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Ken Sugimura ◽  
Ken Ishida ◽  
Shintaro Abe ◽  
Yumiko Nagai ◽  
Yuya Watari ◽  
...  

AbstractWildlife populations on Amami Island, Japan, have been affected by forest clear-felling and the introduction of alien species, in particular the mongoose Herpestes auropunctatus. We used monitoring data collected over 24 years to track changes in the population sizes of five species of mammals and 20 species of birds. We assigned species to the following groups: indigenous, rare, insectivorous, negatively affected by forest clear-cutting, and negatively affected by mongoose invasion. We examined trends in each group at four time points between 1985 and 2010 using two methods: species abundance estimates and the Living Planet Index. We then assessed the usefulness of these methods as tools for conservation planning. Inspecting species individually we identified four main patterns of abundance change: (a) an increase from the first to the last census period, (b) an increase in all periods except 2009–2010, (c) a decrease from 1985–1986 to 2001–2002 but an increase in 2009–2010, and (d) a decrease in all census periods. We observed certain relationships between these patterns and the species groups assigned as above. According to the Living Planet Index the group negatively affected by forest clear-cutting did not show significant recovery and the groups of rare species and species negatively affected by mongoose recovered to c. 40% of the original level after a sharp decline during 1985–2002. The Living Planet Index is a more useful tool for assessing the urgency of particular conservation needs, although limited information on species abundance reduces its representativeness for some groups.


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