Short-term logging and burning impacts on species richness, abundance and community structure of birds in open eucalypt forest in Western Australia

2003 ◽  
Vol 30 (4) ◽  
pp. 321 ◽  
Author(s):  
Ian Abbott ◽  
Amanda Mellican ◽  
Michael D. Craig ◽  
Matthew Williams ◽  
Graeme Liddelow ◽  
...  

In 1985 new silvicultural prescriptions for managing jarrah (Eucalyptus marginata) forest in south-west Western Australia came into operation. The most extreme logging treatment (gap release) involved removal of most of the overstorey from patches no larger than 10 ha, followed by a regeneration fire. In the other logging treatment (shelterwood), less wood was removed from a larger area, also followed by a fire. This study examined the impact of these disturbances on the avifauna by monitoring species richness and abundance of birds one year before logging, one year before burning, and for five years after burning. Although 68 bird species were recorded during the seven years of the study, 29 of these were detected fewer than 15 times. Of the other 39 bird species recorded, only two (Gerygone fusca and Acanthiza apicalis) showed a statistically significant treatment effect over time on their abundance. The abundance of G. fusca initially declined in the disturbed treatments and by Year 7 of the study (5 years post-fire) in the gap-release treatment had not recovered its original abundance. A. apicalis increased its abundance in both shelterwood and gap-release treatments. By Year 7, both species in the logged treatments had abundances similar to those in the unlogged treatments. Total abundance of all species varied little across treatments. Species richness was highest by Year 7 in the shelterwood and lowest in the gap-release treatment. In some years community structure varied more at the external-reference sites (not recently logged or burnt) than at the gap-release sites. In particular, there was little overlap in community structure in the external-reference treatment between the first and final years, whereas the pre-logging and final year in the gap-release treatment showed a high degree of overlap. These differences are suggestive of overriding short-term annual variation in broad-scale factors rather than local factors. Yearly variation in rainfall and temperature was documented; during low rainfall periods, populations of foliage arthropods may have been reduced.

2014 ◽  
Vol 114 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Kathryn R. Napier ◽  
Suzanne H. Mather ◽  
Todd J. McWhorter ◽  
Patricia A. Fleming

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7501
Author(s):  
Guangyu Li ◽  
Walter Timo de Vries ◽  
Cifang Wu ◽  
Hongyu Zheng

Fallow management can improve the soil nutrients in the topsoil and upper subsoil. However, little is known about the effects of short-term (one year) fallowing with different treatments, such as vegetation and fertilization, on subsoil (20–40 cm) properties. We conducted field trials to explore the changes in subsoil properties in response to such treatments in the Yellow River Delta region in China. Different vegetation and fertilization treatments were applied, and we measured the carbon and nitrogen contents, microbial biomass and microbial community structure in the subsoil. Fallowing without manure resulted in the storage of more total nitrogen (16.38%) than fallowing with manure, and meadow vegetation improved the ammonium nitrogen content (45.71%) relative to spontaneous vegetation. Spontaneous vegetation with manure improved the microbial biomass nitrogen (P < 0.05). Although the impact of short-term fallowing on microbial community structure was low, an effect of management was observed for some genera. Blastopirellula, Lysobacter, and Acidobacteria Gp6 showed significant differences among fallow treatments by the end of the year (P < 0.05). Blastopirellula abundance was related to the microbial biomass nitrogen and nitrogen mineralization rate in the subsoil. Manure retained a high abundance of Lysobacter, which may strengthen soil-borne disease resistance. The response of Acidobacteria Gp6 showed that meadow vegetation without manure may not benefit future crops. Although the treatments did not significantly improve microbial community structure in the one-year period, annual fallowing improved certain subsoil properties and increased the number of functional genera, which may enhance crop productivity in the future.


1985 ◽  
Vol 12 (3) ◽  
pp. 461 ◽  
Author(s):  
I Abbott ◽  
PV Heurck

A study of foraging by 10 bird species suggests that selective logging of large Eucalyptus marginata will only have affected Melithreptus lunatus, but that proposed silvicultural treatments, including removal of Banksia grandis, may affect several other bird species.


Birds ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 329-337
Author(s):  
Alfonso Balmori

In recent decades, there has been a decline of the House Sparrow (Passer domesticus), mainly in European cities, and several hypotheses have been proposed that attempt to determine the causes of this rapid decline. Previous studies indicated that house sparrows were significantly negatively associated with increasing electromagnetic radiation and sparrows disappeared from areas most polluted. In addition, there are many studies on the impact of radiation on other bird and non-bird species, as well as numerous laboratory studies that demonstrated detrimental effects at electric field strength levels that can be found in cities today. Electromagnetic radiation is the most plausible factor for multiple reasons, including that this is the only one that affects the other hypotheses proposed so far. It is a type of pollution that affects productivity, fertility, decreases insects (chicken feed), causes loss of habitat, decreases immunity and can promote disease. Additionally, the recent sparrow decline matches the deployment of mobile telephony networks. Further, there are known mechanisms of action for non-thermal effects of electromagnetic radiation that may affect sparrows causing their decline. Thus, electromagnetic radiation must be seriously considered as a factor for house sparrows’ decline, probably in synergy with the other factors previously proposed.


2020 ◽  
Vol 9 (11) ◽  
pp. 3537
Author(s):  
Maria D. Alvarez-Bermudez ◽  
Flores Martin-Reyes ◽  
Luis Ocaña-Wilhelmi ◽  
Francisco J. Moreno-Ruiz ◽  
Juan Alcaide Torres ◽  
...  

Background The percentage of excess weight lost (%EWL) after bariatric surgery (BS) shows great discrepancies from one individual to another. Objective To evaluate the %EWL one year after BS and to determine the existence of baseline biomarkers associated with weight loss. Methods We studied 329 patients with morbid obesity undergoing three types of BS (biliopancreatic diversion (BPD), Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG)), depending on the %EWL one year after surgery: good responders (GR) (%EWL ≥ 50%) and non-responders (NR) (%EWL < 50%). Results The GR presented a higher percentage of change in anthropometric and biochemical variables compared to the NR group, even within each type of BS. There was a greater percentage of GR among those who underwent RYGB. The patients who underwent SG showed the lowest decrease in biochemical variables, both in GR and NR. Within the GR group, those with a lower age showed greater improvement compared to the other age groups. A %EWL ≥50% was negatively associated with the age and atherogenic index of plasma (AIP), and positively with the type of BS (RYGB). Conclusions The GR group was associated with lower age and AIP and undergoing RYGB. Additionally, those patients who underwent SG showed a lower metabolic improvement.


1984 ◽  
Vol 32 (4) ◽  
pp. 367 ◽  
Author(s):  
IJ Colquhoun ◽  
RW Ridge ◽  
DT Bell ◽  
WA Loneragan ◽  
J Kuo

Land use which reduces tree canopy density and the impact of Phytophthora cinnamomi are believed to be altering the hydrological balance of parts of the northern jarrah forest, Western Australia. In the drier eastern zones of the forest, replacement plant communities must maintain the soil-salt-water balance to prevent significant increases in salinization of streams in water supply catchments. Daily and seasonal patterns of the diffusive resistance of leaves and xylem pressure potential were determined for the major natural dominant of the region, Eucalyptus marginata, and five other species of Eucalyptus used in rehabilitation. Three types of daily and seasonal patterns were observed. E. marginata and E. calophylla exhibited little stomatal control of water loss, and leaf resistances remained low throughout the study period (type 1). E. maculata, E. resinifera and E. saligna exhibited marked stomatal regulation during summer days when xylem pressure potentials fell below -2.O MPa (type 2). E. wandoo (type 3) also controlled water loss but developed xylem pressure potentials far lower than all other species tested (<-3.0 MPa). Although none of the species tested replicated the summer stomatal resistance and xylem pressure potential patterns of E. marginata, it is suggested that total annual water use should be examined before selecting the most appropriate species to rehabilitate disturbed sites in the eastern zones of the northern jarrah forest region.


2019 ◽  
Vol 124 (3) ◽  
pp. 461-469 ◽  
Author(s):  
Xuejun Yang ◽  
Zhenying Huang ◽  
Ming Dong ◽  
Xuehua Ye ◽  
Guofang Liu ◽  
...  

Abstract Background and Aims Long-term studies to disentangle the multiple, simultaneous effects of global change on community dynamics are a high research priority to forecast future distribution of diversity. Seldom are such multiple effects of global change studied across different ecosystems. Methods Here we manipulated nitrogen deposition and rainfall at levels realistic for future environmental scenarios in three contrasting steppe types in Mongolia and followed community dynamics for 7 years. Key Results Redundancy analyses showed that community composition varied significantly among years. Rainfall and nitrogen manipulations did have some significant effects, but these effects were dependent on the type of response and varied between ecosystems. Community compositions of desert and meadow steppes, but not that of typical steppe, responded significantly to rainfall addition. Only community composition of meadow steppe responded significantly to nitrogen deposition. Species richness in desert steppe responded significantly to rainfall addition, but the other two steppes did not. Typical steppe showed significant negative response of species richness to nitrogen deposition, but the other two steppes did not. There were significant interactions between year and nitrogen deposition in desert steppe and between year and rainfall addition in typical steppe, suggesting that the effect of the treatments depends on the particular year considered. Conclusions Our multi-year experiment thus suggests that responses of community structure and diversity to global change drivers are ecosystem-dependent and that their responses to experimental treatments are dwarfed by the year-to-year community dynamics. Therefore, our results point to the importance of taking annual environmental variability into account for understanding and predicting the specific responses of different ecosystems to multiple global change drivers.


1998 ◽  
Vol 4 (1) ◽  
pp. 55 ◽  
Author(s):  
Merilyn J. Grey ◽  
Michael F. Clarke ◽  
Richard H. Loyn

The abundance of an aggressive Australian honeyeater, the Noisy Miner Manorina melanocephala, was reduced at four small (<8 ha) Grey Box Eucalyptus microcarpa woodland remnants by experimental removal. The diversity and abundance of small insectivorous and nectarivorous birds increased at three of the four sites (relative to matching control sites) over the twelve months following the removal of the Noisy Miners. The one exception occurred at a pair of sites where eucalypts began flowering at one site and finished at the other during the Noisy Miner removal period. These results, taken together with those from three earlier experiments where the abundance of Noisy Miners was reduced in Mugga Ironbark E. Sideroxylon woodland remnants, demonstrate that Noisy Miners affect avian diversity and abundance by aggressive exclusion of other species. In five out of seven experiments, Noisy Miners did not reinvade the small woodland remnants during the ensuing twelve months. When Noisy Miner abundance was reduced, increased populations of small insectivorous and nectarivorous birds used small degraded woodland remnants. Colonizing populations of small birds have the potential to reduce insect infestations and may assist in the recovery of dieback-affected woodland remnants. Research is continuing to test this hypothesis. Reducing the abundance of Noisy Miners in remnant eucalypt woodlands may also be a useful, short-term measure, which could assist in the recovery of threatened or endangered bird species.


1994 ◽  
Vol 45 (6) ◽  
pp. 963 ◽  
Author(s):  
IO Growns ◽  
JA Davis

The effects of forestry activities on macroinvertebrate community structure were examined in the headwaters of Carey Brook in the south-west of Australia. The fauna at four sites on an upland stream that ran through a logging coupe were compared, before and after clearfelling, with the fauna at four nearby undisturbed sites. Mean species richness and mean total abundance declined at the treatment sites relative to the control sites after the commencement of clearfelling activities. The composition of the macroinvertebrate fauna in the disturbed stream changed in comparison with that in the undisturbed sites after logging started but returned to the pre-logging composition after winter and spring rains had stopped. The observed changes in the macroinvertebrate fauna occurred during the periods of high loads of suspended inorganic solids at the treatment sites. The possible reasons for the observed results are discussed.


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