Response Of Flora Research Articles

Short-term soil fungal community dynamics following fire in mediterranean climate-type banksia woodlands

Fire is a dominant ecosystem process in many Mediterranean climate type ecosystems, and is predicted to increase in severity and frequency, shifting away from previous regimes in many regions. Responses of flora and fauna to fire are relatively well studied, but less is known about the responses of belowground microbiota. We quantified soil fungal dynamics over the first 12–15 months after fire, focusing on attributes of the fire regime (season, interval, severity). Soil samples were collected from three sites in a threatened woodland ecosystem in southwestern Australia, a Mediterranean-type climate region. Fungal taxa were identified via high throughput sequencing of the ITS subregion and taxonomy assigned using reference databases. Richness, diversity, abundance, community composition, and functional groups were quantified. Over the post-fire sampling period, richness and diversity declined and soil fungal community composition changed significantly throughout the sampling period, with family level taxa and functional groupings experiencing the most change. Through the sampling period, an increase in saprotrophic and endophytic fungi was observed, along with a decrease in all pathogenic fungi. We found that the post-fire fungal community is quite dynamic in the first 12–15 months after fire. We found little effect of fire interval or fire season, though our inference was limited. Our work contributes to putting belowground biota into the same conceptual frameworks as aboveground taxa and serves to inform fire managers in fire-prone Mediterranean climate type regions.

Responses of flora and fauna in wet eucalypt production forest to the intensity of disturbance in the surrounding landscape

Abstract In disturbance-dependent forest ecosystems, species associated with mature forest may maintain their ranges both by persisting in patches of mature forest and by recolonising patches regenerating after fire, harvesting or other disturbances. The null hypotheses are that these processes are both independent of the intensity of disturbance in the landscape surrounding those patches. These were tested in a 1120 km2 region of tall, wet eucalypt forest in southern Tasmania, which provides a landscape-scale gradient in disturbance intensity shaped by past wildfires and post-European land-use. For all 50 × 50 m cells in the region, a Landscape Disturbance Intensity (LDI) index was calculated based on the vegetation in the surrounding 0.5, 1.0 and 2.0 km-radius landscapes. The occurrence of species in three taxonomic groups – birds, vascular plants and flighted beetles – was then sampled in 28 plots (50 × 50 m) across the range of LDI in each of two forest age-classes – mature eucalypt forest (MAT) and 25–50 years-old silvicultural regeneration arising from clearfell harvesting (SILV). In both MAT and SILV plots, the occurrences of many common species showed significant relationships with LDI. Most (>80%) of those relationships reflected species that declined in occurrence with increasing LDI, i.e. were Landscape Disturbance-Sensitive (DSL). However, there were contrasting patterns between the forest age-classes as well as among the three taxonomic groups in the proportion of common species that were DSL. More plant and bird species were DSL in SILV plots (15/49 and 9/27, respectively) than in MAT plots (4/49 and 1/27, respectively). The dominant fractions of the DSL plant and bird species in SILV plots were classed as rainforest trees or shrubs in previous studies and birds that were associated with MAT plots rather than SILV plots in this study, i.e. species that were also sensitive to disturbance at the patch-scale. A similar number of the common beetle species were DSL in MAT plots (29/234) as in SILV plots (35/234). Beetle species that were Patch Disturbance-Sensitive (DSP) in this study were over-represented in the subset of DSL species in MAT plots (9/29), but not in SILV plots (5/35). We conclude that many DSP species inhabiting mature forest stands are resilient to disturbance in the surrounding landscape, but their ability to recolonise regenerating forest stands can be diminished by disturbance at the landscape-scale. This highlights the role of vegetation structure at both patch and landscape-scales in the long-term viability of mature-forest-dependent species in production-forest landscapes.

Where the wild things are: influence of radiation on the distribution of four mammalian species within the Chernobyl Exclusion Zone

Although nearly 30 years have passed since the Chernobyl Nuclear Power Plant accident near the town of Pripyat, Ukraine, the status and health of mammal populations within the Chernobyl Exclusion Zone (CEZ) remain largely unknown, and are of substantial scientific and public interest. Information regarding the response of flora and fauna to chronic radiation exposure is important in helping us understand the ecological consequences of past (eg Chernobyl and Fukushima) and potential future nuclear accidents. We present the results of the first remote‐camera scent‐station survey conducted within the CEZ. We observed individuals of 14 mammalian species in total; for those species with sufficiently robust visitation rates to allow occupancy to be modeled (gray wolf [Canis lupus], raccoon dog [Nyctereutes procyonoides], Eurasian boar [Sus scrofa], and red fox [Vulpes vulpes]), we found no evidence to suggest that their distributions were suppressed in highly contaminated areas within the CEZ. These data support the results of other recent studies, and contrast with research suggesting that wildlife populations are depleted within the CEZ.

Can retention forestry help conserve biodiversity? A meta-analysis.

Industrial forestry typically leads to a simplified forest structure and altered species composition. Retention of trees at harvest was introduced about 25 years ago to mitigate negative impacts on biodiversity, mainly from clearcutting, and is now widely practiced in boreal and temperate regions. Despite numerous studies on response of flora and fauna to retention, no comprehensive review has summarized its effects on biodiversity in comparison to clearcuts as well as un-harvested forests. Using a systematic review protocol, we completed a meta-analysis of 78 studies including 944 comparisons of biodiversity between retention cuts and either clearcuts or un-harvested forests, with the main objective of assessing whether retention forestry helps, at least in the short term, to moderate the negative effects of clearcutting on flora and fauna. Retention cuts supported higher richness and a greater abundance of forest species than clearcuts as well as higher richness and abundance of open-habitat species than un-harvested forests. For all species taken together (i.e. forest species, open-habitat species, generalist species and unclassified species), richness was higher in retention cuts than in clearcuts. Retention cuts had negative impacts on some species compared to un-harvested forest, indicating that certain forest-interior species may not survive in retention cuts. Similarly, retention cuts were less suitable for some open-habitat species compared with clearcuts. Positive effects of retention cuts on richness of forest species increased with proportion of retained trees and time since harvest, but there were not enough data to analyse possible threshold effects, that is, levels at which effects on biodiversity diminish. Spatial arrangement of the trees (aggregated vs. dispersed) had no effect on either forest species or open-habitat species, although limited data may have hindered our capacity to identify responses. Results for different comparisons were largely consistent among taxonomic groups for forest and open-habitat species, respectively. Synthesis and applications. Our meta-analysis provides support for wider use of retention forestry since it moderates negative harvesting impacts on biodiversity. Hence, it is a promising approach for integrating biodiversity conservation and production forestry, although identifying optimal solutions between these two goals may need further attention. Nevertheless, retention forestry will not substitute for conservation actions targeting certain highly specialized species associated with forest-interior or open-habitat conditions. Our meta-analysis provides support for wider use of retention forestry since it moderates negative harvesting impacts on biodiversity. Hence, it is a promising approach for integrating biodiversity conservation and production forestry, although identifying optimal solutions between these two goals may need further attention. Nevertheless, retention forestry will not substitute for conservation actions targeting certain highly specialized species associated with forest-interior or open-habitat conditions.

Ecosystem management based on large-scale disturbance pulses: A case study from sub-boreal forests of western Quebec (Canada)

The northern Témiscamingue region (western Québec) sustained regional-scale pulses of natural disturbances during the 1850–2000 period, such as severe fires during the 1908–1926 period, two severe spruce budworm outbreaks that occurred in 1909–1918 and 1974–1984, and two birch dieback episodes around 1940 and 1980. These disturbances produced synchronous fluctuations in forest characteristics over large spatial scales. In this paper, we review possible responses of flora and fauna to pulsed large-scale disturbance events and speculate on whether they should be emulated to reduce the impacts of forest management on non-timber resources. The importance of large-scale disturbance pulses for biodiversity and forest ecosystem integrity is potentially great, but this aspect has been poorly investigated by previous research, and thus there is little information available to guide forest management. Large-scale, synchronous disturbances could be emulated by clustering harvesting activities in time, for example by creating “harvest pulses” of 10–20 years, separated by periods of 50–100 years or so with low harvest rates. A potential disadvantage of this strategy is that when our capacity to predict future natural disturbances is low, there is a higher probability of accidentally taking the forest ecosystem outside of the range of natural variability compared with a status quo forest management scenario. From a socio-economic perspective, another potential disadvantage is in creating irregular wood flows to the forest transformation industry. Nonetheless, in a context where the forest has been over-disturbed in the recent past, a forest management strategy involving fluctuating harvest rates could provide the means for faster ecosystem recovery compared with a status quo strategy. We recommend that the potential importance of disturbance pulses for boreal and sub-boreal ecosystems be more thoroughly investigated by future research to inform management and conservation policies.

Ecological indicators applied to urban and suburban floras

Among the many approaches to ecological indicators, ecological indicators derived from the floristic composition of a site (i.e. Raunkiaer's forms spectrum or the percentage of different geographical distribution types-chorotypes) are well established in botanical and ecological literature. Nonetheless their relationship with other indicators, such as Ellenberg's ecological indicators, or the Grime model [Grime, J.P., 2002. Plant Strategies, Vegetation Processes and Ecosystem Properties. Wiley, Chichester] and the Hemeroby index [Kowarik, I., 1990. Some responses of flora and vegetation to urbanization in Central Europe. In: Sukopp, H., Hejny, S., Kowarik, I. (Eds.), Urban Ecology. Plants and plant communities in urban environments. SPB Academic Publishing, The Hague] is still poorly explored. We concentrated on an urban ecosystem because such areas, due to their high degree of artificialization, are particularly well suited for studying the interaction of anthropical disturbance with other processes of the ecosystems. This paper attempts to select a small indicator frameset of many already proposed indicators which best express the variability of the sites studied. A floristic-ecological investigation has been carried out in 10 urban sites, of which 6 were archeological, located in the centre of Rome and 4 suburban, semi-natural, in the NE of the town. Ecological indicators have been calculated on this data set. The Pearson correlation test was then applied to verify whether the indicators were independent, while stepwise regression analysis was done to evaluate the statistical weight of each ecoindicator. Disturbance and temperature are the main factors shaping the composition of the sites studied. They are largely interacting and are well expressed with the help of a small subset of the initial set of 19 indicators, namely, by indicators related to life forms and to the geographical distribution of species: Therophytes/Hemicryptophytes, Mediterranean/large distribution, Eurasiatic/large distribution, Mediterranean/Eurasiatic species. The information provided by Ellenberg's indicators values and Grime's life strategies are largely summarized by these chorological indicators.