The effects of experimental patch burning and rainfall on small mammals in the Simpson Desert, Queensland

2003 ◽  
Vol 30 (6) ◽  
pp. 547 ◽  
Author(s):  
Mike Letnic

Patch-burning is frequently advocated as a management tool to enhance the biodiversity and pasture values of spinifex (Triodia) grasslands. In the northern Simpson Desert, Queensland, pastoralists use fire to reduce the likelihood of broad-scale wildfires and improve pastures for cattle. I conducted a before–after–control–impact experiment to investigate the response of small mammals to the short-term (<1 year) effects of patch-burning between August 1999 and June 2001. The experiment was replicated at three locations subject to differing rainfalls, with two 1-ha study grids remaining unburnt as controls, and two being burnt at each location. The areas burnt ranged from 1 to 3 ha. Dasycercus cristicauda and Pseudomys desertor responded negatively to the fire treatment. Notomys alexis responded positively to the fire treatment in the final trapping session but only at one location. Factors indicative of temporal and spatial variation in rainfall, time and site had a greater effect on the abundance of small mammals than the fire treatment. Heavy rainfalls in 2000 increased seed production and prompted increases in the populations of rodent species and Dasycercus cristicauda. The greatest numbers of captures were made at the sites that received the highest rainfalls. Patch-burning regimes are likely to increase the resilience of 'fire-sensitive' species dependent on dense spinifex by reducing the extent of wildfires.

1993 ◽  
Vol 20 (6) ◽  
pp. 803 ◽  
Author(s):  
P Masters

Fire-driven succession and a period of high rainfall had a pronounced effect on the distribution and abundance of small mammals inhabiting spinifex grassland in Uluzu National Park from 1987 to 1990. Species richness and abundance were generally higher on sites burnt in 1976, where six species (Pseudomys hermannsburgensis, Pseudomys desertor, Mus domesticus, Dasycercus cristicauda, Ningaui ridei and Sminthopsis youngsoni) were caught more frequently. Two species (Notomys alexis and Sminthopsis hirtipes) were more abundant on sites burnt in 1986. Murid rodent numbers fluctuated substantially following high rainfall. The number of individuals increased 100-fold, and species richness increased from two to four when P. desertor and M. domesticus appeared in the second year of the study. In contrast, captures of dasyurid marsupials increased only slightly over the three years, with the most dramatic increase occurring for D. cristicauda. This study highlights the importance of fire as a management tool. Patch burning within spinifex grasslands maximises species diversity of small mammals by ensuring that suitable successional states are present at all times. This is particularly important for species that are restricted in their distribution, such as D. cristicauda


Paleobiology ◽  
2021 ◽  
Vol 47 (2) ◽  
pp. 171-177
Author(s):  
James C. Lamsdell ◽  
Curtis R. Congreve

The burgeoning field of phylogenetic paleoecology (Lamsdell et al. 2017) represents a synthesis of the related but differently focused fields of macroecology (Brown 1995) and macroevolution (Stanley 1975). Through a combination of the data and methods of both disciplines, phylogenetic paleoecology leverages phylogenetic theory and quantitative paleoecology to explain the temporal and spatial variation in species diversity, distribution, and disparity. Phylogenetic paleoecology is ideally situated to elucidate many fundamental issues in evolutionary biology, including the generation of new phenotypes and occupation of previously unexploited environments; the nature of relationships among character change, ecology, and evolutionary rates; determinants of the geographic distribution of species and clades; and the underlying phylogenetic signal of ecological selectivity in extinctions and radiations. This is because phylogenetic paleoecology explicitly recognizes and incorporates the quasi-independent nature of evolutionary and ecological data as expressed in the dual biological hierarchies (Eldredge and Salthe 1984; Congreve et al. 2018; Fig. 1), incorporating both as covarying factors rather than focusing on one and treating the other as error within the dataset.


Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Jiaqi Tian ◽  
Chunsheng Fang ◽  
Jiaxin Qiu ◽  
Ju Wang

The increase in tropospheric ozone (O3) concentration has become one of the factors restricting urban development. This paper selected the important economic cooperation areas in Northeast China as the research object and collected the hourly monitoring data of pollutants and meteorological data in 11 cities from 1 January 2015 to 31 December 2019. The temporal and spatial variation trend of O3 concentration and the effects of meteorological factors and other pollutants, including CO (carbon monoxide), SO2 (sulfur dioxide), NO2 (nitrogen dioxide), and PM2.5 and PM10 (PM particles with aerodynamic diameters less than 2.5 μm and 10 μm) on ozone concentration were analyzed. At the same time, the variation period of O3 concentration was further analyzed by Morlet wavelet analysis. The results showed that the O3 pollution in the study area had a significant spatial correlation. The spatial distribution showed that the O3 concentration was relatively high in the south and low in the northeast. Seasonally, the O3 concentration was the highest in spring, followed by summer, and the lowest in winter. The diurnal variation of O3 concentration presented a “single peak” pattern. O3 concentration had a significant positive correlation with temperature, sunshine duration, and wind speed and a significant anticorrelation with CO, NO2, SO2, and PM2.5 concentration. Under the time scale of a = 9, 23, O3 had significant periodic fluctuation, which was similar to those of wind speed and temperature.


2018 ◽  
Vol 18 (2) ◽  
Author(s):  
Lorhaine Santos-Silva ◽  
Tamaris Gimenez Pinheiro ◽  
Amazonas Chagas-Jr ◽  
Marinêz Isaac Marques ◽  
Leandro Dênis Battirola

Abstract: Myriapods constitute important edaphic macrofauna taxa which dwell in different trophic levels and influence the dynamics of these environments. This study evaluated the variation in composition, richness and abundance of edaphic myriapod assemblages as a function of the distribution and structure of flooded and non-flooded habitats (spatial variation) and hydrological seasonality (temporal variation) in a floodplain of the northern Pantanal region of Mato Grosso, Brazil. Sampling was carried out in three areas of the Poconé Pantanal, along an altitudinal and inundation gradient consisting of inundated and non-inundated habitats and different vegetation formations. Three quadrats (10 x 10 m) were delimited within each habitat type, where sampling was performed using pitfall traps and mini-Winkler extractors during the dry, rising water, high water and receding water periods of two hydrological cycles within the Pantanal (2010/2011 and 2011/2012). A total of 549 millipedes were collected, consisting of 407 Diplopoda and 142 Chilopoda distributed in six orders, 12 families and 20 species. The assemblages composition varied throughout the seasonal periods, indicating that the rising water and dry periods differed from the high water and receding water periods. In addition to the variation between seasonal periods, myriapod richness and abundance also varied in relation to areas consisting of different vegetation formations. Thus, it can be concluded that the hydrological seasonality associated with the inundation gradient and different vegetation types were determinant in the heterogeneous spatial and temporal distribution of myriapod assemblages, validating that the conservation of these invertebrates in the Pantanal is directly linked to the preservation of vegetation, and consequently, ecosystem integrity.


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