摘要:

AbstractVertical litterfall and lateral litter movement were monitored in the riparian zone of Birthday Creek, a small upland rainforest stream in north Queensland, from June 1987 to May 1990. Total litterfall (mean = 484 g m−2year‐1) was low in comparison with other tropical sites both within Australia and elsewhere. Litterfall was distinctly seasonal, with maxima occurring in the spring (October‐November) and minima in winter (June–July). Tropical storms caused short‐term increases in litterfall, especially of the small wood fraction. Overall, laterally transported litter contributed 6.8% of the total litter input to the monitored section of the stream. Lateral movement varied according to bank slope and microtopographic features and was not related to wind. Nitrogen and phosphorus concentration of leaves were low (mean N= 1.26%, P = 0.029% by weight). Nitrogen concentration of laterally transported levels overall was about 19% higher than that of leaves falling directly into t

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00465.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe collembolan faunas of 30 bauxite mines rehabilitated by a range of different methods between 1966 and 1977, and three forest plots were surveyed in the spring and summer of 1978–79 with the aim of studying the restoration of decomposer activity in degraded areas. The rehabilitation methods included seeding and planting with a variety of native or exotic plant species. Physical and botanical parameters of the plots were also measured. Sixty species of Collembola were collected from the rehabilitated areas; nine of the 28 species found in the forest plots were not present on the mined sites. Principal components analysis suggested that the species richness of the collembolan community in rehabilitated areas is positively correlated with plot age. A parametric correlation analysis using a number of collembolan community characteristics revealed that, among other factors, the development of a species rich collembolan fauna is positively correlated with plant species richness and diversity, and also with percentage plant cover. These results provide directions for improving rehabilitation practice

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00466.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractEstimates of the population size of black noddyAnous minutuson Heron Island were made by counting nests in permanently marked plots inPisonia grandisforest in 1978, 1979 and 1992. The results, and published data, indicate that the population has been increasing at ca 7% per annum since early this century and currently isca63 000 ± 7000 pairs. The continued exponential increase in bird numbers poses interesting ecological questions and potential management problems, as more of the island is occupied by the birds and interaction with the vegetation intensifies.Pisoniais by far the most common tree on the island and most nests are in this species. However, there is evidence thatFicus oppositais preferred overPisoniaand the high mortality of this species in the marked plots may be due to excessive use by noddies.Pisoniatrees which reach the forest canopy and are in the 40–60 cm stem diameter class have more nests than smaller trees. Larger stems (>60 cm diameter) are also underutilized relative to their size, and it is suggested that this is because they are more liable to windthrow in cyclon

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00467.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractEleven sites, representing different successional stages ofEucalyptus regnans‐dominated forest in the Central Highlands of Victoria, were selected to identify potentially important habitat variables for heliothermic reptiles, three species (Eulamprus tympanum, Niveoscincus coventryi, Pseudemoia spenceri) of which were common at these sites. Analyses reveal that many forest attributes are strongly correlated with stand age and that some are significant habitat variables for some of these species. ‘One‐at‐a‐time’ modelling of habitat variables reveals that counts ofE. tympanumare most strongly correlated with the proportion of grass as substrate (−ve), moss cover of logs (−ve) and litter depth (+ ve);N. coventryicounts are most significantly related to litter depth (−ve), numbers of logs (−ve), log diameter (−ve), the proportion of bare ground as substrate (−ve) and length of sunny patches (+ ve);P. spencericounts are most significantly related to the number of sunny patches (−ve) and moss cover of logs (−ve). The total reptile count is most significantly correlated with stag diameter (−ve) and log diameter (−ve). Predictive equations for each of the common species are also presented, using measured habitat variables, and these, along with ‘one‐at‐a‐time’ models, indicate that a number of factors determine reptile occurrence or abundance and that

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00468.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractPotential hosts had no effect on seed germination of the mistletoes,Amyema preissiiandLysiana exocarpi, but affected seedling holdfast formation and leaf emergence. ForA. preissii, formation of the holdfast and emergence of leaves occurred most rapidly in seedlings on its usual host,Acacia nyssophylla. Among the six species inoculated withL. exocarpiseeds, formation of the holdfast was quickest onA. nyssophyllaandMyoporum platycarpum(usual hosts). Emergence of leaves was quickest in seedlings onA. nyssophylla, and on two non‐hosts,Eucalyptus oleosaandExocarpos aphyllus. For both mistletoe species, seedling mortality was high during the first 3 months, with considerable variation among different host species. After 6 months, little or no mortality was recorded on seedlings growing on their usual hosts. In contrast, seedlings on non‐host species suffered continuing mortality and none survived the study period, except for 13% of theL. exocarpiseedlings, which persisted onGeijera linearifoliain a moribund state.The growth of seedlings on host and non‐host species varied markedly. After 35 and 47 months, the average length of the longest shoot of two cohorts ofA. preissiiseedlings was 22 and 75 cm, respectively. After 47 months, the average length of the longest shoot ofL. exocarpiseedlings onA. nyssophylla, H. oleifoliumandM. platycarpumwas 57, 38 and 41 cm, respectively. For both mistletoe species, a proportion of individuals on host species flowered and subsequently set fruits within 3 years. In comparison, none of the plants sown on the non‐host species grew beyond seedling stage. The inability ofA. preissiiandL. exocarpito establish on non‐host species was attributed to mistletoe‐host inco

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00469.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe herpetofauna of 50 monsoon rainforest patches in the Top End of the Northern Territory was surveyed during the dry season of 1990. This fauna contains few obligate monsoon rainforest species, many species which favour this habitat as part of a broad habitat range and a large number of species (indeed most of the regional species pool) that occasionally occur within monsoon rainforests. The taxonomic composition of species favouring monsoon rainforests is a non‐random selection from the regional pool, with relatively few species in the families Agamidae and Scincidae occurring commonly in monsoon rainforests.Environmental variation among the rainforest patches sampled was portrayed by ordination, with the first axis corresponding to an environmental gradient from coastal sites to inland rocky rainforests and the second a gradient from relatively dry thickets to tall dense rainforests close to water. The distributions of herpetofauna species were depicted on this ordination space. Most frog species occurred in relatively wet rainforests and most gecko species were relatively restricted to drier rainforests. A substantial component of the herpetofauna was associated with rainforests on rocky substrate.In contrast to this relatively good association with these defined gradients, there was little apparent influence of patch size or level of disturbance on the distribution of individual species of herpetofauna. Sampling month was related to the abundance of many species, with many frog species and some snake and skink species declining (but some skink and one frog species increasing) in abundance in rainforest patches during the late dry season. This seasonal change in abundance is not due to movements from rainforest patches to adjacent vegetation types (or vice versa) but rather to total landscape (cross‐habitat) changes in abundance (or detectability).The species composition of patches tended to be idiosyncratic, with substantial variability in composition, even between nearby patches of like environment. Hence it is not possible to nominate a representative rainforest herpetofauna, and indeed a classification of all quadrats (including those from rainforests, rainforest edges and adjacent habitats) based on herpetofauna species composition grouped many non‐rainforest quadrats with those from rainforests. There was no rainforest edge herpetofauna assemblage.The herpetofauna from rainforests of the Northern Territory was similar to but somewhat richer than that recorded from the even more attenuated monsoon rainforest area of the Kimberley of northwestern Australia, but shared relatively few species with a sampling from monsoon rainforests from western Cape York. Frog species were more likely to be recorded across these three regions than were snake species.The number of herpetofaunal species per patch was low compared to tropical forests in northeastern Australia, Asia and central America. The long dry season of the Top End may contribute to this impoverishment. However, the small total area of monsoon rainforests in this region, the current scattered network of patches and historical fluctuations in extent and distribution of this habitat are probably at least as impo

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00470.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThree habitats, each containing a different form (rainforest, coastal and dry tropics) of the twining vineTinospora smilacina, and a fourth with two of these forms were routinely sampled between 1986 and 1989 for larvae of fruitpiercing moths, to ascertain spatial and temporal utilization of this plant.Othreis fulloniaandOthreis maternaoccurred on all forms in all habitats, predominantly between November and March for the former and January to June for the latter. AlthoughRhytia cocalusutilized two forms ofT. smilacinait preferred the rainforest habitat to whichOthreis jordaniandKhadira aurantiawere essentially confined. While the degree of cohabitation between any two moth species was greatest in the drier inland habitat, where onlyO. maternaandO. fulloniaoccurred during a limited season, there was considerable temporal separation of any two species utilizingT. smilacinain any habitat. Field and laboratory evaluation of alternative menisperm hosts suggestedO. fullonia, O. jordaniandK. aurantiawere generalists whileO. maternaandR. cocalusconfined their feeding to the genusTinospora. The differential habitat affinities and host plant acceptance of these moths are pertinent to their variable seasonal activity, local importance and general pest status.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00471.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractRainforest patches in the Australian wet‐dry tropics occur as habitat islands. Recent studies show that many patches are severely damaged by feral animals, weed invasion and contemporary fire regimes. This paper documents the status of an endangered palm species,Ptychosperma bleeseri, which occurs within a narrow geographical range in seven rainforest patches. Results of multivariate statistical analysis of quadrats with and withoutP. bleeserishow that the species does not appear to occupy all suitable habitat available at either a regional scale or within single rainforest patches. Evidence, based on demographic surveys, is presented for the current decline ofP. bleeseripopulations and possible causes for this decline are discussed; in particular, the impacts of wildfire and feral animal activity. Recommendations for a recovery plan for P. bleeseri are discussed, and include fencing, fire protection and public educatio

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00472.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00473.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Book reviews in this article:Comparative Ecology of Microorganisms and MacroorganismsJ. H. Andrews.Infectious Diseases of HumansR. M. Anderson and R. M. May.Growback '91Edited by T. Offor and R. J. Watson.The Tinbergen LegacyEdited by M. S. Dawkins, T. R. Halliday and R. Dawkins.

ISSN:0307-692X    

DOI:10.1111/j.1442-9993.1993.tb00474.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY