Population ecology of the Asian house rat (Rattus tanezumi) in complex lowland agroecosystems in the Philippines

Context. Rattus tanezumi (the Asian house rat) is the principal rodent pest of rice and coconut crops in the Philippines. Little is known about the population and breeding ecology of R. tanezumi in complex agroecosystems; thus, current methods of rodent control may be inappropriate or poorly implemented. Aims. To investigate the habitat use, population dynamics and breeding biology of R. tanezumi in complex lowland agroecosystems of the Sierra Madre Biodiversity Corridor, Luzon, and to develop ecologically based rodent management (EBRM) strategies that will target specific habitats at specific times to improve cost-efficiency and minimise non-target risks. Methods. An 18-month trapping study was conducted in rice monoculture, rice adjacent to coconut, coconut groves, coconut-based agroforest and forest habitats. Trapped animals were measured, marked and assessed for breeding condition. Key results. Five species of rodent were captured across all habitats with R. tanezumi the major pest species in both the rice and coconut crops. The stage of the rice crop was a major factor influencing the habitat use and breeding biology of R. tanezumi. In rice fields, R. tanezumi abundance was highest during the tillering to ripening stages of the rice crop and lowest during the seedling stage, whereas in coconut groves abundance was highest from the seedling to tillering stage of nearby rice crops. Peaks in breeding activity occurred from the booting stage of the rice crop until just after harvest, but >10% of females were in breeding condition at each month of the year. Conclusions. In contrast with the practices applied by rice farmers in the study region, the most effective time for lethal management based on the breeding ecology of R. tanezumi is likely to be during the early stages of the rice crop, before the booting stage. Farmers generally apply control actions as individuals. We recommend coordinated community action. Continuous breeding throughout the year may necessitate two community campaigns per rice cropping season. To limit population growth, the most effective time to reduce nesting habitat is from the booting stage until harvest. Implications. By adopting EBRM strategies, we expect a reduction in costs associated with rodent control, as well as improved yield and reduced risk to non-target species.

Local spaces: open minds - inspirational ideas for managing lowland commons and other green spaces

The Chiltern commons are typical of those in the south east of England: small and numerous, but with the potential to provide important natural green space whilst contributing to environmental sustainability. In order to keep commons in good heart, they need to be managed. However, as activities such as grazing and coppicing become unviable on the commons, owners need to find sustainable roles beyond traditional agricultural and silvicultural practices. This paper examines ways of making management pay. It begins by exploring the economic, social and environmental challenges of sustainable management within the context of contemporary life. Section 2 identifies the different ways in which revenue contributions might be made towards the management of commons. Section 3 examines the relevant legal and other restrictions and Section 4 offers insights into where management proposals might offer multiple positive benefits, but also where there is the potential to cause conflict with environmental and social interests. Section 5 explores alternative funding streams for commons. Finally, Section 6 concludes with practical tips for the owners and managers of commons in the Chilterns and identifies areas for further research. Full references, links and resources are provided in the footnotes and appendix.

Landscape connectivity: a key to effective habitat restoration in lowland agricultural landscapes

Landscape scale habitat restoration has the potential to reconnect habitats in fragmented landscapes. This study investigates landscape connectivity as a key to effective habitat restoration in lowland agricultural landscapes and applies these findings to transferable management recommendations. The study area is the Stonehenge World Heritage Site, UK, where landscape scale chalk grassland restoration has been implemented. Here, the ecological benefits of landscape restoration and the species, habitat and landscape characteristics that facilitate or impede the enhancement of biodiversity and landscape connectivity were investigated. Lepidoptera were used as indictors of restoration success and results showed restoration grasslands approaching the ecological conditions of the target chalk grassland habitat and increasing in biodiversity values within a decade. Restoration success is apparent for four species with a broad range of grass larval host plants (e.g. Melanargia galathea, Maniola jurtina) or with intermediate mobility (Polyommatus icarus). However, two species with specialist larval host plants and low mobility (Lysandra bellargus), are restricted to chalk grassland fragments. Studies of restoration grassland of different ages show that recent grassland restoration (1 or 2 years old) may reduce the functional isolation of chalk grassland fragments. A management experiment showed that mowing increases boundary following behaviour in two species of grassland Lepidoptera; Maniola jurtina and Zygaena filipendulae. Analysis of the landscape scale implications of the grassland restoration illustrates an increase in grassland habitat network size and in landscape connectivity, which is likely to benefit the majority of grassland associated Lepidoptera. Landscape and habitat variables can be managed to increase the success of restoration projects including the spatial targeting of receptor sites, vegetation structure and selection of seed source and management recommendations are provided that are transferrable to other species-rich grassland landscape scale restoration projects. Overall results show restoration success for some habitats and species within a decade. However, additional management is required to assist the re-colonisation of specialist species. Despite this, habitat restoration at the landscape scale can be an effective, long term approach to enhance butterfly biodiversity and landscape connectivity.

Modelling primary producer interaction and composition: an example of a UK lowland river

Nutrient enrichment and drought conditions are major threats to lowland rivers causing ecosystem degradation and composition changes in plant communities. The controls on primary producer composition in chalk rivers are investigated using a new model and existing data from the River Frome (UK) to explore abiotic and biotic interactions. The growth and interaction of four primary producer functional groups (suspended algae, macrophytes, epiphytes, sediment biofilm) were successfully linked with flow, nutrients (N, P), light and water temperature such that the modelled biomass dynamics of the four groups matched that of the observed. Simulated growth of suspended algae was limited mainly by the residence time of the river rather than in-stream phosphorus concentrations. The simulated growth of the fixed vegetation (macrophytes, epiphytes, sediment biofilm) was overwhelmingly controlled by incoming solar radiation and light attenuation in the water column. Nutrients and grazing have little control when compared to the other physical controls in the simulations. A number of environmental threshold values were identified in the model simulations for the different producer types. The simulation results highlighted the importance of the pelagic–benthic interactions within the River Frome and indicated that process interaction defined the behaviour of the primary producers, rather than a single, dominant driver. The model simulations pose interesting questions to be considered in the next iteration of field- and laboratory based studies.

STRUCTURE OF THE SHRUB-ARBOREAL COMPONENT OF AN ATLANTIC FOREST FRAGMENT ON A HILLOCK IN THE CENTRAL LOWLAND OF RIO DE JANEIRO, BRAZIL

The present study describes and evaluates the horizontal and vertical structures of a lowland forest fragment on a hillock in the municipality of Silva Jardim, Rio de Janeiro State, Brazil (22 degrees 31`56 `` S and 42 degrees 20`46 `` W). Twenty plots (10x2m) totaling 0.5ha were laid out following the slope grade using DBH >= 5cm as the inclusion criterion. A total of 734 individuals were encountered, yielding a total density of 1468 ind./ha and a total basal area of 10783m(2). The richness values (129 species/41 families), Shannon-Wiener diversity (4.22) and equitability (0.87) indices indicated an accentuated floristic heterogeneity and low ecological dominance. Lauraceae, Myrtaceae, Fabaceae and Euphorbiaceae showed the greatest species richness, corroborating other studies that indicated these species as the most representative of Atlantic Forest areas in southeastern Brazil. The species with the greatest importance values (VI) were Aparisthmium cordatum, Guapira opposita, Lacistema pubescens, Xylopia sericea, Tapirira guianensis and Piptocarpha macropoda. The high diversity observed was influenced by earlier anthropogenic actions and by the current successional stage. The forest fragment studied demonstrated closer floristic similarity to areas inventoried in a close-by biological reserve than to fragments dispersed throughout the coastal plain. Similarities in soil type, degree of soil saturation and use-history of forest resources all support these relationships. The fragmented physiognomy of the central lowland in this region and the use-history of the landscape make these small remnant forest areas important in terms of establishing strategies for landscape restoration and species conservation.

Out of Amazonia again and again: episodic crossing of the Andes promotes diversification in a lowland forest flycatcher

Most Neotropical lowland forest taxa occur exclusively on one side of the Andes despite the availability of appropriate habitat on both sides. Almost all molecular phylogenies and phylogenetic analyses of species assemblages (i.e. area cladograms) have supported the hypothesis that Andean uplift during the Late Pliocene created a vicariant barrier affecting lowland lineages in the region. However, a few widespread plant and animal species occurring in lowland forests on both sides of the Andes challenge the generality of this hypothesis. To understand the role of the Andes in the history of such organisms, we reconstructed the phylogeographic history of a widespread Neotropical flycatcher (Mionectes oleagineus) in the context of the other four species in the genus. A molecular phylogeny based on nuclear and mitochondrial sequences unambiguously showed an early basal split between montane and lowland Mionectes. The phylogeographic reconstruction of lowland taxa revealed a complex history, with multiple cases in which geographically proximate populations do not represent sister lineages. Specifically, three populations of M. oleagineus west of the Andes do not comprise a monophyletic clade; instead, each represents an independent lineage with origins east of the Andes. Divergence time estimates suggest that at least two cross-Andean dispersal events post-date Andean uplift.

Boron adsorption in lowland soils from Parana State, Brazil

Boron adsorption by soil is the main phenomenon that affects its availability to plants. This, the present study investigated the effect of liming on B adsorption by lowland soils of Parana State, and to correlate these values with the physical and chemical properties of the soils. Surface samples of three lowland soils [Gleissolo Haplico (GX), Plintossolo Haplico (FX) and Cambissolo Haplico (CX)], with different origin material and physicochemical properties were used. Samples with or without liming application were incubated during 60 days. Boron adsorption was accomplished by shaking 4.0g soil samples, for 24 h, with 20 mL of 0.01 mol L-1 CaCl2 solution containing different concentrations of B (0, 1, 2, 4, 8 and 16 mg L-1). Sorption was fitted to non-linear form of the Langmuir adsorption isotherm. The adsorption isotherms indicated that the B adsorption increased with its increasing concentration in the equilibrium solution. Maximum adsorption capacity of B ranged from 3.0 to 13.9 mg kg(-1) (without liming) and 14.7 to 35.7 mg kg(-1) (with liming). Liming increased the amount of adsorbed B in Gleissolo Haplico and Plintossolo Haplico soils, although the bonding energy has decreased. The amount of adsorbed B by Cambissolo Haplico soil was not affected by liming application. The most important soil properties affecting the B adsorption in lowland soils were pH, clay content, exchangeable aluminum and iron oxide contents.

Horizontal and vertical tree community structure in a lowland atlantic rain forest, southeastern Brazil

A estrutura horizontal e vertical do componente arbóreo foi investigada em um trecho de Floresta Atlântica baixo-montana através de um levantamento fitossociológico em dois blocos amostrais de 0,99 ha cada no Parque Estadual Intervales. Todos os indivíduos com DAP > 5 cm foram registrados. Foram amostrados 3.078 indivíduos distribuídos em 172 espécies. O índice de diversidade de Shannon foi de H' = 3,85 nat.ind.-1. A família Myrtaceae se destacou tanto em número de espécies (38) quanto em número de indivíduos (745) no levantamento. Euterpe edulis Mart. teve o maior valor de importância (33,98%), abrangendo 21,8% do total de indivíduos registrados. O índice de similaridade quantitativo foi maior do que o qualitativo, mostrando pouca variação estrutural entre os blocos amostrais, mas a grande quantidade de espécies pouco abundantes, resultou em pronunciadas diferenças florísticas entre eles. Uma análise de correspondência retificada (DCA) gerou três estratos verticais arbitrários. O estrato A (> 26 m) teve a menor densidade e foi bem representado pelas espécies Sloanea guianensis (Aubl.) Benth. e Virola bicuhyba (Schott. ex A.DC.) Warb. O estrato B (8 m < h < 26 m) mostrou a maior riqueza e diversidade florística, e o estrato C (< 8 m) a maior densidade. Euterpe edulis, Guapira opposita (Vell.) Reitz, Garcinia gardneriana (Planch. & Triana) Zappi e Eugenia mosenii (Kausel) Sobral foram bem representadas nos estratos B e C da floresta. A existência de estratos verticais em florestas tropicais é discutida, recomendando-se o uso da DCA para estudos da estratificação vertical em outras florestas tropicais.

Parrot populations and habitat use in and around two lowland Atlantic forest reserves, Brazil

We estimated population sizes of parrots in a large (Sooretama/Linhares) and a small (Porto Seguro) lowland Atlantic forest reserve, and examined their habitat associations within the reserves, and their use of forest fragments. In Sooretama, most species had estimated populations between 1000 and 20,000 individuals, but in the smaller reserve population densities were low and all but one species had population estimates < 500. Two Amazons, including the 'Endangered' Amazona rhodocorytha, were strongly linked to primary forests whereas the 'Vulnerable' Pyrrhura cruentata was associated with non-pristine forest. There was considerable movement of parrots between the Sooretama reserve and the surrounding country with Amazona species tending to fly into the reserve during the mornings, and the macaw Propyrrhura maracana flying out. Other species, notably P. cruentata and P. leucotis, were never recorded away from the reserve. Most parrot populations in the region are likely to be small, and the substantial populations around Sooretama make this reserve a parrot stronghold. It is crucial that fire, illegal logging and parrot capture are adequately controlled within Sooretama, and there is a strong argument for extending conservation management efforts to areas immediately outside the reserve. (C) 2000 Elsevier B.V. Ltd. All rights reserved.

Wildlife forensic DNA and lowland tapir (Tapirus terrestris) poaching

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microsatellite loci isolated from the lowland tapir (Tapirus terrestris), one of the largest Neotropical mammal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of forest cover and mesohabitat types on functional and taxonomic diversity of fish communities in Neotropical lowland streams

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A fish-based biotic integrity index for assessment of lowland streams in southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Post partum reproductive assessment in lowland Tapir (Tapirus terrestris): a case report

O tapir ou anta, descrito como o maior mamífero terrestre brasileiro, pertence à ordem Perissodactila, subordem Hippomorfa, superfamília Tapiroidea e família Tapiridae. Na floresta úmida está envolvido com a dispersão de sementes em função das características do tubo digestivo. O acompanhamento do ciclo estral permite avaliar e compreender a atividade reprodutiva nas espécies animais. Nos animais silvestres, o estresse da contenção pode interferir na própria ciclicidade gonadal, uma das alternativas é o acompanhamento dos hormônios gonadais nas excretas. Buscamos neste trabalho o acompanhamento periódico da atividade gonadal através da quantificação de progesterona no leite. Utilizamos uma fêmea recém-parida no Zoológico de Araçatuba, da qual colhemos leite, esfregaço vaginal e temperatura retal. A progesterona foi quantificada por radioimunoensaio de fase sólida (Coat-a-Count, DPC®) com curva padrão fornecida pela F.A.O. O ensaio mostrou sensibilidade de 1,25 nmol/l com coeficiente de variação intra-ensaio de 15,36%. Durante a fase de lactação, a fêmea não apresentou níveis detectáveis de progesterona por 158 dias (de novembro a abril). O primeiro pico de produção foi de 2,3 nmol/l e apresentou duração de 5 dias. O segundo pico de 3,54 nmol/l teve uma duração de 23 dias. Setenta e quatro dias após o aparecimento da progesterona no leite a lactação cessou. Podemos concluir que a fêmea de tapir apresentou um período de anestro lactacional de aproximadamente 5 meses e voltou a ciclar no outono (abril) sugerindo pouca influência do fotoperíodo. A quantificação da progesterona no leite mostrou-se útil para o acompanhamento do ciclo estral na espécie, porém a variação da citologia vaginal e temperatura retal não apresentaram correlação com os níveis hormonais.