Can a native rodent species limit the invasive potential of a non-native rodent species in tropical agroforest habitats?

BACKGROUND Little is known about native and non-native rodent species interactions in complex tropical agro-ecosystems. We hypothesised that the native non-pest rodent Rattus everetti may be competitively dominant over the invasive pest rodent Rattus tanezumi within agroforests. We tested this experimentally by using pulse removal for three consecutive months to reduce populations of R. everetti in agroforest habitat and assessed over 6-months the response of R. tanezumi and other rodent species. RESULTS Following removal, R. everetti individuals rapidly immigrated into removal sites. At the end of the study period, R. tanezumi were larger and there was a significant shift in their microhabitat use with respect to the use of ground vegetation cover following the perturbation of R. everetti. Irrespective of treatment, R. tanezumi selected microhabitat with less tree canopy cover, indicative of severely disturbed habitat, whereas, R. everetti selected microhabitat with a dense canopy. CONCLUSION Our results suggest that sustained habitat disturbance in agroforests favours R. tanezumi, whilst the regeneration of agroforests towards a more natural state would favour native species and may reduce pest pressure in adjacent crops. In addition, the rapid recolonisation of R. everetti suggests this species would be able to recover from non-target impacts of short-term rodent pest control.

Can agroforest woodlots work as stepping stones for birds in the Atlantic forest region?

In fragmented landscapes, agroforest woodlots can potentially act as stepping stones facilitating movement between forest fragments. We assessed the influence of agroforest woodlots on bird distribution and diversity in the Atlantic forest region (SE Brazil), and also tested which categories of species can use different types of connection elements, and whether this use is influenced by the distance to large forest patches. We studied two fragmented landscapes, with and without stepping stones linking large fragments, and one forested landscape. Using a point count, a bird survey was undertaken in the fragmented landscapes in five different elements: large remnants (> 400 ha), agroforest woodlots (0.4-1.1 ha), small patches (0.5-7 ha), riparian corridor, and pasture areas (the main matrix). Generalist and open-area species were commonly observed in the agroforest system or other connection elements, whereas only a few forest species were present in these connections. For the latter species, the distance of woodlots to large patches was essential to determine their richness and abundance. Based on our results and data from literature, we suggest that there is an optimal relationship between the permeability of the matrix and the efficiency of stepping stones, which occurs at intermediate degrees of matrix resistance, and is species-dependent. Because the presence of agroforest system favors a higher richness of generalist species, they appeared to be more advantageous for conservation than the monoculture system; for this reason, they should be considered as a management alternative, particularly when the matrix permeability requirement is met.

Resource use pattern and agroecosystem functioning in Rawanganga micro-watershed in Garhwal Himalaya, India

Agro-ecological resource use pattern in a traditional hill agricultural watershed in Garhwal Himalaya was analysed along an altitudinal transect. Thirty one food crops were found, although only 0.5% agriculture land is under irrigation in the area. Fifteen different tree species within agroforestry systems were located and their density varied from 30-90 trees/ha. Grain yield, fodder from agroforest trees and crop residue were observed to be highest between 1200 and 1600 m a.s.l. Also the annual energy input- output ratio per hectare was highest between 1200 and 1600 m a.s.l. (1.46). This higher input- output ratio between 1200-1600 m a.s.l. was attributed to the fact that green fodder, obtained from agroforestry trees, was considered as farm produce. The energy budget across altitudinal zones revealed 95% contribution of the farmyard manure and the maximum output was in terms of either crop residue (35%) or fodder (55%) from the agroforestry component. Presently on average 23%, 29% and 41% cattle were dependent on stall feeding in villages located at higher, lower and middle altitudes respectively. Similarly, fuel wood consumption was greatly influenced by altitude and family size. The efficiency and sustainability of the hill agroecosystem can be restored by strengthening of the agroforestry component. The approach will be appreciated by the local communities and will readily find their acceptance and can ensure their effective participation in the programme.

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.

Landscape and farm scale management to enhance biodiversity conservation in the cocoa producing region of southern Bahia, Brazil

In southern Bahia, Brazil, large land areas are used for the production of cocoa (Theobroma cacao), which is predominantly grown under the shade of native trees in an agroforestry system locally known as cabruca. As a dominant forest-like landscape element of the cocoa region, the cabrucas play an important role in the conservation of the region`s biodiversity. The purpose of this review is to provide the scientific basis for an action plan to reconcile cocoa production and biodiversity conservation in southern Bahia. The available research collectively highlights the diversity of responses of different species and biological groups to both the habitat quality of the cabrucas themselves and to the general characteristics of the landscape, such as the relative extent and spatial configuration of different vegetation types within the landscape mosaic. We identify factors that influence directly or indirectly the occurrence of native species in the cabrucas and the wider landscape of the cocoa region and develop recommendations for their conservation management. We show that the current scientific knowledge already provides a good basis for a biodiversity friendly management of the cocoa region of southern Bahia, although more work is needed to refine some management recommendations, especially on shade canopy composition and density, and verify their economic viability. The implementation of our recommendations should be accompanied by appropriate biological and socioeconomic monitoring and the findings should inform a broad program of adaptive management of the cabrucas and the wider cocoa landscape.

Conservation in tropical landscape mosaics: the case of the cacao landscape of southern Bahia, Brazil

A recent debate has contrasted two conservation strategies in agricultural landscapes; either ""land sparing`` farm development combining intensive production practices with forest set-asides, or ""wildlife-friendly`` farming with greater on-farm habitat value but lower yields. We argue that in established mosaic landscapes including old cacao production regions where natural forest has already been reduced to relatively small fragments, a combination of both strategies is needed to conserve biodiversity. After reviewing the evidence for the insufficiency of either strategy alone if applied to such landscapes, the paper focuses on the cacao production landscape of southern Bahia, Brazil, once the world`s second largest cacao producer. Here, small remaining areas of Atlantic Forest are embedded in a matrix dominated by traditional cacao agroforests, resulting in a landscape mosaic that has proven favorable to the conservation of the region`s high biodiversity. We show that current land use dynamics and public policies pose threats but also offer opportunities to conservation and describe a three- pronged landscape conservation strategy, consisting of (i) expansion of the protected areas system, (ii) promotion of productive yet biodiversity-friendly cacao farming practices, and (iii) assistance to land users to implement legally mandated on-farm reserves and voluntary private reserves. We discuss recent experiences concerning the implementation of this strategy, discuss likely future scenarios, and reflect on the applicability of the Bahian experience to biodiversity rich cacao production regions elsewhere in the tropics.

Construção de um inclinômetro para avaliar o efeito da declividade lateral no desempenho de tratores agrícolas

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Uso do território, experiências inovadoras e sustentabilidade: um estudo em unidades de produção familiares de agricultores/as na área de abrangência do Programa PROAMBIENTE, Nordeste Paraense

Este estudo avaliou a sustentabilidade das experiências inovadoras baseadas em indicadores e critérios fundamentados em teorias científicas pela percepção de agricultores/as dos municípios de Irituia, São Domingos do Capim, Concórdia do Pará e Mãe do Rio na área de abrangência do Pólo Rio Capim do programa PROAMBIENTE. Objetivou-se compreender o cotidiano desses atores sociais no uso do território por meio de práticas de mínimo impacto ambiental e os motivos que os levaram a estender os tradicionais sitos ou quintais para outras parcelas das Unidades de Produção Familiares (UPFs), transformando-as em Sistemas Agroflorestais (SAFs). A metodologia adotada compreendeu na construção de um formulário, a coleta de dados empíricos e convívio direto em 78 UPFs o que permitiu a identificação de constructo de variabilidade pela Análise Fatorial, estabelecendo quatro fatores: produção e comercialização; prática de produção; intervenção e questão de gênero. O primeiro fator foi utilizado como critério para a seleção e retorno em 18 UPFs definidas para aplicar o questionário e o formulário de notas avaliativas referentes aos indicadores econômicos, social, cultural e ecológico-ambiental. A avaliação da sustentabilidade foi feita por meio da consolidação destes indicadores utilizando o método agroecológico da “Ameba” e o mapeamento da mesma pelo método de interpolação do “vizinho mais próximo” na área de estudo. Como resultados aos indicadores cultural e ecológico/ambiental, apresentaram-se em melhores condições em termos de sustentabilidade com a conceituação de bom para excelente, enquanto que Inversamente foi a situação demonstrada pelos indicadores social e econômico, dos quais os resultados avaliados estão no limiar do que se pode deduzir como sustentável com desempenho de fraco para suficiente.

Comportamento silvicultural e dinâmica de serapilheira em plantios de duas espécies florestais na Amazônia oriental brasileira

O desmatamento na Amazônia brasileira já alterou cerca de 750 milhões de hectares e desse total, 20% encontra-se com algum nível de degradação. A reincorporação ao processo produtivo das áreas alteradas com o reflorestamento de espécies tropicais, de valor comercial, é uma alternativa para minimizar os impactos ambientais, com benefícios ecológicos, aumento da oferta de madeira e diminuição da pressão sobre as florestas naturais remanescentes. No entanto, um dos grandes empecilhos para o reflorestamento é a falta de conhecimentos científicos sobre o crescimento de espécies nativas e exóticas. Diante disto, este trabalho teve como objetivo avaliar a eficiência de diferentes sistemas de plantios com espécies florestais nativa e exótica para recuperação de áreas alteradas. O trabalho foi realizado no município de Dom Eliseu, estado do Pará, em três sistemas de uso da terra: plantio puro (Schizolobium parahyba var. amazonicum e Khaya ivorensis), consórcio de espécies florestais (S. parahyba var. amazonicum e Khaya ivorensis), sistema agroflorestal (S. parahyba var. amazonicum e Musa sp). Aos 40 meses de idade, em plantio homogêneo, Schizolobium parahyba var. amazonicum mostrou maior crescimento silvicultural (altura e diâmetro) no espaçamento 4 m x 3 m e Khaya ivorensis no espaçamento 4 m x 4 m. No entanto, o paricá apresentou melhor desempenho em sistema de consórcio e sistema agroflorestal. O melhor desempenho de K. ivorensis foi no consórcio de espécies. Entre os sistemas de plantio estudados (SAF e misto de espécies), a deposição de biomassa foi maior no sistema de consórcio de espécies com 3.737,5 kg ha^-1, sendo que, a maior contribuição de material vegetal foi do paricá. Foi evidenciada correlação negativa entre a deposição de serapilheira e a precipitação pluviométrica para o paricá, e positiva para K. ivorensis. Os resultados obtidos mostraram que o modelo florestal de consórcio de espécies mostrou-se promissor e pode ser uma alternativa para recuperação de áreas alteradas, de modo a oferecer diferentes opções de madeira e ao mesmo tempo, agregar fatores positivos em relação a produção de biomassa e aspectos físico-químicos do solo.

Carências de boro no interior - norte e centro - de Portugal

In Portugal, boron deficiency has been observed almost everywhere, in particular in the interior of the country, causing severe crop damage. In the 1950’s, the growth anomalies in the Douro vineyards were recognised as a boron deficiency (called ´maromba’). From the 1980’s onwards systematic studies have been carried out in the northern and central interior of Portugal with the purpose of identifying and correcting this deficiency in fruit trees and forest/agroforest species. In this review paper an inventory of geological/lithological formations and soil groups is carried out where the boron shortage was most often detected. The environmental conditions that enhanced the occurrence of boron deficiency were reviewed. Based on studies carried out in these regions, the deficiency symptoms of selected trees were described, and also the boron concentrations in soils and leaves in which the symptoms had been observed were recorded. Experimental results of boron fertilisation in terms of growth or yield increase of crops were presented. Finally, an attempt is made to explain perplexities arisen from unexpected plant reactions, either due to the deficiency or to boron application, since the emergence of ´maromba’ in the 19th century until the present. In addition, some strategies for correction of scarcity of this micronutrient are suggested

Overgrazing in the Montado? The need for monitoring grazing pressure at paddock scale

Montados are presently facing the threat of either abandonment or intensification, and livestock overgrazing has been suspected of contributing to reduced natural regeneration and biodiversity. However, reliable data are to our knowledge, lacking. To avoid potential risks of overgrazing, an adaptive and efficient management is essential. In the present paper we review the main sources of complexity for grazing management linked with interactions among pasture, livestock and human decisions. We describe the overgrazing risk in montados and favour grazing pressure over stocking rate, as a key indicator for monitoring changes and support management decisions. We suggest the use of presently available imaging and communication technologies for assessing pasture dynamics and livestock spatial location. This simple and effective tools used for monitoring the grazing pressure, could provide an efficient day-to-day aid for farm managers’ operational use and also for rangeland research through data collection and analysis.

The women role in the agroenvironmental activities of Amazon agroforeststry systems.

This paper presents the results of a research on the way which shows the role of the farmer women to contribute to overcome the life hindrances in the Amazonian agroforest environment, for food safety and familiar income. The sample was the women of the Associação de Produtores Alternativos - APA, Ouro Preto do Oeste, Rondônia, Brazil. Questionnaires were applied to 50 women of this community, in 2004/2005, with additional interviews in 2006, taking into account their role in the farms, and their several invisible activities. The role of APA?s women was compared to that of other Amazonian women, like rubber tappers and riverine people. The APA?s women perform tasks as field manpower - 78.0% of them, making decisions about what to plant - 18.0%, harvest destination - 32.0%, which animals to raise -14.0% and animal products destination -34.0%. Traditionally, in rural zone, the women with their children play a role as non-paid manpower, getting some monetary income with occasional commercialization of on-farm processed products as cheese, pickles, jellies and fruit liqueurs. They are responsible for the cultures practiced around the house. All these Amazonian women edaphoclimatic conditions, greatly contributing to the biodiversity, conservation, and to ecological, social and economic stability.are guardians, perpetuators and disseminators of a rich germplasm adapted to local.

Agriculture and forest: A sustainable strategy in the Brazilian Amazon.

Large-scale agriculture is increasing in anthropogenically modified areas in the Amazon Basin. Crops such as soybean, maize, oil palm, and others are being introduced to supply the world demand for food and energy. However, the current challenge is to enhance the sustainability of these areas by increasing efficiency of production chains and to improve environmental services. The Amazon Basin has experienced a paradigm shift away from the traditional slash-and-burn agricultural practices, which offers decision makers the opportunity to make innovative interventions to enhance the productivity in previously degraded areas by using trees to ecological advantage. This study describes a successful experiment integrating the production of soybean and paricá (Glycine max L. and Schizolobium amazonicum) based on previous research that indicated potential topoclimatic zones for planting paricá in the Brazilian state of Pará. This paper shows that a no-tillage system reduces the effects of drought compared to conventional tillage still used by many farmers in the region. The integrated system was implemented during the 2014/2015 season in 234.6 ha in the high-potential zone in the municipality of Ulianópolis, Pará. Both soybean and paricá were planted simultaneously. Paricá was planted in 5 m x 2 m inter-tree spacing totaling 228x103 trees per hectare and soybean, in 4 m x 100 m spacing, distributed in nine rows with a 0.45 m inter-row distance, occupying 80% of the area. The harvested soybean production was 3.4 t ha-1, higher than other soybean monocultures in eastern Pará. Paricá benefited from soybean fertilization in the first year: It exhibited rapid development in height (3.26 m) and average diameter (3.85 cm). Trees and crop rotation over the following years is six years for forest species and one year for each crop. Our results confirm there are alternatives to the current production systems able to diminish negative impacts resulting from monoculture. In addition, the system provided environmental services such as reduced soil erosion and increased carbon stock by soil cover with no-tillage soybean cultivation. The soybean cover contributes to increased paricá thermal regulation and lower forestry costs. We concluded that innovative interventions are important to show local farmers that it is possible to adapt an agroforest system to large-scale production, thus changing the Amazon.