Percepção dos enfermeiros gestores da atenção primária sobre o processo de enfermagem / Percepción de directores de la enfermera de salud primaria en el proceso de enfermería / Perception of primary healthcare management nurses on the nursing process

RESUMO Objetivo: analisar a percepção dos enfermeiros gestores da atenção primária à saúde sobre o processo de enfermagem. Método: estudo qualitativo em que os dados foram coletados por meio de entrevistas e analisados a partir da Análise de Conteúdo proposta por Bardin. Resultados: os gestores reconhecem a importância do processo de enfermagem, embora sua implementação não seja prioridade no momento. Existe dificuldade conceitual e não compreensão de que a implementação da metodologia de assistência deva perpassar pela gestão municipal. Conclusão: necessita-se de ampliação da visão dos gestores quanto à importância do processo de enfermagem e qualificação dos profissionais. Acredita-se na participação ativa dos órgãos legisladores de enfermagem, gestão local de saúde e governo federal para que a implementação do processo de enfermagem seja viabilizada. .

RESUMEN Objetivo: analizar las percepciones de los gerentes de enfermería de atención primaria de salud en el proceso de enfermería. Métodos: estudio cualitativo; los datos fueron recolectados a través de entrevistas y analizados desde el Análisis de Contenido propuesta por Bardin referencial teórico. Resultados: los gerentes reconocen la importancia del proceso de enfermería, aunque su aplicación no es la prioridad en este momento. No hay ninguna dificultad conceptual y la comprensión de que la ejecución de la ayuda metodología debe impregnar la gestión municipal. Conclusión: es necesario ampliar la visión de los administradores en cuanto a la importancia del proceso y la calificación de enfermería. Cree en la participación activa de los órganos legislativos de enfermería, administración de salud local y el gobierno federal para la aplicación del proceso de enfermería es factible. .

ABSTRACT Objective: this qualitative study aimed to analyze the perceptions of primary health care management nurses on the nursing process. Method: data were collected through interviews and analyzed by the Content Analysis proposed by Bardin’s theoretical framework. Results: managers recognize the importance of the nursing process, although its implementation was not a priority at the time of the interviews. A conceptual diffi culty and a lack of understanding that the implementation of the care methodology should be a cross-departmental action in the local healthcare management were clearly observed. Conclusion: managers should have their perspectives broadened concerning the relevance of the nursing process and the professional training. The active participation of legislative nursing bodies, local healthcare management and the federal government may open the way for the effective implementation of the nursing process. .

Descomposición de hojarasca en seis arroyos de Bosque Mesófilo de Montaña en la cuenca alta del río La Antigua, Veracruz, México

Leaf litter decomposition in six Cloud Forest streams of the upper La Antigua watershed, Veracruz, Mexico. Leaf litter decomposition is an important stream ecosystem process. To understand factors controlling leaf decomposition in cloud forest in Mexico, we incubated leaf packs in different streams along a land use cover gradient for 35 days during the dry and wet seasons. We assessed relations between leaf decomposition rates (k), stream physicochemistry, and macroinvertebrates colonizing leaf packs. Physicochemical parameters showed a clear seasonal difference at all study streams. Leaves were colonized by collector-gatherer insects, followed by shredders. Assessment of factors related to k indicated that only forest cover was negatively related to leaf decomposition rates. Thus stream physicochemistry and seasonality had no impact on decomposition rates. We concluded that leaf litter decomposition at our study streams is a stable process over the year. However, it is possible that this stability is the result of factors regulating decomposition during the different seasons and streams. Rev. Biol. Trop. 62 (Suppl. 2): 111-127. Epub 2014 April 01.

Para muchos arroyos, la hojarasca proveniente de la zona ribereña es la base de las redes tróficas, por lo cual el proceso de descomposición de la hojarasca es de gran importancia para el funcionamiento de estos ecosistemas. Con el fin de conocer los factores que afectan la descomposición de la hojarasca en arroyos del bosque mesófilo de montaña (BMM), se utilizaron paquetes de hojarasca durante 35 días. Seis arroyos con un gradiente de perturbación fueron estudiados en la época seca y lluviosa. Se determinó la relación entre la tasa de descomposición de la hojarasca (k), con algunos parámetros fisicoquímicos del cuerpo de agua y los macroinvertebrados colonizadores de los paquetes. Los factores fisicoquímicos mostraron una separación de los cuerpos de agua según la época a través de un Análisis de Componentes Principales (ACP). De los insectos colonizadores de los paquetes de hojarasca, el grupo funcional de los recolectores fue el más abundante, seguido por los fragmentadores. Solo se encontró una relación negativa entre la k y el porcentaje de cobertura boscosa (p=0.04) al realizar una regresión múltiple por pasos en la que se incluyeron algunos parámetros fisicoquímicos, el porcentaje de cobertura boscosa y las abundancias promedio de los insectos fragmentadores y no fragmentadores. La descomposición de la hojarasca en los arroyos estudiados parece ser un proceso estable a lo largo del año, aunque los factores responsables por la regulación pueden diferir en las distintas épocas.

Land use effects on leaf litter breakdown in low-order streams draining a rapidly developing tropical watershed in Puerto Rico

Land use has an important role influencing stream ecosystem processes, such as leaf litter breakdown. Here, we assessed rates of leaf litter breakdown in low-order tropical streams draining forest, agriculture, and urban land uses in Puerto Rico. To measure leaf breakdown rates, we placed litter bags made of coarse mesh in nine streams, three for each land use type. At each stream, we measured changes in leaf mass over time, leaf breakdown rates, macroinvertebrate assemblages, and stream physicochemistry. Streams differed in their water physicochemistry, with urban streams showing high values for most variables. Stream physical habitat was evaluated using a visual assessment protocol, which indicated that agricultural and urban streams were more degraded than forested streams. Leaf breakdown rates were fast in all streams (k values ranging 0.006-0.024). Breakdown rates were significantly related to the physical conditions of the stream channel (e.g., visual protocol scores), with fastest rates in forested streams. Invertebrates colonizing leaves were mainly mayflies (Leptophlebiidae, Baetidae, and Caenidae), dipterans (Chironomidae), caddisflies (Polycentropodidae), and beetles (Elmidae and Gyrinidae). Our streams lacked large decapod populations, contrasting with other Puerto Rican streams. We found little evidence for an insect effect on leaf breakdown. Results suggest that land use is an important factor affecting leaf litter processing in streams. In contrast to studies in temperate regions, we found little evidence for a positive nutrient related effect of agricultural land use on decomposition rates. Changes in the physical characteristics of streams appear to be the main drivers behind observed decomposition patterns. Rev. Biol. Trop. 62 (Suppl. 2): 129-142. Epub 2014 April 01.

El uso de la tierra influye significativamente sobre los procesos en ecosistemas de riachuelo, como la descomposición de la hojarasca. En el presente estudio, se evaluaron las tasas de descomposición de la hojarasca en arroyos tropicales menores de zonas boscosa, agrícola y urbana en Puerto Rico. Para medir las tasas de descomposición se colocaron bolsas de malla gruesa en nueve riachuelos, tres para cada uno de los tipos de uso de tierra. Se midieron los cambios en la masa de hojarasca con el tiempo, las tasas de descomposición, la composición de macroinvertebrados y los aspectos fisico-químicos del riachuelo. Los riachuelos mostraron diferencias en la fisico-química del agua: los riachuelos urbanos presentaron los valores más altos en casi todas las variables. Las características físicas del riachuelo fueron evaluadas utilizando un protocolo visual, el cual indica que los riachuelos urbanos y asociados a la agricultura están más degradados que los asociados a bosques. La tasa de descomposición de la hojarasca fue rápida en todos los riachuelos (k=0.006-0.024). La descomposición estuvo relacionada con las condiciones físicas del riachuelo, siendo más rápido en aquellos asociados al bosque. Los invertebrados que colonizaron las hojas fueron principalmente efemerópteros (Leptophlebiidae, Baetidae, and Caenidae), dípteros (Chironomidae), tricópteros (Polycentropodidae) y escarabajos (Elmidae and Gyrinidae). Contrario a lo encontrado en otros estudios, no hallamos decápodos. Hubo poca evidencia de que los insectos afecten la descomposición. Los resultados sugieren que el uso de la tierra es un factor importante que afecta el proceso de descomposición de la hojarasca en los riachuelos. Contrario a los estudios en zonas templadas, hallamos evidencia de una relación positiva de los nutrientes de tierra agrícola con las tasas de descomposición. Los cambios en las características físicas de los riachuelos parecen ser los factores principales en los patrones de descomposición.

Dinámica de nutrientes en plantaciones forestales de Azadirachta indica (Meliaceae) establecidas para restauración de tierras degradadas en Colombia / Nutrient dynamics in forest plantations of Azadirachta indica (Meliaceae) established for resto- ration of degraded lands in Colombia

Azadirachta indica is a tree species which use is steadily increasing for restoration of tropical and subtropical arid and degraded lands throughout the world. The objective of this research study was to evaluate the potential of these plantations as an active restoration model for the recovery of soils under desertification in arid lands of Colombia. Litter traps and litter-bags were installed in twenty 250m² plots. Green leaves and soil samples inside and outside this species plantations were taken, and their elemental concentrations were determined. Litterfall, leaf litter decomposition and foliar nutrient resorption were moni- tored for one year. The annual contributions of organic material, such as fine litterfall, represented 557.54kg/ha, a third of which was A. indica leaves. The greatest potential returns of nutrients per foliar litterfall were from Ca (4.6kg/ha) and N (2.4kg/ha), and the smallest potential returns came from P (0.06kg/ha). A total of 68% of the foliar material deposited in litter-bags disappeared after one year. The greatest release of nutrients was that of K (100%), and the least was that of N (40%). P was the most limiting nutrient, with low edaphic availability and high nutrient use efficiency from Vitousek´s index (IEV=3176) and foliar nutrient resorption (35%). Despite these plantations are young, and that they have not had forestry management practices, as an active restoration model, they have revitalized the biogeochemical cycle, positively modifying the edaphic parameters according to the increases in organic material, P and K of 72%, 31% and 61%, respectively. Furthermore, they improved the stability of aggregates and the microbe respiration rates. The forest plantation model with exotic species has been opposed by different sectors; however, it has been acknowledged that these projects derive many benefits for the restoration of biodiversity and ecosystemic functions. The conditions of severe land degradation demand the initial use of species, such as A. indica, that can adapt quickly and successfully, and progressively reestablish the biogeochemical cycle.

Azadirachta indica A. Juss (Nim) ha sido ampliamente empleada en procedimientos de restauración, por lo tanto se evaluó el potencial de sus plantaciones para restaurar tierras secas degradadas por sobrepastoreo, vía reactivación del ciclo biogeoquímico. En 20 parcelas de 250m², se instalaron trampas de hojarasca y litter-bags. Se tomaron muestras de hojas maduras y de suelos dentro y fuera de las plantaciones, y se determinaron sus contenidos elementales. Fueron monitoreados la caída de hojarasca, la descomposición de hojarasca y la reabsorción de nutrientes foliares durante un año. Los aportes anuales de hojarasca fina representaron 557.54kg/ha (33% hojas de Nim). Los mayores retornos potenciales de nutrientes vía foliar fue- ron de Ca (4.6kg/ha) y N (2.4kg/ha) y los menores de P (0.06kg/ha). El 68% del material se descompuso tras un año. La mayor liberación de nutrientes fue de K (100%) y la menor de N (40%). El P fue el nutriente más limitante, con baja disponibilidad edáfica y alta eficiencia en su uso según el Índice de Vitousek (IEV=3 176) y la reabsorción foliar (35%). Estas plantaciones juveniles demostraron efectividad en la reactivación del ciclo biogeoquímico, que mejoraron parámetros edáficos, según incrementos de materia orgánica, P y K; 72%, 31% y 61%, respectiva- mente. Además mejoraron la estabilidad de agregados y las tasas de respiración microbiana.

Dynamics of leaf litter humidity, depth and quantity: two restoration strategies failed to mimic ground microhabitat conditions of a low montane and premontane forest in Costa Rica

Little is known about how restoration strategies affect aspects like leaf litter’s quantity, depth and humidity. I analyzed leaf litter’s quantity, depth and humidity yearly patterns in a primary tropical lower montane wet forest and two restored areas: a 15 year old secondary forest (unassisted restoration) and a 40 year old Cupressus lusitanica plantation (natural understory). The three habitats are located in the Río Macho Forest Reserve, Costa Rica. Twenty litter samples were taken every three months (April 2009-April 2010) in each habitat; humidity was measured in 439g samples (average), depth and quantity were measured in five points inside 50x50cm plots. None of the restoration strategies reproduced the primary forest leaf litter humidity, depth and quantity yearly patterns. Primary forest leaf litter humidity was higher and more stable (x=73.2), followed by secondary forest (x=63.3) and cypress plantation (x=52.9) (Kruskall-Wallis=77.93, n=232, p=0.00). In the primary (Kruskal-Wallis=31.63, n=78, p<0.001) and secondary (Kruskal-Wallis=11.79, n=75, p=0.008) forest litter accumulation was higher during April due to strong winds. In the primary forest (Kruskal-wallis=21.83, n=78, p<0.001) and the cypress plantation (Kruskal-wallis=39.99, n=80, p<0.001) leaf litter depth was shallow in October because heavy rains compacted it. Depth patterns were different from quantity patterns and described the leaf litter’s structure in different ecosystems though the year.

Poco se sabe acerca de cómo las estrategias de restauración afectan aspectos como la cantidad, profundidad y humedad de la hojarasca. Se analizaron estas variables en un bosque tropical húmedo montano bajo, considerado bosque primario y dos áreas restauradas: un bosque secundario de 15 años (restauración natural) y una plantación de Cupressus lusitanica de 40 años con sotobosque restaurado naturalmente. Los sitios estudiados se ubican en la reserva forestal Río Macho, Costa Rica. Los muestreos se realizaron cada tres meses (abril 2009-abril 2010). En cada ocasión se escogieron al azar 20 cuadrículas de 50x50cm de las que se recogió 439g en promedio de hojarasca para medir la humedad por diferencia entre peso seco y húmedo. En cada cuadrícula se midió la profundidad y cantidad de hojarasca haciendo un promedio de cinco puntos. La cantidad se midió con el número de hojas ensartadas en un picahielos. La profundidad se midió con una regla metálica. Ninguna de las técnicas de restauración reproduce los patrones anuales del bosque primario en cuanto a la humedad, profundidad y cantidad de hojarasca. La humedad de la hojarasca del bosque primario es mas alta y estable ( =73.2), seguida por el bosque secundario ( =63.3) y el cipresal ( =52.9) (Kruskall-Wallis=77.93, n=232, p=0.00). La cantidad de hojarasca acumulada en el bosque primario (Kruskal-Wallis=31.63, n=78, p<0.001) y el secundario (Kruskal-Wallis=11.79, n=75 p=0.008) es mayor en abril debido a los fuertes vientos. La profundidad de la hojarasca del bosque primario (Kruskal-wallis=21.83, n=78, p<0.001) y en el cipresal (Kruskal-wallis=39.99, n=80, p<0.001) es menor durante octubre debido a que los fuertes aguaceros la compactan. Los patrones de cantidad y profundidad de la hojarasca presentan diferencias, que describen la estructura de la hojarasca en diferentes ecosistemas a lo largo del año.

Carbon and nitrogen stock and fluxes in coastal Atlantic Forest of southeast Brazil: potential impacts of climate change on biogeochemical functioning / Estoques e fluxos de carbono e nitrogênio nas zonas costeiras da Mata Atlântica do sudeste do Brasil: potenciais impactos das mudanças climáticas sobre o funcionamento biogeoquímico

The Atlantic Forest is one of the most important biomes of Brazil. Originally covering approximately 1.5 million of km², today this area has been reduced to 12% of its original size. Climate changes may alter the structure and the functioning of this tropical forest. Here we explore how increases in temperature and changes in precipitation distribution could affect dynamics of carbon and nitrogen in coastal Atlantic Forest of the southeast region of Brazil The main conclusion of this article is that the coastal Atlantic Forest has high stocks of carbon and nitrogen above ground, and especially, below ground. An increase in temperature may transform these forests from important carbon sinks to carbon sources by increasing loss of carbon and nitrogen to the atmosphere. However, this conclusion should be viewed with caution because it is based on limited information. Therefore, more studies are urgently needed to enable us to make more accurate predictions.

A Mata Atlântica é um dos mais importantes biomas do Brasil. Sua cobertura original estendia-se por aproximadamente 1,5 milhão de km². Atualmente, sua área ocupa somente 12% de sua cobertura original. As mudanças climáticas podem alterar a estrutura e o funcionamento dessa floresta tropical. Neste artigo, discute-se como aumentos na temperatura do ar e mudanças na distribuição das chuvas podem afetar a dinâmica do carbono e do nitrogênio na Mata Atlântica litorânea da Região Sudeste brasileira, cuja disponibilidade de informações é maior. A principal conclusão deste artigo é que essas florestas detêm elevados estoques de carbono e nitrogênio acima do solo e, especialmente, abaixo do solo. Um aumento na temperatura do ar pode transformar essas florestas de sumidouros para fontes de carbono para a atmosfera por meio de um aumento nos processos de decomposição. Entretanto, essas conclusões devem ser vistas com cautela já que estão baseadas em um número limitado de informações. Portanto, é urgente que um número maior de informações seja produzido, permitindo conclusões mais robustas no futuro.

Biogeochemical cycling in terrestrial ecosystems of the Caatinga Biome / Ciclagem biogeoquímica em ecossistemas terrestres do Bioma Caatinga

The biogeochemical cycles of C, N, P and water, the impacts of land use in the stocks and flows of these elements and how they can affect the structure and functioning of Caatinga were reviewed. About half of this biome is still covered by native secondary vegetation. Soils are deficient in nutrients, especially N and P. Average concentrations of total soil P and C in the top layer (0-20 cm) are 196 mg kg-1 and 9.3 g kg-1, corresponding to C stocks around 23 Mg ha-1. Aboveground biomass of native vegetation varies from 30 to 50 Mg ha-1, and average root biomass from 3 to 12 Mg ha-1. Average annual productivities and biomass accumulation in different land use systems vary from 1 to 7 Mg ha-1 year-1. Biological atmospheric N2 fixation is estimated to vary from 3 to 11 kg N ha-1 year-1and 21 to 26 kg N ha-1 year-1 in mature and secondary Caatinga, respectively. The main processes responsible for nutrient and water losses are fire, soil erosion, runoff and harvest of crops and animal products. Projected climate changes in the future point to higher temperatures and rainfall decreases. In face of the high intrinsic variability, actions to increase sustainability should improve resilience and stability of the ecosystems. Land use systems based on perennial species, as opposed to annual species, may be more stable and resilient, thus more adequate to face future potential increases in climate variability. Long-term studies to investigate the potential of the native biodiversity or adapted exotic species to design sustainable land use systems should be encouraged.

Os ciclos biogeoquímicos de C, N, P e água, os impactos das mudanças do uso da terra nos estoques e fluxos destes elementos e como estas mudanças podem afetar a estrutura e o funcionamento da Caatinga foram revisados. Cerca da metade desse Bioma ainda é coberta por vegetação nativa secundária. Os solos são deficientes em nutrientes, principalmente N e P. A concentração média, na camada superficial (0-20 cm), de P total é 196 mg kg-1, e a de C é 9.3 g kg-1, correspondendo a estoques médios em torno de 23 Mg ha-1 de carbono. A biomassa aérea da vegetação varia entre 30 a 50 Mg ha-1, e a biomassa radicular entre 3 a 12 Mg ha-1. As produtividades e acumulações anuais de biomassa nos diferentes usos da terra variam de 1 a 7 Mg ha-1. A fixação biológica de N2 atmosférico é estimada em 3 a 11 kg N ha-1 ano-1 e 21 a 26 kg N ha-1 ano-1 em Caatinga madura e em regeneração, respectivamente. Os principais processos de perda de nutrientes e água são queimadas, erosão do solo, escoamento e colheita de cultivos e produtos animais. As mudanças climáticas projetadas indicam maiores temperaturas e menores precipitações. Considerando a alta variabilidade intrínseca, ações para aumentar a sustentabilidade deveriam melhorar a resiliência e a estabilidade dos ecossistemas. Sistemas de uso da terra baseados em espécies perenes, em contraposição a anuais, devem ser mais estáveis e resilientes, portanto mais adequados para enfrentar os potenciais aumentos na variabilidade climática. Estudos de longa duração para avaliar o potencial da biodiversidade nativa ou de exóticas adaptadas no delineamento de sistemas de uso sustentáveis deveriam ser encorajados.

Potential impacts of climate change on biogeochemical functioning of Cerrado ecosystems / Os impactos potenciais das mudanças climáticas no funcionamento biogeoquímico dos ecossistemas de cerrado

The Cerrado Domain comprises one of the most diverse savannas in the world and is undergoing a rapid loss of habitats due to changes in fire regimes and intense conversion of native areas to agriculture. We reviewed data on the biogeochemical functioning of Cerrado ecosystems and evaluated the potential impacts of regional climate changes. Variation in temperature extremes and in total amount of rainfall and altitude throughout the Cerrado determines marked differences in the composition of species. Cerrado ecosystems are controlled by interactions between water and nutrient availability. In general, nutrient cycles (N, P and base cations) are very conservative, while litter, microbial and plant biomass are important stocks. In terms of C cycling, root systems and especially the soil organic matter are the most important stocks. Typical cerrado ecosystems function as C sinks on an annual basis, although they work as source of C to the atmosphere close to the end of the dry season. Fire is an important factor altering stocks and fluxes of C and nutrients. Predicted changes in temperature, amount and distribution of precipitation vary according to Cerrado sub-regions with more marked changes in the northeastern part of the domain. Higher temperatures, decreases in rainfall with increase in length of the dry season could shift net ecosystem exchanges from C sink to source of C and might intensify burning, reducing nutrient stocks. Interactions between the heterogeneity in the composition and abundance of biological communities throughout the Cerrado Domain and current and future changes in land use make it difficult to project the impacts of future climate scenarios at different temporal and spatial scales and new modeling approaches are needed.

O Domínio Cerrado é composto por uma das savanas mais diversas do mundo e está passando por uma rápida perda de habitats devido às mudanças nos regimes de fogo e intensa conversão de áreas nativas para a agricultura. Os dados sobre o funcionamento biogeoquímico do Cerrado foram revisados, avaliando-se os potenciais impactos das mudanças climáticas regionais. As variações na temperatura, na precipitação e altitude ao longo do Cerrado determinam diferenças marcantes na composição das espécies. Os ecossistemas de Cerrado são controlados por interações entre a água e a disponibilidade de nutrientes. Em geral, a ciclagem de nutrientes (N, P e cátions) são muito conservadores, enquanto a serapilheira, a biomassa microbiana e vegetal são importantes compartimentos de estoque. Em termos de ciclagem de C, o sistema radicular e, especialmente, a matéria orgânica do solo são os estoques mais importantes. Em bases anuais, o ecossistema de cerrado típico funciona como sumidouros de C embora o opere como fonte de C para a atmosfera ao final da estação seca. O fogo é um fator importante alterando os estoques e fluxos de C e nutrientes. As previsões de mudanças na temperatura, quantidade e distribuição da precipitação variam de acordo com as sub-regiões do Cerrado, com mudanças mais acentuadas na parte nordeste do domínio. As temperaturas mais elevadas, diminuição da precipitação com o aumento da duração da estação seca, podem deslocar as trocas líquida do ecossistema de dreno para a fonte de C e podem intensificar as queimadas, reduzindo os estoques de nutrientes. As interações entre a heterogeneidade na composição e abundância das comunidades biológicas ao longo do Domínio Cerrado com as mudanças atuais e futuras do uso da terra tornam difícil a projeção dos impactos dos cenários climáticos futuros em diferentes escalas temporais e espaciais e novas abordagens de modelagem são necessárias.

Functional diversity, soil features and community functioning: a test in a cerrado site / Diversidade funcional, características edáficas e funcionamento de comunidade: teste em um sítio de cerrado

Community functioning may be affected by functional diversity, which measures the extent of complementarity in resource use. We tested whether there was a relationship between functional diversity of woody species and community functioning on a fine scale, using FD as a measure of functional diversity and litter decomposition rate as a surrogate for community functioning. We measured eight functional traits from a woodland cerrado community in southeastern Brazil. Then, we tested the correlation between FD and the decomposition rate taking into account differences in soil features and between decomposition rate and each trait separately. The decomposition rate was related to the aluminium and phosphorus concentration in soil, but not to FD, pointing out that functional diversity was not a good predictor of community functioning. There was a non-significant relationship between FD and the decomposition rate even when we considered each trait separately. Most studies in the relationships between biodiversity and community functioning on fine scales were carried out by experimental manipulation of diversity and in temperate regions. We carried out this fine scale study as a mensurative experiment and in a tropical savanna. Our findings indicated that the relationship between biodiversity and community functioning is not as straightforward as usually assumed.

O funcionamento das comunidades deve ser afetado pela diversidade funcional, uma vez que esta mede a extensão da complementaridade no uso de recursos. Testamos se havia relação entre diversidade funcional das espécies arbóreas e o funcionamento da comunidade em escala fina, usando a FD como medida de diversidade funcional e a taxa de decomposição da serapilheira como indicadora do funcionamento. Medimos oito traços funcionais de plantas arbóreas em uma comunidade de cerrado no sudeste do Brasil. Testamos a correlação entre a FD e as taxas de decomposição, considerando diferenças nas variáveis edáficas e entre as taxas de decomposição e cada traço, separadamente. As taxas de decomposição se mostraram relacionadas com as concentrações de alumínio e fósforo, e não com a FD, indicando que a diversidade funcional não é uma boa preditora do funcionamento da comunidade. Não houve relação significativa entre FD e decomposição, mesmo quando consideramos cada traço separadamente. A maioria dos estudos sobre a relação entre diversidade e funcionamento em escalas finas foi desenvolvida por meio da manipulação experimental da diversidade e em regiões temperadas. Nossos resultados indicaram que a relação entre biodiversidade e funcionamento das comunidades não é tão direta como se assume usualmente.

Modeling radiative transfer in tropical rainforest canopies: sensitivity of simulated albedo to canopy architectural and optical parameters

This study evaluates the sensitivity of the surface albedo simulated by the Integrated Biosphere Simulator (IBIS) to a set of Amazonian tropical rainforest canopy architectural and optical parameters. The parameters tested in this study are the orientation and reflectance of the leaves of upper and lower canopies in the visible (VIS) and near-infrared (NIR) spectral bands. The results are evaluated against albedo measurements taken above the K34 site at the INPA (Instituto Nacional de Pesquisas da Amazônia) Cuieiras Biological Reserve. The sensitivity analysis indicates a strong response to the upper canopy leaves orientation (x up) and to the reflectivity in the near-infrared spectral band (rNIR,up), a smaller sensitivity to the reflectivity in the visible spectral band (rVIS,up) and no sensitivity at all to the lower canopy parameters, which is consistent with the canopy structure. The combination of parameters that minimized the Root Mean Square Error and mean relative error are Xup = 0.86, rVIS,up = 0.062 and rNIR,up = 0.275. The parameterizations performed resulted in successful simulations of tropical rainforest albedo by IBIS, indicating its potential to simulate the canopy radiative transfer for narrow spectral bands and permitting close comparison with remote sensing products.

Este estudo avalia a sensibilidade do albedo da superfície pelo Simulador Integrado da Biosfera (IBIS) a um conjunto de parâmetros que representam algumas propriedades arquitetônicas e óticas do dossel da floresta tropical Amazônica. Os parâmetros testados neste estudo são a orientação e refletância das folhas do dossel superior e inferior nas bandas espectrais do visível (VIS) e infravermelho próximo (NIR). Os resultados são avaliados contra observações feitas no sítio K34 pertencente ao Instituto Nacional de Pesquisas da Amazônia (INPA) na Reserva Biológica de Cuieiras. A análise de sensibilidade indica uma forte resposta aos parâmetros de orientação das folhas do dossel superior (x up ) e à refletância na banda do infravermelho próximo (pNIR,up), uma menor sensibilidade à refletância na banda espectral do visível (pVISup) e nenhuma sensibilidade aos parâmetros da parte inferior do dossel, o que é consistente com a estrutura do dossel. A combinação de parâmetros que minimizaram a raiz do erro quadrado médio e o erro relativo médio são Xup= 0, 86, pVISup = 0, 062 e pNIR,up = 0, 275. As parametrizações realizadas resultaram em simulações bem sucedidas do albedo de floresta tropical pelo IBIS, indicando seu potencial para simular a transferência radiativa do dossel para bandas espectrais estreitas, permitindo a comparação com produtos de sensoriamento remoto.

Nutrient fluxes in litterfall of a secondary successional alluvial rain forest in Southern Brazil

During forest succession, litterfall nutrient fluxes increase significantly. The higher inputs of organic matter and nutrients through litterfall affects positively soil fertility and the species composition, which are essential components in forest restoration and management programs. In the present study, the input of nutrients to the forest soil via litterfall components was estimated for two sites of different development stages, in an early successional alluvial rain forest in Brazil. Litterfall returned to the soil, in kg/ha, ca. 93 N, 79 Ca, 24 K, 15 Mg, 6 P, 1.7 Mn, 0.94 Fe, 0.18 Zn, 0.09 Cu and 11.2 Al, in the site where trees were more abundant and had higher values of basal area. In the other area, where trees where less abundant and values of basal area were comparatively low, litterfall returned <50% of those amounts to the forest soil, except for Al. The amount of Al that returned to the soil was similar in both areas due to the high contribution of Tibouchina pulchra (82% of Al returned). Comparatively, high proportion of three dominant native tree species (Myrsine coriacea, T. pulchra and Cecropia pachystachya) explained better litter nutrient use efficiency (mainly N and P) in the site with the least advanced successional stage. Although litterfall of these species show lower nutrient concentrations than the other tree species, their nutrient fluxes were high in both sites, indicating a certain independence from soil essential nutrients. Such feature of the native species is very advantageous and should be considered in forest restoration programs. Rev. Biol. Trop. 59 (4): 1869-1882. Epub 2011 December 01.

Durante la sucesión secundaria forestal, el flujo de nutrientes en la hojarasca se incrementa significativamente. Los altos ingresos de materia orgánica y nutrientes a través de la hojarasca afecta positivamente la fertilidad del suelo y la composición de especies, las cuales son componentes esenciales para programas de restauración forestal y de manejo. En el presente estudio, el ingreso de nutrientes a través de la hojarasca y sus componentes fueron estimados para dos sitios de una selva lluviosa atlántica aluvial en sucesión temprana. La cantidad anual de elementos que ingresan al suelo desde la vegetación más desarrollada (sitios con alta área basal y abundancia de árboles) fueron (en kg/ha): 93 N, 79 Ca, 24 K, 15 Mg, 6 P, 1.7 Mn, 0.94 Fe, 0.18 Zn, 0.09 Cu y 11.2 Al. Menos de la mitad de esas cantidades fueron aportadas por la vegetación menos desarrollada, excepto para el Al. La cantidad de Al aportada a este sitio fue similar a la contribución de la vegetación más desarrollada, debido a la contribución de: Tibouchina pulchra (82% de todo el Al aportado). La eficiencia en el uso de nutrientes de la hojarasca (principalmente de N y P) de la vegetación menos desarrollada fue superior a la eficiencia de una más desarrollada, debido a la alta proporción de tres especies nativas dominantes (Myrsine coriacea, Tibouchina pulchra y Cecropia pachystachya) en la primera. Si bien la hojarasca de esas especies presenta menor concentración de nutrientes que las otras especies arbóreas, el flujo de nutrientes fue mayor (para ambos sitios), marcando una cierta independencia de los nutrientes esenciales del suelo. Las cantidades de esas especies deberían ser consideradas con mayor atención para su uso en programas de restauración forestal.

Ciclos biogeoquímicos en bosques naturales y plantaciones de coníferas en ecosistemas de alta montaña de Colombia

Biogeochemical cycles in natural forest and conifer plantations in the high mountains of Colombia. Plant litter production and decomposition are two important processes in forest ecosystems, since they provide the main organic matter input to soil and regulate nutrient cycling. With the aim to study these processes, litterfall, standing litter and nutrient return were studied for three years in an oak forest (Quercus humboldtii), pine (Pinus patula) and cypress (Cupressus lusitanica) plantations, located in highlands of the Central Cordillera of Colombia. Evaluation methods included: fine litter collection at fortnightly intervals using litter traps; the litter layer samples at the end of each sampling year and chemical analyses of both litterfall and standing litter. Fine litter fall observed was similar in oak forest (7.5Mg ha/y) and in pine (7.8Mg ha/y), but very low in cypress (3.5Mg ha/y). Litter standing was 1.76, 1.73 and 1.3Mg ha/y in oak, pine and cypress, respectively. The mean residence time of the standing litter was of 3.3 years for cypress, 2.1 years for pine and 1.8 years for oak forests. In contrast, the total amount of retained elements (N, P, S, Ca, Mg, K, Cu, Fe, Mn and Zn) in the standing litter was higher in pine (115kg/ha), followed by oak (78kg/ha) and cypress (24kg/ha). Oak forests showed the lowest mean residence time of nutrients and the highest nutrients return to the soil as a consequence of a faster decomposition. Thus, a higher nutrient supply to soils from oaks than from tree plantations, seems to be an ecological advantage for recovering and maintaining the main ecosystem functioning features, which needs to be taken into account in restoration programs in this highly degraded Andean mountains. Rev. Biol. Trop. 59 (4): 1883-1894. Epub 2011 December 01.

La caída y descomposición de hojarasca representan los principales ingresos de materia orgánica y nutrientes a los ecosistemas forestales. Se estudiaron la caída y acumulación de hojarasca fina y el retorno de nutrientes, en un robledal (Quercus humboldtii) y en plantaciones de pino (Pinus patula) y ciprés (Cupressus lusitanica) en tierras altas de Colombia. La caída de hojarasca fina fue similar entre el robledal (7.5Mg/ha.a) y el pinar (7.8Mg/ha.a), y muy inferior en el cipresal (3.5Mg/ha.a). El mantillo representó 1.76, 1.73 y 1.3Mg/ha.a en el robledal, pinar y cipresal, respectivamente. El tiempo medio de residencia (TMR) del mantillo siguió la secuencia: cipresal (3.3 años)>pinar (2.1 años)>robledal (1.8 años). La cantidad de nutrientes retenidos en el mantillo siguió la secuencia: pinar (115kg/ ha)>robledal (78kg/ha)>cipresal (24kg/ha). Los menores TMR de nutrientes se presentaron para la hojarasca foliar del robledal, en su mayoría inferiores a 1.0 años. En términos de la función ecosistémica en el robledal los procesos estudiados son muy superiores vía provisión de nutrientes al suelo y regulación de los ciclos biogeoquímicos, aspectos que deben ser considerados previa implementación de programas de repoblamiento forestal.

Restauración ecológica de bosques tropicales en Costa Rica: efecto de varios modelos en la producción, acumulación y descomposición de hojarasca

Tropical forest restoration in Costa Rica: the effect of several strategies on litter production, accumulation and decomposition. Tropical forest restoration strategies have the potential to accelerate the recovery of the nutrient cycles in degraded lands. Litter production and its decomposition represent the main transfer of organic material and nutrients into the soil substrate. We evaluated litter production, accumulation on the forest floor, and its decomposition under three restoration strategies: plantation (entire area planted with trees), island (trees planted in patches of three different sizes) and control (natural regeneration) plots. We also compared restoration strategies to young secondary forest (7-9yr). Restoration treatments were established in 50x50m plots in June 2004 at six sites in Southern Costa Rica. Planted tree species included two native timber species (Terminalia amazonia and Vochysia guatemalensis) interplanted with two N fixers (Erythrina poeppigiana and Inga edulis). Litter was collected every 15 days between September 2008 and August 2009 in 12 0.25m² litter traps distributed within each plot; litter that accumulated on the soil surface was collected at four locations (0.25m² quadrats) within each plot in February and May 2009. Total litter production in plantation (6.3Mg/ha) and secondary forest (7.3Mg/ha) did not differ, but were greater than in islands (3.5Mg/ha) and control (1.4Mg/ha). Plantation had greatest accumulation of litter on the soil surface (10.6Mg/ha) as compared to the other treatments (SF=7.2; I=6.7; C=4.9). Secondary forest was the only treatment with a greater annual production of litter than litter accumulation on the soil surface. Carbon storage in litter was similar between plantation and secondary forest, and significantly greater than the other treatments. No differences were found for carbon concentration and storage in the soil among treatments. There was also high variability in the production and accumulation of litter and carbon among sites. Active restoration treatments accelerated the production of litter and carbon storage in comparison to areas under natural recovery. However, the nutrient cycle has not necessarily been restored under these conditions, as high litter accumulation on the soil surface indicates a low decomposition rate, which slows nutrient return to the soil. Rev. Biol. Trop. 59 (3): 1323-1336. Epub 2011 September 01.

Estrategias de restauración tienen el potencial de acelerar el restablecimiento del ciclo de nutrientes en áreas degradadas. En este estudio, se evaluó la producción de hojarasca, su acumulación y descomposición bajo tres tratamientos: plantación (toda la superficie plantada); islas (árboles sembrados en parches de tres tamaños) y testigo (regeneración natural). También se compararon bosques secundarios jóvenes (7-9 años). Los tratamientos fueron establecidos en parcelas de 50x50m en junio 2004 en seis sitios en el sur de Costa Rica. Las especies introducidas fueron dos maderables (Terminalia amazonia y Vochysia guatemalensis) intercaladas con dos fijadoras de nitrógeno (Erythrina poeppigiana e Inga edulis). La producción total de hojarasca en la plantación y bosque secundario no difirió significativamente, fue mayor que en las islas y el testigo. La plantación presentó mayor acumulación de hojarasca sobre el suelo. Los resultados indican una gran variabilidad entre los sitios. Ambas estrategias de restauración activas aceleraron la producción y acumulación de hojarasca en comparación con la regeneración. No obstante, eso no implica la restauración del ciclo de nutrientes. La elevada acumulación de hojarasca sobre el suelo indica baja tasa de descomposición y de retorno de nutrientes al suelo.

Soil dehydrogenase in a land degradation-rehabilitation gradient: observations from a savanna site with a wet/dry seasonal cycle

Soil dehydrogenase activity is a good indicator of overall microbial activity in soil, and it can serve as a good indicator of soil condition. However, seasonal changes in soil moisture content may have an effect on soil dehydrogenase activity, making an accurate assessment of soil condition difficult. In this study, we attempted to determine the significance of soil dehydrogenase activity for assessing soil condition, and we attempted to find a way to account for the influence of soil moisture content on soil dehydrogenase activity. Soils were sampled in dry evergreen forest (original vegetation), bare ground (severely degraded) and Acacia plantation plots established on bare ground in 1986 and 1987 in Sakaerat, Thailand. Soil physico-chemical characteristics and dehydrogenase activity in the Acacia plantation soil had few differences from those in the evergreen forest soil. Soil dehydrogenase activity varied significantly between the bare ground and the forests regardless of the season (wet or dry), while the season did not produce a significant variation in soil dehydrogenase activity, as determined by repeated measures analysis of variance (p=0.077). The physico-chemical data provided the first principal component as a good measure of soil fertility. Values of soil dehydrogenase activity significantly correlated to scores of the soil samples of the first principal component (R=0.787, p<0.001). We found that soil dehydrogenase activity is a useful indicator of the extent of soil degradation and the rehabilitative effects of reforestation in this part of Thailand. Rev. Biol. Trop. 57 (1-2): 223-234. Epub 2009 June 30.

Diurnal and seasonal carbon balance of four tropical tree species differing in successional status / Balanço de carbono diurno e sazonal de quatro espécies tropicais arbóreas de diferentes grupos sucessionais

This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical tree species under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical tree species, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer species, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional species, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional species were similar to pioneer species. On the other hand, photorespiration rates were often higher in pioneer than in late successional species in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all species in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of species. In both evaluated months, there were no differences among species of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional species in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality.

Este estudo considerou algumas questões sobre como um adequado balanço de carbono foliar pode ser obtido por diferentes grupos funcionais de espécies tropicais arbóreas sob contrastantes ambientes luminosos em uma floresta. O estudo foi realizado em um fragmento de floresta estacional semidecidual localizada no município de Narandiba, Estado de São Paulo. Plântulas com dez meses de idade de quatro espécies, Bauhinia forficata Link (Caesalpinioideae) e Guazuma ulmifolia Lam. (Sterculiaceae) como espécies pioneiras, e Hymenaea courbaril L. (Caesalpinioideae) e Esenbeckia leiocarpa Engl. (Rutaceae) como espécies secundárias, cresceram em um ambiente de clareira e um de sub-bosque durante nove meses. Cursos diários da fotossíntese líquida (Pn) e transpiração foram medidos com um medidor portátil de trocas gasosas por infravermelho nas estações seca e chuvosa. A respiração no escuro (Rd) e a fotorrespiração (Pr) foram também avaliadas nas mesmas folhas utilizadas para as medidas de Pn após um período de adaptação ao escuro. Nossos resultados mostraram que a respiração integrada ao longo do dia foi similar entre as espécies dos dois grupos sucessionais. Por outro lado, a fotorrespiração das espécies pioneiras foi freqüentemente maior do que nas espécies secundárias em condições de clareira. Todavia, a contribuição relativa de Pr no balanço de carbono nas folhas foi similar em todas as espécies em ambos os ambientes. Independentemente da espécie, a fotossíntese bruta, considerando os valores integrados ao longo do dia, foi significativamente maior na clareira que no sub-bosque. Nas duas épocas avaliadas, não foram observadas diferenças significativas em nenhum dos parâmetros avaliados entre as espécies crescidas no ambiente de sub-bosque. O mesmo foi observado no mês de maio sob condições de clareira. No mês de novembro, as espécies pioneiras apresentaram uma performance ecofisiológica significativamente distinta das espécies secundárias no ...

Adsorption studies on teak leaves (Tectona grandis): removal of lead ions from wastewater.

Teak leaves (Tectona grandis) abundantly available in India showed high sorption capacity for lead ions and were found efficient for the removal of lead ions from aqueous solutions. The extent of removal was found to be dependent on pH, temperature, concentration of metal ions and the dose of adsorbent. Thermodynamic parameters were calculated at different temperatures. The sorbent once used can be regenerated and recycled two - three times almost with the same capacity. However, regeneration by column operation gave better results than batch process.

Nitrogen and phosphorus resorption in a neotropical rain forest of a nutrient-rich soil

In tropical forests with nutrient-rich soil tree’s nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nutrient resorption in a nutrient-rich soil. The soil concentrations of total N and extractable P, among other physical and chemical characteristics, were analysed in 30 samples in the soil surface (10 cm) of three undisturbed forest plots at ‘Estación de Biología Los Tuxtlas’ on the east coast of Mexico (18°34’ - 18°36’ N, 95°04’ - 95°09’ W). N and P resorption proficiency were determined from senescing leaves in 11 dominant tree species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid. Soil was rich in total N (0.50%, n = 30) and extractable P (4.11 µg g-1, n = 30). As expected, trees showed incomplete N (1.13%, n = 11) and P (0.11%, n = 11) resorption. With a more accurate method of nutrient resorption assessment, it is possible to prove that a forest community with a nutrient-rich soil can have low levels of N and P resorption

En las selvas tropicales con suelos fértiles se ha observado que la reabsorción de nutrientes de los arboles de las hojas seniles no siempre es baja. Esta falta de consistencia en el resultado es talvez debida en parte a la metodología de reabsorción de nutrientes utilizada. El objetivo de este estudio fue analizar la reabsorción final de N y P de arboles de la selva húmeda tropical en un suelo rico en nutrientes. La hipótesis planteada fue que en un suelo rico en nutrientes los arboles presentarían una baja reabsorción final de nutrientes. En 30 muestras del suelo superficial (10 cm) de tres sitios de la selva no perturbada, se analizó entre otras características físicas y químicas, la concentración de N total y P extraíble. A través de la concentración de N y P en hojas seniles, se determinó la reabsorción real de 11 especies dominantes de arboles de esta selva. El N se analizó por digestión microkjeldahl con ácido sulfúrico y destilación con ácido bórico, y el P se analizó por digestión con ácido nítrico y destilación con perclórico. El suelo fue rico en N total (0.50%, n = 30) y P extraíble (4.11 µg g-1, n = 30). Tal como se esperaba, los arboles mostraron una reabsorción incompleta para el N (1.13%, n = 11) y P (0.11%, n = 11)

Plant regeneration from single-nodal-stem explants of legume tree Prosopis alba Griseb

Seeds of Prosopis alba were scarified with abrasive paper and placed to germinate on MS (Murashige and Skoog 1962) nutrient medium. After 7 days of culture, the basal part of cotyledons was removed and pieces of 4 mm" from distal parts were cultured on Murashige and Skoog (1962) mineral salts and vitamins (MS) (3 sucrose) supplemented with growth regulators. Callus proliferation took place in the majority of the media tested. A low percentage of calluses with green buds that developed on MS basal medium containing 0.1 mg.L-1 2,4-D alone or supplemented with BAP at 0.1 mg.L-1 was observed. Neither cotyledonary segments in any medium assayed regenerated the whole plants. Bud elongation (near 70) was achieved when single-nodal-stem segments cut from 20 days old seedlings were cultured on MS salts supplemented with 3 mg.L-1 NAA or 3 mg.L-1 IBA combined with 0.05 mg.L-1 KIN after 60 days in culture. Multiple shoots per bud were also observed. Single-nodal-stem segments from five-year-old plants were also cultured on the same media used for seedling explants. Maximal frequency of explants with bud elongation (near 70) was found on MS with 0.1 mg.L-1 NAA plus 1 mg.L-1 BAP after 60 days of culture. Single-nodal-stem explants cut from adult trees (more than 20 years) were also employed, but the number of bud elongation was lesser. For rooting, the elongated shoots were transferred to a semisolid or liquid MS culture medium employing a paper bridge, supplemented with 0.5 mg.L-1 IBA or 0.1 mg.L-1 NAA.