Scale-dependent relationships between tree species richness and ecosystem function in forests

1. The relationship between species richness and ecosystem function, as measured by productivity or biomass, is of long-standing theoretical and practical interest in ecology. This is especially true for forests, which represent a majority of global biomass, productivity and biodiversity. 2. Here, we conduct an analysis of relationships between tree species richness, biomass and productivity in 25 forest plots of area 8-50ha from across the world. The data were collected using standardized protocols, obviating the need to correct for methodological differences that plague many studies on this topic. 3. We found that at very small spatial grains (0.04ha) species richness was generally positively related to productivity and biomass within plots, with a doubling of species richness corresponding to an average 48% increase in productivity and 53% increase in biomass. At larger spatial grains (0.25ha, 1ha), results were mixed, with negative relationships becoming more common. The results were qualitatively similar but much weaker when we controlled for stem density: at the 0.04ha spatial grain, a doubling of species richness corresponded to a 5% increase in productivity and 7% increase in biomass. Productivity and biomass were themselves almost always positively related at all spatial grains. 4. Synthesis. This is the first cross-site study of the effect of tree species richness on forest biomass and productivity that systematically varies spatial grain within a controlled methodology. The scale-dependent results are consistent with theoretical models in which sampling effects and niche complementarity dominate at small scales, while environmental gradients drive patterns at large scales. Our study shows that the relationship of tree species richness with biomass and productivity changes qualitatively when moving from scales typical of forest surveys (0.04ha) to slightly larger scales (0.25 and 1ha). This needs to be recognized in forest conservation policy and management.

CTFS-ForestGEO: a worldwide network monitoring forests in an era of global change

Global change is impacting forests worldwide, threatening biodiversity and ecosystem services including climate regulation. Understanding how forests respond is critical to forest conservation and climate protection. This review describes an international network of 59 long-term forest dynamics research sites (CTFS-ForestGEO) useful for characterizing forest responses to global change. Within very large plots (median size 25ha), all stems 1cm diameter are identified to species, mapped, and regularly recensused according to standardized protocols. CTFS-ForestGEO spans 25 degrees S-61 degrees N latitude, is generally representative of the range of bioclimatic, edaphic, and topographic conditions experienced by forests worldwide, and is the only forest monitoring network that applies a standardized protocol to each of the world's major forest biomes. Supplementary standardized measurements at subsets of the sites provide additional information on plants, animals, and ecosystem and environmental variables. CTFS-ForestGEO sites are experiencing multifaceted anthropogenic global change pressures including warming (average 0.61 degrees C), changes in precipitation (up to +/- 30% change), atmospheric deposition of nitrogen and sulfur compounds (up to 3.8g Nm(-2)yr(-1) and 3.1g Sm(-2)yr(-1)), and forest fragmentation in the surrounding landscape (up to 88% reduced tree cover within 5km). The broad suite of measurements made at CTFS-ForestGEO sites makes it possible to investigate the complex ways in which global change is impacting forest dynamics. Ongoing research across the CTFS-ForestGEO network is yielding insights into how and why the forests are changing, and continued monitoring will provide vital contributions to understanding worldwide forest diversity and dynamics in an era of global change.

En las raíces ideológicas de Montoneros : John William Cooke lee a Gramsci en Cuba

Desde 1945 la izquierda argentina no pudo resolver el enigma planteado por el hecho de que la clase obrera era peronista. Varios intentos teóricos fracasaron antes de que John William Cooke hiciera el suyo a mediados de los años sesenta. Influenciado por Gramsci, consideró que la clase obrera es una categoría histórica, por lo que el peronismo era la experiencia histórica de la clase obrera argentina y, como tal, revolucionario. Neutralizó el papel político de Perón convirtiéndolo en el símbolo de la identidad peronista. Por esto, la teoría de Cooke fue clave para que guerrilleros de izquierda se declararan peronistas sin que les importaran las opiniones e intenciones políticas de Perón. Las limitaciones de esa teoría quedaron expuestas cuando el general regresó a la Argentina y fue electo presidente por tercera vez.

Aquecimento global : George Leuzinger e um alerta fotográfico

Descreve, tomando por base uma fotografia de 1865, algumas iniciativas para preservação da natureza realizadas no Brasil durante o século XIX. Resume dados biográficos do suíço George Leuzinger, dando ênfase a preocupação ecológica desse fotógrafo. Afirma a necessidade de transformar o ser humano em "parasita do Bem", extraindo do planeta Terra o seu sustento, mas retribuindo com a correção dos malefícios feitos até agora.

California Cooperative Fisheries Investigations. Hydrographic data report, Monterey Bay, January to December 1975

PDF contains 160 pages)

Vertical transport and exchange of materials in the upper waters of the oceans (VERTEX): introduction to the program, hydrographic conditions and major component fluxes during VERTEX I

This paper introduces VERTEX, a multi-disciplinary research program dealing with various aspects of particle transport in the upper, high-energy layers (0-2000 m) of the ocean. Background information is presented on hydrography, biological composition of trapped particulates, and major component fluxes observed on a cruise off central California (VERTEX I). Organic C fluxes measured with two trap systems are compared with several other estimates taken from the literature. The intent of this overview paper is to provide a common setting in an economical manner, and avoid undue repetition of background and ancillary information in subsequent publications. (PDF is 43 pages).

Collecção das Leis do Brazil de 1812

Parte 1 - Cartas de Lei, Alvarás, Decretos e Cartas Régias

Collecção das Leis do Imperio do Brazil de 1882

Parte 1 - Atos do Poder Legislativo

Redeeming America's Fall from Grace between Utopian and Dystopian horizons: The case of George Lucas's Star Wars trilogy

Eterio Pajares, Raquel Merino y José Miguel Santamaría (eds.)

California Cooperative Fisheries Investigations. Hydrographic data report. Monterey Bay. July to December, 1974

In July 1974 Moss Landing Marine Laboratories began the continuation of the bi-weekly hydrographic observations in Monterey Bay. From 1951 to this date, these stations were sampled by personnel at Hopkins Marine Station in Pacific Grove. Small changes were made in the sampling routine: 1) to facilitate squid (Loligo opa1escens) studies, our observations were made at night, and 2) stations 1125 and 1154 are sampled in addition to five stations originally used by Hopkins Marine Station (2201, 2202, 2203, 2204, and 2205). These additional stations will provide important data of the nearshore environment. PDF contains 86 pages)

Relatorio e synopse dos trabalhos da Camara dos Srs. Deputados : nas sessões do anno de 1882 : acompanhada de differentes documentos, quadros estatisticos e informações : organizados na Secretaria da Camara dos Deputados

Sinopse dos trabalhos da Câmara dos Deputados, em 1882.

The age and growth of the tongue sole Cynoglossus canariensis (Steind 1882)

The geometric mean regression equation for the weight; length relationship of Cynoglossus canariensis was W = 0.0025 L super(3.1770). The Von Bertalanffy constants Woo, Loo, K, and to were 507.5852 g, 47.3683 cm, 0.3333 and 0.1397 for males and 839.0753 g, 54.4720 cm, 0.3062 and 0.1737 for females. Total mortality coefficient Z ranged from 0.6482 and 0.8021

The genesis and achievement of a limnologist: George Evelyn Hutchinson, 1903-1991

An obituary of the limnologist G.E. Hutchinson is given.

Ceratium hirundinella (O.F.Mull.) Bergh. 1882 [Translation from: Flora Slodkowodna Polski. Tom 4. Cryptophyceae, Dinophyceae, Raphidoiphyceae p395-400. Warsaw, Polska Academia Nauk, 1974]

Morphological observations of the dinoflagellate Ceratium hirundinella are given and a key to the difference in types provided. Illustrations are included.

Silenced angels: an obscure Saint Theresa in George Eliots Middlemarch

A presente dissertação objetiva a comparação proposta no Prelúdio do romance Middlemarch por sua autora George Eliot entre a protagonista da obra, Dorothea Brooke, e a figura histórica Teresa dÁvila. A partir de tal estudo, busca-se compreender de que modo a situação específica da mulher na Era Vitoriana é articulada no romance de modo a espelhar a crise ontológica e epistemológica do próprio ser humano diante das transformações consolidadas com o Iluminismo e as revoluções liberais do século XVIII que culminariam na morte de Deus. Dorothea mostra-se uma cristã tão fervorosa quanto a Teresa quinhentista, mas faltam-lhe certezas e a resolução para concretizar as reformas sociais que defende, pois ela encarna o mito de feminilidade oitocentista batizado de Anjo do Lar ideal de sujeição feminina à ordem falocêntrica cujas funções são a proteção e difusão da moralidade burguesa e a substituição de elementos cristãos no universo do sagrado a uma sociedade cada vez mais materialista e insegura de valores absolutos. As aflições de Dorothea representam as aflições da mulher vitoriana, mas o momento crítico desta mulher reflete, em Middlemarch, uma crise muito maior do Ocidente, que teve início com a Era da Razão