Conservación de la Biodiversidad: un reto del fin de siglo

Quines són les estratègies per a conèixer la diversitat biològica? Quina mena de relació hi ha entre biodiversitat i estructura funcional dels ecosistemes? A partir d'aquestes dues qüestions s'analitza la relació entre àrees protegides i conservació de la biodiversitat en les condicions demogràfiques, socials i econòmiques de la fi del segle xx, amb especial èmfasi en la situació que es presenta als països tropicals. Es planteja la necessitat de conservar la biodiversitat no solament a les àrees protegides, sinó també més enllà dels seus límits.What are the strategies used estimate to biological diversity? What is the relationship between biodiversity and the functional structure of ecosystems? The relationship between protected areas and the conservation of diversity is analyzed under the demographic, social and economic conditions of the end of the twentieth century, with a special emphasis on the situation in tropical countries. The idea that biodiversity must be conserved, not only in protected areas, but also outside of them is proposed.¿Cuáles son las estrategias para conocer la diversidad biológica? ¿Cuál es la relación entre biodiversidad y estructura funcional de los ecosistemas? A partir de estas dos preguntas se analiza la relación entre áreas protegidas y conservación de la biodiversidad en las condiciones demográficas, sociales y económicas del fin de siglo XX, con especial énfasis en la situación que se presenta en los países tropicales. Se plantea la necesidad de conservar la biodiversidad no sólo en las áreas protegidas, sino también fuera de ellas

COMPARATIVE ANALYSIS OF REPRODUCTIVE AND NESTING BEHAVIOR IN SEVERAL SPECIES OF EURYSTERNUS DALMAN (COLEOPTERA : SCARABAEINA E: EURY STERNINI)

This work aims at achieving a synthesis, and for this reason incorporates much unpublished information (more than 50% of all the data presented here). The goal is a better overall vision of nesting behavior and associated processes of the nine Eurysternus species for which data are available. Thus, we used not only published information, but also information from laboratory notebooks (covering 1967 to 2001) and observations on species never formally studied to date. Eurysternus, a morphologically quite homogeneous genus, shows two distinct types of nesting behavior (i.e., that of E. foedus, which makes brood-masses; and that of other Eurysternus species, so far as they are known, which make brood-balls), representing two directions in the evolution of Scarabaeinae nesting behavior. Beyond this, among the species showing the most common nesting behavior pattern—with several brood-balls integrated in a compound nest—some species care for their young after oviposition (subsocial species) while others do not. A review of data on a total of 307 Eurysternus pairs (representing seven species) maintained and studied in the laboratory, and four Huerta et al.: A nalysis comparative in several species of Eurysternus Eurysternus species (E. deplanatus, E. inflexus, E. jessopi, and E. magnus) whose nests were observed in the field demostrated that some species (though not all) develop two different types of nests (provisional or experimental, and definitive). Infanticide has also been observed, by the mother, by the father, and by both parents (for five of the nine species studied). While much is known in general about Eurysternus nesting behavior, synthesizing the data available raises new questions.Este artículo es un trabajo de síntesis, pero también incorpora mucha información inédita (más de un 50% del total). Para dar una nueva visión global de la nidificación en Eurysternus, utilizamos los datos ya publicados, la información reunida entre 1967 y 2001, conservada en los cuadernos de laboratorio, así como observaciones sobre especies nunca antes estudiadas. El propósito es presentar una visión de conjunto de la nidificación y de los procesos a ella asociados, en todas las especies de Eurysternus en donde se tiene información (9 especies). En un género muy homogéneo en su morfología, aparecen dos tipos de nidificación totalmente distintos (E. foedus que elabora masas-nido y las otras especies con nidificación conocida que fabrican bolas-nido) que corresponden a dos tendencias muy diferentes en la evolución de la nidificación dentro de los Scarabaeinae. Pero además, dentro de lo que sería el tipo de nidificación más representado: varias bolas-nido integrando un nido compuesto, aparecen especies con cuidados (subsociales) y sin cuidados post-oviposición. De la revisión de los datos obtenidos de 307 parejas mantenidas en el laboratorio y de cuatro especies cuyos nidos fueron observados en el campo, resalta la existencia en unas especies, pero no en todas, de dos tipos de nido (provisionales y definitivos), así como el infanticidio practicado por la madre, por el padre o por ambos progenitores. Sabemos realmente mucho de la nidificación de Eurysternus, pero la reunión de datos abre muchas preguntas nuevas

Local and regional ecological morphology of dung beetle assemblages across four biogeographic regions

Aim Niche partitioning within species assemblages is thought to influence species packing and/or total niche space occupied. The evolution of dung beetles (Scarabaeinae) is likely to have been strongly influenced by inter-specific competition, leading to niche partitioning. We consider whether local-scale processes leave a signature in regional patterns of functional diversity in dung beetle assemblages, and investigate the correlation between total exploited ecomorphological space and density of species packing with increased species richness. We test whether ecomorphological space occupied by local assemblages reflects that of their regional species pool, and the extent to which ecomorphological space is convergent or divergent within functional groups across regional pools. Location Neotropics, Africa, Australia and Madagascar. Methods Dung beetle assemblages were collected in a standardized manner from four biogeographic regions. Ecomorphological similarity among the assemblages was assessed by multivariate analysis of 19 linear measurements for 300 species and three functional nesting types (roller, tunneller or dweller), firstly on a local level within the Neotropics and Afrotropics, and then between the regional species pools. Results Key body measurements, in particular the hind tibia, separated rollers and tunnellers into largely non-overlapping entities along the first three axes of the shape analysis. Three Neotropical assemblages, which vary widely in species numbers, each harboured a similar amount of morphometric variation, resulting in increasingly dense species packing with greater species richness. Similar findings were obtained in two South African assemblages. Assemblages in the four biogeographic regions showed largely similar distributions of ecomorphological variation, including the separation of rollers and tunnellers, despite their distant phylogenetic relationships. Ecomorphological similarity among regions was particularly high in tunnellers, whilst the rollers exhibited greater regional differentiation. Main conclusions Local assemblages evidently represent the full diversity of functional groups available in the regional pool, even in species-poor assemblages. There is a strong trend towards convergence in morphology separating tunnellers and rollers in phylogenetically independent lineages. The ecomorphological similarity of regional assemblages suggests that morphological convergence is the result of common selective forces active within the assemblages themselves. This lends support to the widely hypothesized effect of inter-specific interactions and niche partitioning in determining assemblage composition and lineage evolution in the Scarabaeinae. © 2011 Blackwell Publishing Ltd

TOWARDS A CULTURE OF BIODIVERSITY CONSERVATION

This article is intended as a synthesis of the ideas, previously presented by the author, on the conservation of biodiversity as well as new proposals, heretofore unpublished. The author focusses on the central theme that in each society the ideas held about the use and the conservation of biodiversity and, in more general terms, about nature are an integral part of the culture of that society, and as such cannot be separated from its ethical and aesthetic values, or from its socio-economic reality. Three broad approaches to the protection and use of species richness are considered: rustic use, the establishment of protected areas and land use policy. Three types of protected areas are examined: hunting or game reserves, national parks and biosphere reserves. These conservation strategies appeared at different points in history in response to different needs and are therefore not mutually exclusive. They share the goal of protecting the exceptional richness of animals and plants within a delimited area. The problems facing these approaches, given the increasing evidence of spatial exchange of species, i.e. beta diversity, are examined. A single area is not enough to protect beta diversity, even when it is a big one. In response to this dilemma a completely new alternative is proposed, one that is complementary to the three currently in use – that of archipelago reserves.Este artículo pretende ser una síntesis de ideas antes expuestas por el autor sobre conservación de la biodiversidad y propuestas nuevas, inéditas, sobre el mismo tema. Una preocupación central ha sido señalar que en cada sociedad humana las ideas sobre uso y conservación de la biodiversidad y en términos más generales sobre la naturaleza, son parte de la cultura de esta sociedad y por lo tanto no pueden separarse de sus valores éticos y estéticos y de su realidad socioeconómica. Se consideran tres grandes enfoques en relación a la protección y uso de la riqueza de especies: el uso rústico, el establecimiento de áreas protegidas y el ordenamiento ambiental. Dentro del enfoque áreas protegidas se examinan tres modalidades, aparecidas en distintos momentos históricos y como respuesta a necesidades diferentes, modalidades no excluyentes entre sí. Son éstas, los cotos o reservas de caza, los parques nacionales y las reservas de la biosfera. Estas tres modalidades tienen en común el propósito de proteger una riqueza excepcional de animales y plantas dentro de un área espacial determinada. Se examinan los problemas que enfrentan en sus planteamientos ante la evidencia cada vez mayor del recambio espacial de especies: la diversidad beta. Para proteger la diversidad beta no es suficiente un área, así sea grande. Justamente como respuesta se plantea una alternativa totalmente nueva y complementaria a las anteriores: las reservas archipiélago

Gamma diversity: derived from and a determinant of alpha diversity and beta diversity. An analysis of three tropical landscapes

Using three taxonomic groups of beetles we examine how alpha and beta diversity influence the species richness of a landscape (gamma diversity), and vice versa. That is, how the species richness of a  landscape – which is a historical and biogeographical phenomenon –  contributes to the values of alpha diversity (1) at a given site, (2) in a community, (3) in terms of cumulative species richness by community, and also contributes to (4) the intensity of species exchange between  communities. To explore this question, we used two subfamilies of  Scarabaeoidea: Scarabaeinae and Geotrupinae, and the family  Silphidae. In all analyses these three taxonomic groups are considered  as a single indicator group: the copronecrophagous beetles.  Information is also included on the subfamily Aphodiinae  (Scarabaeoidea), coprophagous beetles not included in the indicator  group. Several types of vegetation located in three landscapes (tropical, transition and mountain) were studied, and these are located along an  altitudinal gradient in the central part of the state of Veracruz, Mexico.  We base this study on the following concepts. The alpha diversity of an  indicator group reflects the number of species that use a given  environment or resource in a given place or community. Spacial beta  diversityis related to the response of organisms to spatial  heterogeneity. Gamma diversity depends primarily on the historical and  geographic processes that operate on the mesoscale level and is  also affected by alpha and beta diversity. It is on this scale of landscape  that human actions, such as the modification and fragmentation of  vegetation, have their most important effects. These are, however, often  beyond the scope of ecological analyses carried out on a local  scale. In the three landscapes, sampling was carried out regularly at 67  sites, with complementary sampling at another 69 sites. Twenty-six  types of vegetation communities were studied. A total of 16,152  specimens representing 60 species were captured (52 species of  Scarabaeinae, 4 Geotrupinae and 4 Silphidae). In the tropical landscape  the community richest in species was low deciduous forest. In the  transition landscape, cloud forest was the richest. Each of these  communities is the most representative of their respective altitudinal  bands. In contrast, the greatest species richness in the mountain  landscape occurred in the mountain grasslands and pastures; types of  community favoured by or even created by human intervention. This is  explained by the expansion of heliophilous species from the Mexican  High Plateau into these areas. In the tropical landscape the species  richness of the pastures is similar to that of its forests, but with a  partially different composition which is characterized by the dominance  of heliophilous and coprophagous species; the latter, in addition to the  more ubiquitous species that are shared with the tropical forest. In the  transition landscape the cloud forest and the coffee plantations with  polyspecific shade are important in the context of conserving the fauna. This type of community offers arboreal cover and occupies the majority  of this landscape, allowing the groups of insects studied to move  between remnant fragments of cloud forest. On the landscape scale but  not locally, the fragmentation of natural communities does not  appear to have reduced the number of species for the beetles of the  indicator group. In each landscape disturbance by human activity  appears to have been overcome for distinct reasons. In the tropical  landscape we find the heliophilous beetle fauna characteristic of  pastures, and this has increased by two species of recent invaders. In  the transition landscape, the coffee plantations with polyspecific shade  create a communication matrix, while in the mountain landscape the  expansion of the mountain pastures has made conditions more  favourable for heliophilous species. These results are not necessarily  expected for other groups of organisms. Utilizando tres grupos taxonómicos en este trabajo examinamos como las diversidades alfa y beta influyen en la riqueza de especies de un  paisaje (diversidad gamma), así como el fenómeno recíproco. Es decir,  como la riqueza en especies de un paisaje (un fenómeno histórico-biogeográfico) contribuye a determinar los valores de la diversidad alfa  por sitio, por comunidad, la riqueza acumulada de especies por  comunidad y la intensidad del recambio entre comunidades. Los grupos utilizados son dos subfamilias de Scarabaeoidea: Scarabaeinae y  Geotrupinae, y la familia Silphidae. En todos los análisis los tres grupos  taxonómicos son manejados como un grupo indicador: los escarabajos  copronecrófagos. De una manera lateral se incluye información sobre la  subfamilia Aphodiinae (Scarabaeoidea), escarabajos coprófagos no  incorporados al manejo del grupo indicador. Los paisajes estudiados  son tres (tropical, de transición y de montaña), situados en un gradiente altitudinal en la parte central del estado de Veracruz. Partimos de las  premisas siguientes. La diversidad alfa de un grupo indicador refleja el  número de especies que utiliza un mismo ambiente o recurso en un  lugar o comunidad. La diversidad beta espacial se relaciona con la  respuesta de los organismos a la heterogeneidad del espacio. La  diversidad gamma depende fundamentalmente de los procesos  histórico-geográficos que actúan a nivel de mesoescala y está también  condicionada por las diversidades alfa y beta. Es a nivel de paisaje o  mesoescala donde las acciones humanas como cambio y fragmentación  de comunidades, tienen sus efectos más importantes,  efectos que en muchas ocasiones escapan al análisis ecológico puntual.  En el conjunto de los tres paisajes se realizaron muestreos  regulares en 67 sitios, más muestreos complementarios en 69 lugares  más. Se estudiaron 26 tipos de comunidades vegetales. Se capturó un  total de 16,152 ejemplares de 60 especies, 52 especies de Scarabaeinae,  4 de Geotrupinae y 4 de Silphidae. En el paisaje tropical  la comunidad más rica en especies es la selva baja caducifolia; en el  paisaje de transición es el bosque mesófilo. Ambas, son las  comunidades naturales más importantes de sus pisos altitudinales. Por  el contrario, en el paisaje de montaña la mayor riqueza se encuentra en  praderas y potreros, un tipo de comunidad favorecido o incluso creado  por la intervención humana. Esto se explica por la expansión a estos  lugares de especies heliófilas del Altiplano mexicano. En el paisaje  tropical los potreros presentan una riqueza en especies próxima a la de  las selvas, pero una composición parcialmente diferente, caracterizada  por la dominancia de especies heliófilas y coprófagas, a las que se  suman las especies más ubicuistas compartidas con la selva. En el  paisaje de transición se puso en relieve la importancia para la  conservación de la fauna del bosque mesófilo, de los cafetales de  sombra poliespecífica. Estos cafetales, el tipo de comunidad con  cubierta arbórea que ocupa la mayor superficie en este paisaje,  permiten a los grupos estudiados la intercomunicación entre los  fragmentos remanentes de bosque mesófilo. Para los escarabajos que  constituyen el grupo indicador, a nivel de paisaje (no puntualmente) la  fragmentación de las comunidades naturales no parece haber ocasionado pérdidas en el número de especies. Aparentemente, la  perturbación humana ha sido superada por razones distintas en cada  paisaje. En el tropical porque existe una fauna heliófila característica de  los potreros, fauna que incluso ha aumentado con dos especies  invasoras recientes. En el paisaje de transición por el efecto de los  cafetales de sombra poliespecífica que crean una matriz de  intercomunicación. En el de montaña porque la expansión de las  praderas ha ampliado las condiciones favorables para las especies heliófilas. Estos resultados no tienen forzosamente que repetirse con  otros grupos de organismos.&nbsp

Cambios a través del tiempo en una comunidad de escarabajos copronecrófagos (Insecta: Coleoptera: Scarabaeinae) como consecuencia de la modificación y fragmentación de un bosque tropical lluvioso

In order to determine the changes in biological diversity over time in different habitats of a fragmented tropical rain forest in Manaus, Brazil, we compared capture data from two windows in time: 1986 and 2000. We used beetles of the subfamily Scarabaeinae as an indicator group. Both sets of samples were collected from the same sites and following the same methodology. The only difference was that in 2000 most of the pastures that had been created as isolation barriers had been replaced by secondary vegetation in different stages of development. Beetles were collected from the following habitats: pasture, secondary vegetation, 1 ha, and 10 ha fragments of forest, and continuous rainforest. The main results follow. 1) After the dramatic decrease in Scarabaeinae species richness that followed the creation of the pastures and the isolation of the fragments there was a notable recovery of biodiversity. We associate this with the enormous tract of continuous rainforest that surrounds the study area since the sites were recolonized by rainforest species. 2) The high number of tourist species recorded for the pastures is evidence of the ease with which Scarabaeinae can overcome the physical barriers imposed by fragmentation. Over time, many of the tourist species coming from the intact forest can become colonizers. 3) Even when there is no human intervention, there is a high degree of heterogeneity in the spatial and temporal distributions of the Scarabaeinae in the rainforest. 4) For coprophagous beetles, the effects of forest fragmentation are a function of both forest fragment size and the nature of the matrix in which the fragments occur. In our study the development of secondary vegetation favored the connection between fragments and the continuous forest.Con el propósito de determinar los cambios en la diversidad biológica a través del tiempo en distintos hábitats de una selva lluviosa tropical fragmentada (Manaus, Brasil), comparamos dos ventanas: la primera correspondiente a las capturas realizadas en 1986, y la segunda en 2000. Como grupo indicador usamos los escarabajos de la subfamilia Scarabaeinae. En las dos ventanas, las colectas se realizaron en los mismos sitios y siguiendo la misma metodología. La única diferencia fue que para el 2000, la mayor parte de los pastizales establecidos como barreras de aislamiento habían sido remplazados por vegetación secundaria con distintos grados de desarrollo. Se colectó en los siguientes hábitats: pastizal, vegetación secundaria, fragmentos de bosque de 1 ha, y 10 ha, bosque original continuo. Los principales resultados fueron: 1) Después de la reducción drástica en la riqueza de especies de Scarabaeinae que siguió a la creación de los pastizales y al aislamiento de los fragmentos, se presentó una importante recuperación de la biodiversidad. Este fenómeno lo asociamos a la enorme extensión de selva continua que rodea al área de estudio, ya que la recolonización ocurrió con especies de selva. 2) El alto número de especies turistas encontradas en los pastizales es evidencia de la facilidad con que los Scarabaeinae saltan las barreras físicas impuestas por la fragmentación. Con el tiempo, al repetirse los casos, muchas especies turistas que proceden del bosque continuo pueden convertirse en colonizadoras. 3) Aún sin ninguna intervención humana, existe un alto grado de heterogeneidad en las distribuciones espacial y temporal de los Scarabaeinae en la selva tropical lluviosa. 4) En lo que respecta a los efectos de la fragmentación del bosque sobre los escarabajos coprófagos, además de la extensión de los fragmentos, es importante la naturaleza de la matriz en que éstos quedan incluidos. En nuestro estudio el desarrollo de la vegetación secundaria favoreció la interconexión entre los fragmentos y el bosque continu

Nuevos datos sobre canthon (coleoptera: scarabaeinae) de Chiapas, México

For the genus Canthon, a new species (C. lucreciae) is described; for the first time the presence of a second species in Chiapas, Mexico is indicated; as is the presence of two more species previously only known as one record.Dentro del género Canthon se describe una nueva especie (C. lucreciae), se señala por primera vez la presencia en Chiapas de una segunda especie y se confirma la de dos más conocidas hasta la fecha por un solo registro

Gamma diversity: derived from and a determinant of alpha diversity and beta diversity. An analysis of three tropical landscapes

Using three taxonomic groups of beetles we examine how alpha and beta diversity influence the species richness of a landscape (gamma diversity), and vice versa. That is, how the species richness of a landscape ? which is a historical and biogeographical phenomenon ? contributes to the values of alpha diversity (1) at a given site, (2) in a community, (3) in terms of cumulative species richness by community, and also contributes to (4) the intensity of species exchange between communities. To explore this question, we used two subfamilies of Scarabaeoidea: Scarabaeinae and Geotrupinae, and the family Silphidae. In all analyses these three taxonomic groups are considered as a single indicator group: the copronecrophagous beetles. Information is also included on the subfamily Aphodiinae (Scarabaeoidea), coprophagous beetles not included in the indicator group. Several types of vegetation located in three landscapes (tropical, transition and mountain) were studied, and these are located along an altitudinal gradient in the central part of the state of Veracruz, Mexico. We base this study on the following concepts. The alpha diversity of an indicator group reflects the number of species that use a given environment or resource in a given place or community. Spacial beta diversity is related to the response of organisms to spatial heterogeneity. Gamma diversity depends primarily on the historical and geographic processes that operate on the mesoscale level and is also affected by alpha and beta diversity. It is on this scale of landscape that human actions, such as the modification and fragmentation of vegetation, have their most important effects. These are, however, often beyond the scope of ecological analyses carried out on a local scale. In the three landscapes, sampling was carried out regularly at 67 sites, with complementary sampling at another 69 sites. Twenty-six types of vegetation communities were studied. A total of 16,152 specimens representing 60 species were captured (52 species of Scarabaeinae, 4 Geotrupinae and 4 Silphidae). In the tropical landscape the community richest in species was low deciduous forest. In the transition landscape, cloud forest was the richest. Each of these communities is the most representative of their respective altitudinal bands. In contrast, the greatest species richness in the mountain landscape occurred in the mountain grasslands and pastures; types of community favoured by or even created by human intervention. This is explained by the expansion of heliophilous species from the Mexican High Plateau into these areas. In the tropical landscape the species richness of the pastures is similar to that of its forests, but with a partially different composition which is characterized by the dominance of heliophilous and coprophagous species; the latter, in addition to the more ubiquitous species that are shared with the tropical forest. In the transition landscape the cloud forest and the coffee plantations with polyspecific shade are important in the context of conserving the fauna. This type of community offers arboreal cover and occupies the majority of this landscape, allowing the groups of insects studied to move between remnant fragments of cloud forest. On the landscape scale but not locally, the fragmentation of natural communities does not appear to have reduced the number of species for the beetles of the indicator group. In each landscape disturbance by human activity appears to have been overcome for distinct reasons. In the tropical landscape we find the heliophilous beetle fauna characteristic of pastures, and this has increased by two species of recent invaders. In the transition landscape, the coffee plantations with polyspecific shade create a communication matrix, while in the mountain landscape the expansion of the mountain pastures has made conditions more favourable for heliophilous species. These results are not necessarily expected for other groups of organisms

Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient

We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide