Dalsgaard B, Martín González A M, Olesen J M, Ollerton J, Timmermann A, Andersen L H, Tossas AG (2009) Plant-hummingbird interactions in the West Indies: floral specialization gradients associated with environment and hummingbird size. Oecologia 159: 757-766.
Clavero M, Brotons L, Pons P, Sol S (2009) Prominent role of invasive species on global avian biodiversity loss. Conservation Biology 142: 2043-2049.
Kumschick S, Schmidt-Entling M S, Bacher S, Hickler T, Espadaler X, Nentwig W (2009) Determinants of local ant (Hymenoptera: Formicidae) species richness and activity density in Europe. Ecological Entomology 34: 748-754.
Demagrée GR, Ruthishauser T (2009) Origins of the Word "Phenology". Eos 90: 291.
Martín González A M, Dalsgaard B, Olesen J M, Ollerton J, Timmermann A, Andersen L H, Tossas AG (2009) Effects of climate on pollination networks in the West Indies. Journal of Tropical Ecology 25: 493-506.
Armenteras D., Rodríguez N., Retana J. (2009) Are conservation strategies effective in avoiding the deforestation of the Colombian Guyana Shield?. Biological Conservation. 142: 1411-1419.EnllaçDoi: 10.1016/j.biocon.2009.02.002
There is general agreement regarding the importance of analysing the territories' roles under different biodiversity management figures in order to support better decision making in the management of natural resources in tropical countries. In this study we analyse the deforestation process to address the question of whether existing strategies such as national protected areas (PAs) and indigenous reservations (IRs) are effective protecting forests in the Colombian Guyana shield. We analyse whether these territories have successfully halted deforestation and agricultural frontier expansion by comparing deforestation occurring within these areas with their surroundings from 1985 to 2002. We also evaluate the impact of roads, illicit crops, and the size of PAs and IRs on deforestation rates. The results indicate that deforestation levels along the outside borders of both management figures were almost four times higher than inside declared PAs and 1.5 times higher than in IRs. However, within IRs, the loss of forested ecosystems was approximately six times greater than inside national parks. As a whole, roads were a significant factor associated with the changes in the region, as well as the influential expansion of coca cultivation particularly outside the national parks. The size of the PAs and indigenous lands also determined their positive impact as barrier against deforestation. Our results suggest strong pressure on areas surrounding PAs, driven by economic forces such as illegal crop expansion, particularly in the last decade. Indigenous lands with small territories have suffered intensive deforestation processes since the 1980s, but changes have been less dramatic in larger areas. Today, PAs are an effective barrier to deforestation, especially given their large extension, but are still under high risk. Future management plans should consider a designed infrastructure development paired with the establishment of new indigenous reservations with minimum viable sizes in order to control accessibility, natural resources extraction, and deforestation. © 2009 Elsevier Ltd. All rights reserved.
Arnan X., Gracia M., Comas L., Retana J. (2009) Forest management conditioning ground ant community structure and composition in temperate conifer forests in the Pyrenees Mountains. Forest Ecology and Management. 258: 51-59.EnllaçDoi: 10.1016/j.foreco.2009.03.029
The search for indicators to monitor management impact on biodiversity is a crucial question because management practices promote changes in community structure and composition of different animal groups. This study explores the effect of widely conducted management practices (forest logging and livestock) in Pinus uncinata forests in the Pyrenees range (NE Spain) on the structure and composition of ground ant communities compared to those of old-growth stands. Forest structure clearly differed in stands with different forest managements. These stands managed for different uses also showed marked differences in structure and composition of ground ant communities. There was a great dominance of a single species, Formica lugubris, which accounted for 99% of ants collected in pitfall traps. Rarefaction curves indicated that species richness was highest in old-growth stands and lowest in even-aged ones, with woodland pasture stands showing an intermediate value. Classification methods allowed us to identify two groups of species: six species related to old-growth plots and three species (including F. lugubris) associated to managed stands. Habitat structure played an important role in determining the structure of ant communities: forests with high tree density but low basal area were the most favourable forest type for F. lugubris, while the abundance of the remaining ant species was negatively affected by the abundance of F. lugubris and by tree cover. © 2009.
Bartomeus I., Vil̀ M. (2009) Breeding system and pollen limitation in two supergeneralist alien plants invading Mediterranean shrublands. Australian Journal of Botany. 57: 109-115.EnllaçDoi: 10.1071/BT08169
Many widely known invasive plants are well integrated into native plant-pollinator networks. Typically, these invaders have entomophilous flowers which are visited by a diverse array of pollinators. The type of breeding system and the role that pollination services play in the reproductive success of invasive plants have, however, received little attention. We studied the breeding system and pollen limitation of two entomophilous invasive plants, Carpobrotus affine acinaciformis and Opuntia stricta, in different Mediterranean coastal localities in north-eastern Spain. Both species are, to some degree self-compatible; however, because of frequent visitation, open pollination increased the seed set in both species by at least 50%. Whereas O. stricta showed no pollen limitation, some populations of C. aff. acinaciformis had a lower seed set in open-pollinated flowers than in flowers where supplementary hand-pollination ensured out-crossing. This local pollen limitation in C. aff. acinaciformis could be due to the low efficiency of its visitors (mainly beetles) or its hybrid status. On the basis of previous studies on Carpobrotus sp. hybrid complexes, we suggest that the variability among sites in the seed set of open-pollinated flowers is caused by different degrees of hybrid introgression. Not withstanding, we found the C. aff. acinaciformis seed sets studied were higher than those reported in other regions. Further research is needed to assess the invasion potential of these hybrids in Mediterranean shrublands. © 2009 CSIRO.
Beier C., Emmett B.A., Tietema A., Schmidt I.K., Penũelas J., Láng E.K., Duce P., De Angelis P., Gorissen A., Estiarte M., De Dato G.D., Sowerby A., Kröel-Dulay G., Lellei-Kovács E., Kull O., Mand P., Petersen H., Gjelstrup P., Spano D. (2009) Carbon and nitrogen balances for six shrublands across Europe. Global Biogeochemical Cycles. 23: 0-0.EnllaçDoi: 10.1029/2008GB003381
Shrublands constitute significant and important parts of European landscapes providing a large number of important ecosystem services. Biogeochemical cycles in these ecosystems have gained little attention relative to forests and grassland systems, but data on such cycles are required for developing and testing ecosystem models. As climate change progresses, the potential feedback from terrestrial ecosystems to the atmosphere through changes in carbon stocks, carbon sequestration, and general knowledge on biogeochemical cycles becomes increasingly important. Here we present carbon and nitrogen balances of six shrublands along a climatic gradient across the European continent. The aim of the study was to provide a basis for assessing the range and variability in carbon storage in European shrublands. Across the sites the net carbon storage in the systems ranged from 1,163 g C m-2 to 18,546 g C m-2, and the systems ranged from being net sinks (126 g C m -2 a-1) to being net sources (-536 g C m-2 a-1) of carbon with the largest storage and sink of carbon at wet and cold climatic conditions. The soil carbon store dominates the carbon budget at all sites and in particular at the site with a cold and wet climate where soil C constitutes 95% of the total carbon in the ecosystem. Respiration of carbon from the soil organic matter pool dominated the carbon loss at all sites while carbon loss from aboveground litter decomposition appeared less important. Total belowground carbon allocation was more than 5 times aboveground litterfall carbon which is significantly greater than the factor of 2 reported in a global analysis of forest data. Nitrogen storage was also dominated by the soil pools generally showing small losses except when atmospheric N input was high. The study shows that in the future a climate-driven land cover change between grasslands and shrublands in Europe will likely lead to increased ecosystem C where shrublands are promoted and less where grasses are promoted. However, it also emphasizes that if feedbacks on the global carbon cycle are to be predicted it is critically important to quantify and understand belowground carbon allocation and processes as well as soil carbon pools, particularly on wet organic soils, rather than plant functional change as the soil stores dominate the overall budget and fluxes of carbon. Copyright 2009 by the American Geophysical Union.
Blanch J.-S., Peñuelas J., Sardans J., Llusià J. (2009) Drought, warming and soil fertilization effects on leaf volatile terpene concentrations in Pinus halepensis and Quercus ilex. Acta Physiologiae Plantarum. 31: 207-218.EnllaçDoi: 10.1007/s11738-008-0221-z
The changes in foliar concentrations of volatile terpenes in response to water stress, fertilization and temperature were analyzed in Pinus halepensis and Quercus ilex. The most abundant terpenes found in both species were α-pinene and Δ3-carene. β-Pinene and myrcene were also abundant in both species. P. halepensis concentrations were much greater than those of Q. ilex in agreement with the lack of storage in the latter species (15205.60 ± 1140.04 vs. 0.54 ± 0.08 μg g-1 [d.m.]). The drought treatment (reduction to 1/3 of full watering) significantly increased the total terpene concentrations in both species (54% in P. halepensis and 119% in Q. ilex). The fertilization treatment (addition of either 250 kg N ha-1 or 250 kg P ha-1 or both) had no significant effects on terpene foliar concentrations. The terpene concentrations increased from 0.25 μg g-1 [d.m.] at 30°C to 0.70 μg g-1 [d.m.] at 40°C in Q. ilex (the non-storing species) and from 2,240 μg g-1 [d.m.] at 30°C to 15,621 μg g-1 [d.m.] at 40°C in P. halepensis (the storing species). Both species presented negative relationship between terpene concentrations and relative water contents (RWC). The results of this study show that higher terpene concentrations can be expected in the warmer and drier conditions predicted for the next decades in the Mediterranean region. © 2008 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences.
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