16 documents found, page 1 of 2
Is there solid evidence of widespread landscape disturbance in the Azores befor...
Elias, Rui B.; Connor, Simon; Góis-Marques, Carlos A.; Schaefer, Hanno; Silva, Luís; Sequeira, Miguel M.; Moura, Mónica; Borges, Paulo A. V.Raposeiro et al. conclude that human occupation of the Azores islands began between 700 and 850 CE, causing widespread landscape disturbance and raising doubts about the islands’ presumed pristine nature when the Portuguese arrived. However, previous paleoecological studies from Flores, Pico, and Sao Miguel Islands (Table 1) show that permanent changes in the vegetation occurred only after the early 15th centur...
The human dimension of biodiversity changes on islands
Nogué, Sandra; Santos, Ana M. C.; Birks, H. John B.; Björck, Svante; Castilla-Beltrán, Alvaro; Connor, Simon; de Boer, Erik J.; Nascimento, Lea deIslands are among the last regions on Earth settled and transformed by human activities, and they provide replicated model systems for analysis of how people affect ecological functions. By analyzing 27 representative fossil pollen sequences encompassing the past 5000 years from islands globally, we quantified the rates of vegetation compositional change before and after human arrival. After human arrival, rate...
Drought, fire and grazing precursors to large-scale pine forest decline
Connor, Simon; Araújo, João; Boski, Tomasz; Gomes, Ana; Gomes, Sandra D.; Leira, Manel; Freitas, Maria da Conceição; Andrade, CesarAim Temperate forests are currently facing multiple stresses due to climate change, biological invasions, habitat fragmentation and fire regime change. How these stressors interact with each other influences how, when and whether ecosystems recover, or whether they adapt or transition to a different ecological state. Because forest recovery or collapse may take longer than a human lifetime, predicting the outco...
Holocene sea level and climate interactions on wet dune slack evolution in SW P...
Leira, Manel; Freitas, Maria C.; Ferreira, Tania; Cruces, Anabela; Connor, Simon; Andrade, Cesar; Lopes, Vera; Bao, RobertoWe examine the Holocene environmental changes in a wet dune slack of the Portuguese coast, Poco do Barbarroxa de Baixo. Lithology, organic matter, biological proxies and high-resolution chronology provide estimations of sediment accumulation rates and changes in environmental conditions in relation to sea-level change and climate variability during the Holocene. Results show that the wet dune slack was formed 7...
Long-term population dynamics: Theory and reality in a peatland ecosystem
Connor, Simon; Colombaroli, Daniele; Confortini, Federico; Gobet, Erika; Ilyashuk, Boris P.; Ilyashuk, Elena A.; van Leeuwen, Jacqueline F. N.1. Population dynamics is a field rich in theory and poor in long-term observational data. Finding sources of long-term data is critical as ecosystems around the globe continue to change in ways that current theories and models have failed to predict. Here we show how long-term ecological data can improve our understanding about palaeo-population change in response to external environmental factors, antecedent ...
Potential natural vegetation and pre-anthropic pollen records on the Azores Isl...
Rull, Valenti; Connor, Simon; Elias, Rui B.This paper discusses the concept of potential natural vegetation (PNV) in the light of the pollen records available to date for the Macaronesian biogeographical region, with emphasis on the Azores Islands. The classical debate on the convenience or not of the PNV concept has been recently revived in the Canary Islands, where pollen records of pre-anthropic vegetation seemed to strongly disagree with the existin...
Preface: Guadiana river estuary. Investigating the past, present and future
Connor, SimonEstuaries are some of the most dynamic and complex environments in the world. The places where rivers meet the sea are subject to cycles of constant change – from the waves and currents that move particles of sand and mud every second, to the daily ebb and flow of the tides and the more dramatic effects of periodic floods, droughts and storms. Over thousands of years, estuaries are created, destroyed and recrea...
Modern diatom assemblages as tools for paleoenvironmental reconstruction: a cas...
Gomes, Ana; Boski, T.; Moura, Delminda; Szkornik, Katie; Witkowski, Andrzej; Connor, Simon; Laut, Lazaro; Sobrinho, Frederico; Oliveira, SóniaDiatoms are unicellular algae that live in saline, brackish and freshwater environments, either floating in the water column or associated with various substrates (e.g., muddy and sandy sediments). Diatoms are sensitive to changes in environmental variables such as salinity, sediment texture, nutrient availability, light and temperature. This characteristic, along with their short lifespan, allows diatoms to qu...
How old is the Tasmanian cultural landscape? a test of landscape openness using...
Mariani, Michela; Connor, Simon; Fletcher, Michael-S.; Theuerkauf, Martin; Kunes, Petr; Jacobsen, Geraldine; Saunders, Krystyna M.; Zawadzki, AtunAim: To test competing hypotheses about the timing and extent of Holocene landscape opening using pollen-based quantitative land-cover estimates. Location: Dove Lake, Tasmanian Wilderness World Heritage Area, Australia. Methods: Fossil pollen data were incorporated into pollen dispersal models and corrected for differences in pollen productivity among key plant taxa. Mechanistic models (REVEALS-Regional Estimat...
Paleoenvironmental evolution of the Guadiana Estuary, Portugal, during the Holo...
Camacho, Sarita; Boski, T.; Moura, Delminda; Scott, David; Connor, Simon; Pereira, LauraIn this paper, we reconstruct the Holocene paleoenvironmental evolution of the Guadiana Estuary, southwestern Iberian Peninsula. Two previously studied boreholes (CM3 and CM5) were revisited and analyzed in the light of a foraminifera modern analog approach. Cluster analyses define four assemblages with different biocenotic, taphonomic, elevation and distance-to-sea settings, which serve as a baseline for paleo...