An opportunity to investigate in advance of new construction led to the discovery of five Mesolithic hazel fish traps some 6.3m below mean sea level in the River Liffey. Closely paralleled on the continent of Europe they imply a well... more
An opportunity to investigate in advance of new construction led to the discovery of five Mesolithic hazel fish traps some 6.3m below mean sea level in the River Liffey. Closely paralleled on the continent of Europe they imply a well organised community that knew how to catch fish using the tide, to make wattle-work and baskets and who undertook coppicing on an eight year cycle in about 6100-5700 cal BC. The likelihood of more Mesolithic remains under European towns that have remained attractive to fishers and settlers has considerable implications for Cultural Resource Management. Do we always know how to find and access such delicate and important traces?
This paper charts the emergence of the concept of Ancient Woodland in the British context and its incorporation into public policy. The basis of the policy is examined and found to be at odds with the science and landscape history through... more
This paper charts the emergence of the concept of Ancient Woodland in the British context and its incorporation into public policy. The basis of the policy is examined and found to be at odds with the science and landscape history through which it is justified . Finally it considers how such a situation may have arisen and promotes a new dialogue between foresters and conservationists based on shared goals and understanding.
Photosynthetic leaf traits were determined for savanna and forest ecosystems inWest Africa, spanning a large range in precipitation. Standardized major axis fits revealed important differences between our data and reported global... more
Photosynthetic leaf traits were determined for savanna and forest ecosystems inWest Africa, spanning a large range in precipitation. Standardized major axis fits revealed important differences between our data and reported global relationships. Especially for sites in the drier areas, plants showed higher photosynthetic rates for a given N or P when compared with relationships from the global data set. The best multiple regression for the pooled data set estimated Vcmax and Jmax from NDW and S.However, the best regression for different vegetation types varied, suggesting that the scaling of photosynthesis with leaf traits changed with vegetation types.A new model is presented representing independent constraints by N and P on photosynthesis, which can be evaluated with or without interactions with S. It assumes that limitation of photosynthesis will result from the least abundant nutrient, thereby being less sensitive to the allocation of the non-limiting nutrient to nonphotosynthetic pools. The model predicts an optimum proportionality for N and P, which is distinct for Vcmax and Jmax and inversely proportional to S. Initial tests showed the model to predict Vcmax and Jmax successfully for other tropical forests characterized by a range of different foliar N and P concentrations.
Besancon est en France metropolitaine la ville de plus de 100 000 habitants avec le plus fort taux d’espaces verts par habitant. La foret de Chailluz, qui existe depuis plus de six siecles, forme pres des 3/4 de sa surface forestiere.... more
Besancon est en France metropolitaine la ville de plus de 100 000 habitants avec le plus fort taux d’espaces verts par habitant. La foret de Chailluz, qui existe depuis plus de six siecles, forme pres des 3/4 de sa surface forestiere. Aucune recherche scientifique ne rendait encore compte de la nature et de la valeur de son patrimoine archeologique. Un des objectifs de cette etude est de detecter, identifier et documenter le patrimoine historique et archeologique de la foret de Chailluz pour permettre in fine sa valorisation aupres du grand public. Cette these contribue aussi a la reflexion collective menee dans divers programmes de recherche (LIEPPEC, ODIT - MSHE C.N. Ledoux ; LEA ModeLTER), qui visent a developper des methodes de traitement de donnees altimetriques a haute resolution pour une analyse des paysages dans la longue duree (LIEPPEC), a conduire des recherches avancees en termes de concepts et de methodes sur les dynamiques socio-environnementales dans la longue duree (M...
The Frankincense tree Boswellia papyrifera is an important resource in the semiarid lower highlands of eastern Africa but its populations are declining due to human pressure and environmental degradation. To assess the perspectives of... more
The Frankincense tree Boswellia papyrifera is an important resource in the semiarid lower highlands of eastern Africa but its populations are declining due to human pressure and environmental degradation. To assess the perspectives of (assisted) natural regeneration for Boswellia woodland restoration, we examined Boswellia stand structure and seedling densities in a grazed woodland and in a livestock grazing exclosure. We also tested topsoil scarification as a means to increase seedling survival.Boswellia populations lacked small diameters, indicating recruitment limitation. During the rainy season, seedling densities were 8331 ha−1 in the exclosure and 3325 ha−1 in the grazed woodland. Respectively, 19% and 11% of these seedlings survived the first dry season. However, the lack of saplings suggests a lack of surviving seedlings over successive dry seasons and thus a cumulative seedling mortality approximating 100% within each generation. Topsoil scarification had an adverse effect on seedling survival.Dry season seedling mortality seriously limits the potential of natural Boswellia woodland recovery. To restore a healthy population structure in exclosures, additional management interventions such as shading to support early seedling survival or planting of large rooted cuttings need to be tested.
Woodlands in Ethiopia are under heavy pressure and shrinking overtime. Despite the woodland’s economic and ecological importance’s, little attention has been given to monitor the condition of the resources through time. The aim of this... more
Woodlands in Ethiopia are under heavy pressure and shrinking overtime. Despite the woodland’s economic and ecological importance’s, little attention has been given to monitor the condition of the resources through time. The aim of this study is to assess the status of western dry woodlands of Ethiopia by analyzing land use and land cover (LULC) dynamics and recommend their future sustainable management and development in view of their multi-functions, climate change mitigation potentials as well as local livelihood improvement. Remote sensing (RS) and Geographic Positioning System (GIS) were used to assess the LULC dynamics in three regional states (Amhara, Tigray, and Benshangul-Gumz). Three study sites: Metema, Kafta-Humera and Sherkole were selected, respectively. In all study sites the classes of agricultural land and bare land have expanded at an average rate of 2322.9 and 726.6 ha/year, respectively. On the other hand, the woodland cover in the three districts was decreasing a...
The rapid expansion of urban areas worldwide is leading to native habitat loss and ecosystem fragmentation and degradation. Although the study of urbanisation's impact on biodiversity is gaining increasing interest globally, there is... more
The rapid expansion of urban areas worldwide is leading to native habitat loss and ecosystem fragmentation and degradation. Although the study of urbanisation's impact on biodiversity is gaining increasing interest globally, there is still a disconnect between research recommendations and urbanisation strategies. Expansion of the Perth metropolitan area on the Swan Coastal Plain in south-western Australia, one of the world's thirty-six biodiversity hotspots, continues to affect the Banksia Woodlands (BWs) ecosystem, a federally listed Threatened Ecological Community (TEC). Here, we utilise the framework of a 1989 review of the state of knowledge of BWs ecology and conservation to examine scientific advances made in understanding the composition, processes and functions of BWs and BWs' species over the last 30 years. We highlight key advances in our understanding of the ecological function and role of mechanisms in BWs that are critical to the management of this ecosystem...