A5079137949- Ecology and Vegetation Dynamics Studies
- African Botany and Ecology Studies
- International Relations and Foreign Policy
- Conservation, Biodiversity, and Resource Management
- Forest ecology and management
- Plant Diversity and Evolution
- Plant Water Relations and Carbon Dynamics
- Plant and animal studies
- Military History and Strategy
- Defense, Military, and Policy Studies
- Fire effects on ecosystems
- Military and Defense Studies
- Distributed and Parallel Computing Systems
- Teaching and Learning Programming
- Chinese history and philosophy
- Agroforestry and silvopastoral systems
- Botany and Plant Ecology Studies
- Species Distribution and Climate Change
- Plant Parasitism and Resistance
- Agriculture and Rural Development Research
- Forest Management and Policy
- Economic Zones and Regional Development
- Hong Kong and Taiwan Politics
- Mediterranean and Iberian flora and fauna
- Seed Germination and Physiology
University of Aberdeen
2012-2025
James Cook University
2021
Institute of Biological, Environmental and Rural Sciences
2020
Aberystwyth University
2020
Carnegie Endowment for International Peace
2018
Oxfam
1996
Triangle
1993
In-Q-Tel
1992
RAND Corporation
1991
Commonwealth Secretariat
1985-1986
It is a privilege to be asked and pleasurable duty for me write the foreword of this book. The conservation wise utilisation humid tropical forests, unique biome, are matters great concern importance millions living within around these forests and, perhaps, less directly, totality mankind. These provide many essential products services list lengthy need not repeated here. Suffice it say that there aspects human activity which do utilise some products, or derivatives therefrom. Yet view those...
Abstract The future of tropical forests under global environmental change is uncertain, with biodiversity and carbon stocks at risk if precipitation regimes alter. Here, we assess changes in plant functional composition biomass 19 plots from a variety forest types during two decades long‐term drought Ghana. We find consistent increase dry forest, deciduous, canopy species intermediate light demand concomitant decrease wet evergreen, sub‐canopy shade‐tolerant species. These are accompanied by...
Abstract. The climate, soil, structure and floristics of dry forests in West Africa are summarised. Data from Ghana show that these have two-peak annual rainfall between 850 1350 mm, with 6–10 months (< 100 mm rain) each year; by relatively nutrient-rich soils developed over a variety rock types; short stature (tallest trees 10-40 m) high deciduousness the upper canopy evergreenness understorey; distinctive flora which changes gradually towards areas higher but abruptly at forest-savanna...
Abstract. The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these account for more assimilation and storage than any other terrestrial ecosystem. Based on a unique combination pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements 35 litter measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) climate, we ask how allocation are related to seasonality...
Significance We develop a biogeographic approach to analyzing the presence of alternative stable states in tropical biomes. Whilst forest–savanna bistability has been widely hypothesized and modeled, empirical evidence remained scarce controversial, here, applying our method Africa, we provide large-scale that there are tree species composition vegetation. Furthermore, results have produced more accurate maps forest savanna distributions which take into account differences composition,...
ABSTRACT Seasonal changes in the densities of dormant seeds soil around eight pioneer trees 50-ha Forest Dynamics Plot, on Barro Colorado Island, Panamá were studied, and how seed dispersal dormancy influenced patterns abundance distribution examined. Twenty-four, 3-cm-deep samples collected 30 m transects radiating out from each four time-intervals through year, 21-cm-deep beneath focal tree crowns. In surface 0–3 cm soil, germinable all species combined declined a peak 1090 −2 mid-wet...
1. The West African tree species Albizia zygia, Blighia sapida, Celtis mildbraedii, Chrysophyllum pruniforme, Cynometra ananta, Guarea cedrata, Heritiera utilis, Lophira alata, Mansonia altissima, Milicia excelsa, Pericopsis elata, Pterygota macrocarpa, Strombosia glaucescens, Terminalia ivorensis and Triplochiton scleroxylon, which represent different ecological guilds (pioneers, non-pioneer light-demanders shade-bearers) distributions on a rainfall soil fertility gradient were tested for...
Summary 1 Soil and plant-water relations were studied in a canopy opening surrounding forest shade moist tropical Ghana using seedlings of two tree species with different regeneration strategies, the pioneer Terminalia superba nonpioneer light demander Entandrophragma utile. 2 During consecutive dry seasons, soil matric potential varied from -30 kPa at end rainy season, to below -2.5 MPa middle season. part first season was higher gap than forest. In second no differences observed. 3 Leaf...
Summary 1 Seed germination in light and dark, responses to irradiance quality, were tested shadehouse experiments for 19 West African tropical forest tree species representing a wide range of ecological types. Germination gaps different size was 11 species. 2 Percentage reduced the dark only three small‐seeded that are common soil seed banks: Musanga cecropioides , Nauclea diderrichii Milicia excelsa . other 16 species, including four widely regarded as ‘pioneers’, unaffected. 3 Effects...
Summary 1 Seedlings of 16 West African timber tree species were grown in six neutral shadehouses with irradiances 2%, 6%, 10%, 28%, 44% and 66% unshaded values. 2 Tested included well‐known pioneers, which showed negative growth 2% irradiance but responded strongly to increased irradiance, very shade‐tolerant non‐pioneers, had positive only slightly irradiance. 3 For all species, maximum occurred at an varying between 10% 44%. The inhibition higher was greater the more species. 4 Data from...
China's continuing rapid economic growth and expanding involvement in global affairs pose major implications for the power structure of international system. To more accurately fully assess significance emergence United States community, it is necessary to gain a complete understanding Chinese security thought behavior. This study addresses such questions as: What are most fundamental national objectives? How has state employed force diplomacy pursuit these objectives over centuries?...
The results described are of the effects fire exclusion since 1957 on a small area savanna close to forest-zone boundary, northern Accra Plains, Ghana. A forest thicket has developed, with species in intimate association nonforest species. component includes healthy regeneration important timber species, Milicia (= Chlorophora) excelsa (Benth. & Hook.) Berg (nomenclature follows Hutchinson Dalziel [1954-721 except where authorities given) (max. 114 cm gbh) and Antiaris toxicaria Lesch. (53...
Topsoil samples were collected from two 1 m2 quadrats in six mature forest sites, each representative of a Ghanaian type, and regularly watered to promote seed germination. Each sample was subdivided; half the subsamples exposed full sunshine, while other shaded until germination ceased then transferred sun. A total 2028 seedlings belonging 90 species (of which only 10 occur forest) recorded sunlit boxes. Only 120 seedlings, 25 species, germinated shade, but further 41 when boxes...
Baboon dung was collected in the Shai Hills, Ghana at 4—wk intervals from November 1975 to January 1977, and planted sterilized soil order estimate viable seed content of dung. A total 6,465 seedlings germinated, belonging 59 species, although 70% belonged 2 fleshy—fruited species. The species composition varied month as did relative importance dry fruits. Germination ingested seeds (removed dung) significantly improved over that fresh 3 4 tested (Securinega virosa, Azadirachta indica,...
ABSTRACT Early studies comparing adult and juvenile tree populations in West Africa described a contrast flonstic composition between the two age classes. These have been mis-represented more recent literature, confusion has arisen over their interpretation. Similar comparisons are reported here for six forest sites Ghana. At any one site, clear differences were recognized samples, but terms of variation whole zone, they slight types appear to ‘breed true’. Kade, compositional size classes...
(1) Three plots in Northern Guinea savanna were enumerated and then clearfelled 1950. Since one plot has been completely protected, a second burnt annually early the dry season, third late season. (2) In 1976-77 there 202 trees ha-' (? 30 cm girth) on protected plot, forty-two ha twenty plot. Corresponding figures for basal area are 3-43, 0-51, 0.24 m2 ha-'. (3) The of grass both remained constant at about 13% since 1960 whereas continued to decline was 6.3% 1976. Grass biomass end growing...