Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

:The carbon sink capacity of the world’s agricultural and degraded soils is 50 to 66% of the historic carbon loss of 42 to 78 gigatons of carbon. The rate of soil organic carbon sequestration with adoption of recommended technologies depends on soil texture and structure, rainfall, temperature, farming system, and soil management. Strategies to increase the soil carbon pool include soil restoration and woodland regeneration, no-till farming, cover crops, nutrient management, manuring and sludge application, improved grazing, water conservation and harvesting, efficient irrigation, agroforestry practices, and growing energy crops on spare lands. An increase of 1 ton of soil carbon pool of degraded cropland soils may increase crop yield by 20 to 40 kilograms per hectare (kg/ha) for wheat, 10 to 20 kg/ha for maize, and 0.5 to 1 kg/ha for cowpeas. As well as enhancing food security, carbon sequestration has the potential to offset fossilfuel emissions by 0.4 to 1.2 gigatons of carbon per year, or 5 to 15% of the global fossil-fuel emissions.

/pdf/soil-carbon-sequestration-impacts-on-global-climate-change-1w7459lbbk.pdf

Soil carbon sequestration impacts on global climate change and food security.

Interactions between organisms are a major determinant of the distribution and abundance of species. Ecology textbooks (e.g., Ricklefs 1984, Krebs 1985, Begon et al. 1990) summarise these important interactions as intra- and interspecific competition for abiotic and biotic resources, predation, parasitism and mutualism. Conspicuously lacking from the list of key processes in most text books is the role that many organisms play in the creation, modification and maintenance of habitats. These activities do not involve direct trophic interactions between species, but they are nevertheless important and common. The ecological literature is rich in examples of habitat modification by organisms, some of which have been extensively studied (e.g. Thayer 1979, Naiman et al. 1988).

Organisms as ecosystem engineers

Indigenous groups offer alternative knowledge and perspectives based on their own locally developed practices of resource use. We surveyed the international literature to focus on the role of Traditional Ecological Knowledge in monitoring, responding to, and managing ecosystem processes and functions, with special attention to ecological resilience. Case studies revealed that there exists a diversity of local or traditional practices for ecosystem management. These include multiple species management, resource rotation, succession management, landscape patchiness management, and other ways of responding to and managing pulses and ecological surprises. Social mechanisms behind these traditional practices include a number of adaptations for the generation, accumulation, and transmission of knowledge; the use of local institutions to provide leaders/stewards and rules for social regulation; mechanisms for cultural internalization of traditional practices; and the development of appropriate world views and cultural values. Some traditional knowledge and management systems were characterized by the use of local ecological knowledge to interpret and respond to feedbacks from the environment to guide the direction of resource management. These traditional systems had certain similarities to adaptive management with its emphasis on feedback learning, and its treatment of uncertainty and unpredictability intrinsic to all ecosystems.

http://wildrodopi.org/data/documents/Rediscovery-Traditional-Ecological=20Knowledge.pdf

Rediscovery of traditional ecological knowledge as adaptive management

Understanding the negative and positive effects of agricultural land use for the conservation of biodiversity, and its relation to ecosystem services, needs a landscape perspective. Agriculture can contribute to the conservation of high-diversity systems, which may provide important ecosystem services such as pollination and biological control via complementarity and sampling effects. Land-use management is often focused on few species and local processes, but in dynamic, agricultural landscapes, only a diversity of insurance species may guarantee resilience (the capacity to reorganize after disturbance). Interacting species experience their surrounding landscape at different spatial scales, which influences trophic interactions. Structurally complex landscapes enhance local diversity in agroecosystems, which may compensate for local high-intensity management. Organisms with high-dispersal abilities appear to drive these biodiversity patterns and ecosystem services, because of their recolonization ability and larger resources experienced. Agri-environment schemes (incentives for farmers to benefit the environment) need to broaden their perspective and to take the different responses to schemes in simple (high impact) and complex (low impact) agricultural landscapes into account. In simple landscapes, local allocation of habitat is more important than in complex landscapes, which are in total at risk. However, little knowledge of the relative importance of local and landscape management for biodiversity and its relation to ecosystem services make reliable recommendations difficult.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1461-0248.2005.00782.x

Landscape perspectives on agricultural intensification and biodiversity – ecosystem service management

Dwarf mangroves on peat substrate growing in eastern Puerto Rico (Los Machos, Ceiba State Forest) were analyzed for element concentration, leaf sap osmolality, and isotopic signatures of C and N in leaves and substrate. Mangrove communities behind the fringe presented poor structural development with maximum height below 1.5 m, lacked a main stem, and produced horizontal stems from which rhizophores developed. This growth form departs from other dwarf mangrove sites in Belize, Panama, and Florida. The dwarf mangroves were not stressed by salinity but by the low P availability reflected in low P concentrations in adult and senescent leaves. Low P availability was associated with reduced remobilization of N and accumulation of K in senescent leaves, contrasting with the behavior of this cation in terrestrial plants. Remobilization of N and P before leaf abscission on a weight basis indicated complete resorption of these nutrients. On an area basis, resorption was complete for P but not for N. Sulfur accumulated markedly with leaf age, reaching values up to 400%, compared with relatively modest accumulation of Na (40%) in the same leaves. This suggests a more effective rejection of Na than sulfate at the root level. Dwarf mangrove leaves had more positive δ13C values, which were not related to salinity, but possibly to drought during the dry season due to reduced flooding, and/or reduced hydraulic conductance under P limitation. Negative leaf δ15N values were associated with low leaf P concentrations. Comparison with other R. mangle communities showed that P concentration in adult leaves below 13 mmol kg−1 is associated with negative δ15N values, whereas leaves with P concentrations above 30 mmol kg−1 in non-polluted environments had positive δ15N values.

https://www.fs.fed.us/global/iitf/pubs/ja_iitf_2010_medina001.pdf

Nutrient relations of dwarf Rhizophora mangle L. mangroves on peat in eastern Puerto Rico

Two maps depicting the forest resources of Peninsular Malaysia, one dated 1972 and the other 1982, were digitized into ARC/INFO for analysis of spatial and temporal trends. Estimates of 1972 and 1982 biomass density for each of 11 forest classes were also produced from inventory stand tables. These data allowed us to calculate changes in forest cover and biomass during the decade. Overall, forest area was reduced by 17%, and total biomass by 28%; however, this percentage varied among forest classes. For example, primary forest area declined by 23% while its biomass was reduced by 35%; disturbed forest area declined by 7% while its biomass was reduced by 19%. These data indicate that, in addition to loss of forest biomass because of changes in land use, biomass degradation was also occurring within the forests. Together, they represented a loss of 30 TgC/yr. Changes in perimeter area ratios were correlated with the degree of biomass degradation suggesting that the fragmentation of Malaysian forests, a process that increases their accessibility, was a cause of the degradation.

https://www.nrs.fs.fed.us/pubs/jrnl/1994/ne_1994_brown_001.pdf

Land-Use and Biomass Changes of Forests in Peninsular Malaysia from 1972 to 1982: A GIS Approach

https://www.fs.fed.us/global/iitf/pubs/RioPiedras_FNLrvsd.pdf

The Río Piedras watershed and its surrounding environment

https://www.fs.fed.us/global/iitf/pubs/ja_iitf_2005_frangi001.pdf

Nutrient cycling in Nothofagus pumilio forests along an altitudinal gradient in Tierra del Fuego, Argentina

Tropical forests are suffering from increasing intensities and frequency of disturbances. As a result, non-native species accidentally introduced or intentionally planted for farming, plantations, and ornamental purposes may spread and potentially invade undisturbed native forest. It is not known if these introduced species will become invasive, as a result of recurrent natural disturbances such as hurricanes. Using data from three censuses (spanning 15 years) of a 16-ha subtropical wet forest plot, we investigated the impact of two hurricanes on populations of plant species that were planted in farms and plantations that were then abandoned and from the natural spread of species introduced into Puerto Rico in the past. The populations of four species (Citrus paradis, Mangifera indica, Musa sp., and Simarouba glauca) changed little over time. Six species (Artocarpus altilis, Calophyllum calaba, Genipa americana, Hibiscus pernambucensis, Syzygium jambos, and Swietenia macrophylla) declined between the first two censuses after Hurricane Hugo, then increased again in Census 3 after Hurricane Georges. Spathodea campanulata gradually increased from census to census, while Coffea arabica declined. These introduced species represent only a small part of the forest basal area and few show signs of increasing over time. The number of stems per plant, new recruits, and the growth rates of these introduced species were within the ranges of those for native plant species. The mortality rates over both census intervals were significantly lower for introduced species (<5% year−1) than for native ones (15% year−1). Many new recruits established after Hurricane Hugo (prior to this study) had opened the forest canopy and these high mortality rates reflect their death as the canopy recovered. Only Swietenia macrophylla and Syzygium jambos showed an increase in stem numbers in the closed canopy area of forest that had suffered limited human disturbance in the past. A future increase in frequency of disturbance may enable greater stem numbers of introduced species to establish, while lower-mortality rates compared to native species, may allow them to persist during inter-hurricane intervals. An increase in the population of introduced species, especially for those that grow into large trees, may have an impact on this tropical forest in the future.

/pdf/land-use-history-hurricane-disturbance-and-the-fate-of-1s3xech6vp.pdf

Ariel E. Lugo

Papers

Nutrient relations of dwarf Rhizophora mangle L. mangroves on peat in eastern Puerto Rico

Land-Use and Biomass Changes of Forests in Peninsular Malaysia from 1972 to 1982: A GIS Approach

The Río Piedras watershed and its surrounding environment

Nutrient cycling in Nothofagus pumilio forests along an altitudinal gradient in Tierra del Fuego, Argentina

Land use history, hurricane disturbance, and the fate of introduced species in a subtropical wet forest in Puerto Rico