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.

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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

We review research on the species composition, structure, functioning, and response to disturbance of mahogany plantations in Puerto Rico. The review includes nine plantations at seven sites from dry to wet life zones, two soil parent materials (limestone and volcanic), three plantation designs (block, line, and taungya), and plantation ages from 18 to 64 years. Mahogany grew well regardless of plantation design or soil parent material but the species differed. Small-leaf mahogany grew better than big-leaf and the big-leaf × small-leaf hybrid mahogany in the dry life zone, on degraded sites, and on shallow limestone soils. Small-leaf mahogany failed to grow in moist to wet life zones. Big-leaf and hybrid mahogany had the fastest rates of growth and yield in moist life zones, regardless of soil parent material. All plantations were invaded by native tree species and increased in species richness and vertical stratification with age. All plantation species exhibited abundant regeneration under mature plantation canopies. More nutrients accumulated in vegetation and plantation litter than in vegetation and fine litter of paired secondary forests. Nutrient return to the forest floor was pulsed because of dry season peaks of leaf fall and mast fruit production by mahogany trees. Fruit production in both plantations and paired secondary forests influenced nutrient cycles by increasing nutrient return and accumulation on the forest floor, thereby decreasing within-stand nutrient use efficiency. Small-leaf mahogany had half the litterfall but more litter standing stock than did big-leaf or hybrid mahogany. Hurricane Hugo reduced tree biomass, opened the canopy, and created a pulse of mass and nutrient fall in paired plots of hybrid mahogany and a secondary forest stand. Six years after the hurricane, the plantation returned more nutrients to the forest floor than did the paired secondary forest but had a lower nutrient use efficiency and a similar nutrient turnover rate.

Structure and Dynamics of Mahogany Plantations in Puerto Rico

We studied the response of Prestoea montana (Sierra Palm, herefter Palm) brakes and a Palm floodplain forest to hurricanes in the Luquillo Experimental Forest in Puerto Rico. Over a span of 78 years, 3 hurricanes passed over the study sites for which we have 64 years of measurements for Palm brakes and 20 years for the Palm floodplain forest. For each stand, species composition, species density, basal area, tree density, rates of tree ingrowth and mortality, and importance value of tree species were assessed. We also estimated stand and Palm population aboveground biomass for the Palm floodplain forest. We found that different forest attributes such as basal area and tree density exhibited different temporal response patterns to hurricanes. The passing of 2 hurricanes in less than 10 years shifted the forest-response pattern of Palm brakes into a different trajectory with wider oscillations than before the 1989 hurricane. Neither Palm forest type reached steady state during the period of observation. Palm brakes spent about 50 of 64 years of the study in a transition state, and during the last 14 of those years, Cecropia schreberiana (Yagrumo) displaced the Palms as the species with the highest importance value, likely due to hurricane effects. The Palm floodplain forest remained in a transition mode over the 20-year span of the study. The results of the study showed that stands located on the leeward of hurricanes experienced less structural and species-composition changes and had more time to recover from hurricane effects than those exposed to the windward path of the hurricane. Caribbean Palm forests are dynamic systems whose structure, species composition, species density, and processes are finely coupled to frequency and intensity of hurricanes. Because Palm forest dynamics are closely tied to hurricanes, it is possible to anticipate that any future change in the frequency or intensity of hurricanes is likely to influence these forest attributes, including species ranking by importance value.

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Long-term response of Caribbean palm forests to hurricanes

Este ensayo aborda los problemas de conservacion que enfrentan los manglares en el Antropoceno, definido como la epoca de la dominacion humana sobre el mundo. En el repasamos las leyes, politicas, acuerdos internacionales y las acciones locales que se ocupan de la conservacion de los bosques de mangle en el Neotropico y se relacionan con el Antropoceno. La colaboracion entre gobiernos, organizaciones no gubernamentales y las comunidades que dependen de los manglares para su sustento sera decisiva en el Antropoceno. El ensayo tambien incluye comentarios sobre los avances recientes en ecologia de manglares y en ecofisiologia que explican como los manglares podrian responder a los cambios de temperatura y precipitacion, el aumento del nivel del mar y otras perturbaciones naturales y antropogenicas. Los manglares en el Antropoceno tambien enfrentaran a cambios en su composicion de especies, dado el actual movimiento de especies de manglares a traves de barreras continentales como resultado de la actividad humana. Estas tendencias conduciran a nuevas formaciones de manglares y en algunos casos ampliaran la presencia de los manglares en todo el mundo. La solucion a la persistencia de manglares en el Antropoceno es no aislar a los manglares de la gente, sino regular las interacciones entre los manglares y los seres humanos a traves de una gestion eficaz. Tambien tendremos que ampliar el alcance del analisis ecologico de los ecosistemas de manglar para incluir las fuerzas sociales convergentes en los manglares a traves de un enfoque analitico que se ha denominado Ecologia Social

/pdf/desafios-de-la-conservacion-del-mangle-en-el-antropoceno-10qdzwfc0o.pdf

Desafíos de la conservación del mangle en el Antropoceno

The article presents comparative data for aboveground biomass, wood volume, nutrient stocks (N, P, K) and leaf litter in different types of forests in Puerto Rico The aim of the study is to assess how novel forests of Castilla elastic, Panama Rubber Tree, and Spathodea campanu lata , African Tulip Tree, compare with tree plantations and native historical forests (both secondary and mature) It found that novel forests of these two species can accumulate large quantities of biomass and nutrients above ground that they do so at a rapid rate and that they exhibit high rates of leaf fall They can match or exceed tree plantations and native forests in all parameters except the accumulation of nitrogen above ground These results support the notion that novel forests can contribute to the restoration of biomass and nutrient stocks in previously deforested sites However, across the island as a whole, the values for biomass in many types of novel forest are lower than those observed for Spathodea and Castilla in this study The age of stands and site conditions appear to be critical to the level of nutrient and biomass accumulation in these forests

/pdf/biomasse-aerienne-volume-de-bois-stocks-de-nutriments-et-3asjq7ot8i.pdf

Biomasse aérienne, volume de bois, stocks de nutriments et litière de feuilles au sein de nouvelles forêts, mis en comparaison avec des forêts naturelles et des plantations à Puerto Rico

Ariel E. Lugo

Papers

Structure and Dynamics of Mahogany Plantations in Puerto Rico

Long-term response of Caribbean palm forests to hurricanes

Desafíos de la conservación del mangle en el Antropoceno

Biomasse aérienne, volume de bois, stocks de nutriments et litière de feuilles au sein de nouvelles forêts, mis en comparaison avec des forêts naturelles et des plantations à Puerto Rico

When and Where Biota Matter