Elvia Melendez-Ackerman

University of Puerto Rico at Rio Piedras | UPR-RP · Department of Environmental Science

INSECT VISITORS ON THE FLOWERS OF FOUR CULTIVARS OF MANGIFERA INDICA AT THE AGRICULTURAL EXPERIMENT SUBSTATION OF JUANA DIAZ, PUERTO RICO

Addressing urban forest management and governance challenges is fundamental for implementing urban forest policies. Most of the evidence on this topic comes from Global North cities, so little is known about how urban forest management and governance are experienced by urban forest actors in Global South cities, including Latin American and the Car...

Germplasm in the form of living collections can make important contributions to the understanding of how processes that occur at the pollination stage influence reproduction and plant yields. Using artificial pollination experiments this study evaluated the degree of self-compatibility, dependence of their reproductive systems on flower visitors to...

Insular pollination systems are more extinction-prone and vulnerable to invasive species than mainland ones. They often have plants with reproductive mechanisms allowing for self-compatibility and low species-rich communities of pollinators. Here, we document different reproductive traits of the tropical tree Guaiacum sanctum on two insular populat...

Urban forests are valuable spaces for species conservation, protection of local biodiversity and provision of ecosystem services. However, they are also vulnerable to the impact of extreme climate events like hurricanes. Understanding how urban forests are responding to hurricane disturbances is crucial to improve their design, management, and resi...

Sustainable forestry is key to increase the adaptive capacity and resilience of regions exposed to extreme atmospheric events. Understanding social acceptability of forest management practices through a public dialogue that involves a diversity of stakeholders is important to define management policies and strategies. Here, we inquire about social...

In 2016, the US Congress enacted the Puerto Rico Oversight, Management, and Economic Stability Act (PROMESA), which led to a federally appointed Financial Oversight and Management Board (FOMB) to oversee restructuring of the island's $74 billion debt and achieve sustainable budgets. Many economists argue that even debt adjustment, which was approve...

Maintaining a diverse urban forest that provides ecosystem services can promote urban sustainability and resilience to environmental change. Around the world, cities have taken to inventorying their urban trees and quantifying their ecosystem services but more so in industrialized counties than in Latin America. Here we describe the results of an i...

Fine-resolution satellite imagery is needed for characterizing dry season phenology in tropical forests since many tropical forests are very spatially heterogeneous due to their diverse species and environmental background. However, fine-resolution satellite imagery, such as Landsat, has a 16-day revisit cycle that makes it hard to obtain a high-qu...

Urban forests are valuable spaces for species conservation, protection of local biodiversity and provision of ecosystem services. However, they are also vulnerable to the impact of extreme climate events like hurricanes. Understanding how urban forests are responding to hurricane disturbances is crucial to improve their design, management, and resi...

Puerto Rico experienced the most prolonged power outage in US history after two hurricanes hit the Archipelago in September 2017. Hurricane Irma left over one million people without electricity, and Hurricane Maria left Puerto Rico in a total blackout when it hit. The damages to 80 percent of the electrical grid opened the possibility to the Puerto...

The ability to predict growth and potential yield is essential for planning forest management. Here we developed a narrow size-class diameter model to simulate growth in a mature plantation (age 42 years) of big-leaf mahogany (Swietenia macrophylla King) in a subtropical moist forest in Puerto Rico. We calculated optimal rotation age by means of th...

Mangifera indica is a widespread economically important tropical fruit. An ongoing study at the Juana Diaz Experimental Station in Puerto Rico aims to understand the factors that influence local pollination success and fruit yields in four fields each hosting a different mango cultivar (Keitt, Kent, Tommy Atkins, and Julie) at different temporal sc...

Worldwide the number of non-native species escaping from cultivation into native habitats is steadily increasing with no signs of saturation. Species that eventually become invasive may generate unwanted social and ecological conditions especially in areas of conservation concern. This study built upon prior biodiversity work from 432 residential y...

The Caribbean was recently struck by two hurricanes (Irma and María) considered among the most powerful since 1928 in that region. !ese hurricanes brought intense and continuous rainfall, which likely impacted plants inhabiting riparian areas through flash floods and landslides. We conducted a post-hurricane assessment of Gesneria pauci!ora, an end...

The long‐term fate of populations experiencing disequilibrium conditions with their environment will ultimately depend on how local colonization and extinction dynamics respond to abiotic conditions (e.g. temperature and rainfall), dispersal limitation and biotic interactions (e.g. competition, facilitation or interactions with natural enemies). Un...

Residential green spaces are increasingly gaining attention for their potential to contribute to ecosystem services of social and ecological value for cities. This research evaluated the potential of residential yards of San Juan, Puerto Rico, to contribute to urban sustainability through the provision of ecosystem services using a social-ecologica...

Attitudes toward urban residential trees and awareness of their ecosystem services and disservices may play an important role in management decisions of private residential green spaces with important consequences to urban sustainability. In 2011, 397 household surveys were conducted in six locations of the Río Piedras Watershed (San Juan, Puerto R...

As a result of climate change, both cyclonic storms (e.g., hurricanes) and droughts are increasing in severity and frequency around the globe. Additionally, sea level is rising. This poses a particular challenge for island communities. This case study looks at Puerto Rico, a U.S. territory located in the Caribbean. Puerto Rico was struck by two hur...

The offshore cays around the main islands of Puerto Rico, St. Thomas, St. John, and St. Croix are largely uninhabited and provide habitat for threatened, endangered, at-risk, and species of greatest conservation need including many resident and migratory species of seabirds, shorebirds, endemic reptiles, and plants. Management is limited by insuffi...

Heliconia bihai is a highly polymorphic species. Populations of the species are distributed throughout the Lesser Antilles and northern South America; the most obvious sign of polymorphism is manifested through differences in bract color. This variation has been attributed to pollinator-mediated selection, but other processes are also plausible. To...

Premise: Gesneria pauciflora is a rare, threatened plant in riparian forests. Periodic disturbances, expected in this habitat, could influence demographic dynamics on plant populations, yet their impact may not be the same across the watershed. We hypothesized that differences in disturbances between the main channel and tributaries may lead to sp...

Despite increasing attention to the role that multiple sets of knowledge, including citizen-based knowledge, have in developing more resilient and sustainable pathways for flood management, informal knowledge systems have yet to gain legitimacy and be integrated into formal planning and decision-making process. Here we show that a knowledge systems...

Rainfall interception is an important part of the urban hydrological cycle. Understanding is limited about the role of urban trees and other vegetation in the interception process. This study quantified interception losses by six trees in the Caribbean coastal city of San Juan, Puerto Rico, three representing a broadleaf evergreen, and three repres...

Rapid assessments of the change in ecosystem services derived from coarse woody vegetation were performed for three municipalities (San Juan, Ponce, Mayagüez) in the island of Puerto Rico following Hurricanes Irma and Maria. The assessments used two approaches (fine-scale and landscape-level) using computer models within the suite of i-Tree tools (...

Numerous studies have highlighted the significance of the mite genus Brevi- palpus (Acari: Tenuipalpidae), which has risen from virtual obscurity to that of economic importance over the last few decades. There are 3 Brevipalpus mite species known to colonize a substantial number of fruit crops and infect them with deadly viruses; it has been shown...

Aim: Seasonally dry tropical forest (SDTF) of the Caribbean Islands (primarily West Indies) is floristically distinct from Neotropical SDTF in Central and South America. We evaluate whether tree species composition was associated with climatic gradients or geographical distance. Turnover (dissimilarity) in species composition of different islands o...

School vegetable gardens provide environmental services and social benefits that can have a wide impact in communities and cities, while preparing future generations for more sustainable ways of living. For a school to create and sustain a vegetable garden, both social and physical environment (soils) must be favorable. We evaluated 20 elementary s...

Aim Seasonally dry tropical forest ( SDTF ) of the Caribbean Islands (primarily West Indies) is floristically distinct from Neotropical SDTF in Central and South America. We evaluate whether tree species composition was associated with climatic gradients or geographical distance. Turnover (dissimilarity) in species composition of different islands...

Tropical dry forests on calcareous substrate constitute the main vegetation cover in many islands of the Caribbean. Dry climate and nutrient scarcity in those environments are ideal to investigate the potential role of high levels of soil calcium (Ca) in regulating plant selection and productivity. We analyzed the elemental composition of soil, loo...

Residential green areas often represent a significant portion of a city’s green infrastructure which has generated great interest in studying the factors that contribute to the formation of plant associations in residential yards. This project evaluated the external factors to the household social-ecological system that influence the availability o...

Urban sustainability discourse promotes the increased use of green infrastructure (GI) because of its contribution of important ecosystem services to city dwellers. Under this vision, all urban green spaces, including those at the household scale, are valued for their potential contributions to a city's social-ecological functioning and associated...

The negative impact of invasive plants on native species has been well documented, but little is known about the specific role that invaders play on the population decline of native species. Here we used demographic models to evaluate how the alien grass Megathyrsus maximus affects the population dynamics of the native cactus Harrisia portoricensis...

Abstract - Mona Island protects one of the most important remnants of Caribbean dry forests and hosts a high diversity of rare and endangered plant and animal species. Feral ungulates (goats and pigs) were introduced to the island ~500 y ago, and their populations may be threatening the conservation of Mona Island’s native biodiversity. In this stu...

Abstract - Soil–vegetation associations have been understudied in tropical dry forests when compared to the amount of extant research on this issue in tropical wet forests. Recent studies assert that vegetation in tropical dry forests is highly heterogeneous and that soil variability may be a contributing factor. In this study, we evaluated the rel...

The complexity of solving environmental problems has led to the development of new programs focused on interdisciplinary research and education to develop professionals capable of integrating different kinds of information. The loss of biodiversity in the tropics is one of those complex issues that involves numerous stakeholders, particularly in th...

Planting tree species with desirable traits may catalyze forest regeneration in increasingly common degraded lands by restoring soil properties and attracting seed dispersers. We sampled forest regenera-tion in an experimental plantation of Albizia lebbek, an introduced N-fixing species, on a degraded pasture in northern Puerto Rico, 27 years after...

Movement has broad implications for many areas of biology, including evolution, community and population ecology. Movement is crucial in metapopulation ecology because it facilitates colonization and reduces the likelihood of local extinction via rescue effects. Most metapopulation modeling approaches describe connectivity using pair-wise Euclidean...

Flood-prone communities are especially susceptible to increasing flooding frequency due to climate change. Adaptive capacity is one of the main components in determining vulnerability of a susceptible community. But in order to implement efforts that might increase adaptive capacity, awareness and knowledge of objective risk to natural hazards are...

Green spaces within residential areas provide important contributions to the sustainability of urban systems. Therefore, studying the characteristics of these areas has become a research priority in cities worldwide. This project evaluated various aspects of the plant biodiversity of residential yards (i.e., front yards and back yards within the Ri...

A growing body of work has emphasized the importance of residential areas to the overall green infrastructure of cities and recognizes that outcomes related to these areas are best studied using a social-ecological approach. We conducted vegetation surveys to evaluate yard practices that relate to the state of the yard vegetation, including species...

This paper presents initial efforts to establish the San Juan Urban Long-Term Research Area Exploratory (ULTRA-Ex), a long-term program aimed at developing transdisciplinary social-ecological system (SES) research to address vulnerability and sustainability for the municipality of San Juan. Transdisciplinary approaches involve the collaborations be...

This paper presents initial efforts to establish the San Juan Urban Long-Term Research Area Exploratory (ULTRA-Ex), a long-term program aimed at developing transdisciplinary social-ecological system (SES) research to address vulnerability and sustainability for the municipality of San Juan. Transdisciplinary approaches involve the collaborations be...

Background/Question/Methods Urban residential areas provide opportunities for the provision of localized key ecosystem services (ES). In order to improve strategies for green infrastructure management, resident’s preferences and attitudes towards ES need to be considered. Humans have direct (and indirect) impact on socio-ecological characteristics...

Background/Question/Methods Urban residential green areas afford multiple ecological, economic, and social benefits, yet in tropical urban environments green infrastructure remains understudied regarding its potential to provide future environmental services, in part because of a lack of data concerning management preferences. In heavily urbanize...

The metapopulation concept is widely established in population biology. It predicts that the likelihood of colonization of an empty patch is positively correlated with its connectivity, because colonizers from occupied patches will be more likely to reach an empty patch if they are closer to it. Another prediction is that the likelihood of extincti...

Question Hurricanes are a major factor influencing forest structure and have been linked to higher incidences of multiple‐stemmed trees in Caribbean dry forests relative to the continent. In Sept 1998, category 3 Hurricane Georges passed over Mona Island. This island, unlike others in the Caribbean, has had feral goats for five centuries. In this s...

Mona Island is the third largest island in the archipelago of Puerto Rico located about 70 km west of the main island. Presently it is a wilderness refuge that contains well-preserved arboreal and shrubby vegetation, and distinct cactus forests, covering the calcareous, elevated plateau. During a forest inventory conducted by the US Forest Service,...

Mona Island is the third largest island in the archipelago of Puerto Rico located about 70 km west of the main island. Presently it is a wilderness refuge that contains well-preserved arboreal and shrubby vegetation, and distinct cactus forests, covering the calcareous, elevated plateau. During a forest inventory conducted by the US Forest Service,...

Nectar robbers may have direct and indirect effects on plant reproductive success but the presence of nectar robbing is not proof of negative fitness effects. We combined census data and field experiments to disentangle the complex effects of nectar robbing on nectar production rates, pollinator behavior, pollen export, and female reproductive succ...

Harrisia portoricensis is an endemic Caribbean cactus currently under threatened status. In this study we used population projection matrices to evaluate the conservation status of this species and we performed a systematic analysis of the effects of matrix dimensionality on the inferred demographic parameters. Results revealed that population grow...

Aims The spatial distribution of biotic and abiotic factors may play a dominant role in determining the distribution and abundance of plants in arid and semiarid environments. In this study, we evaluated how spatial patterns of microhabitat variables and the degree of spatial dependence of these variables influence the distribution and abundance of...

Harrisia portoricensis is a threatened columnar cactus whose distribution range is currently restricted to three small islands of the Puerto Rican Bank: Mona, Monito, and Desecheo. In this work we present a brief summary of results on natural history and population size estimates of H. portoricensis populations, extracted from two years of populati...

The distribution of orchids in the epiphytic or lithophytic environment is likely to result from the interactions with other plant species. We tested for associations between bryophyte cover and diversity and the densities of different demographic stages (seedlings and juveniles vs adults) of Lepanthes rupestris (Rock Babyboot Orchid), a riparian t...