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Life Sciences Commons

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Ecology and Evolutionary Biology

SIT Graduate Institute/SIT Study Abroad

2022

Articles 1 - 7 of 7

Full-Text Articles in Life Sciences

Orb-Weaver Diversity And Niche Partitioning In Ecuador’S Amazonian Foothills: What Spiders Can Reveal About Tree Fall Gaps, Streams, And Cultivated Areas, Riley Endries Oct 2022

Orb-Weaver Diversity And Niche Partitioning In Ecuador’S Amazonian Foothills: What Spiders Can Reveal About Tree Fall Gaps, Streams, And Cultivated Areas, Riley Endries

Independent Study Project (ISP) Collection

As abundant predators at the top of arthropod food chains, spiders are excellent bioindicators. Araneae is a megadiverse and extremely understudied order, especially in the tropics. This study aims to investigate the diversity of orb-weaver spiders across a disturbance gradient and variety of habitat types as well as their microhabitat preferences and potential niche partitioning. Spider collection was performed on spiders of the families Araneidae, Tetragnathidae, and Theridiosomatidae in Sumak Kawsay in Situ biological reserve in the lower elevation cloud forest of Ecuador’s Andean foothills. Spiders and webs were observed and analyzed from primary and secondary forest tree fall gaps, …


Afforestation And Biodiversity: Bryophyte Richness Changes Between Icelandic Forest Types, Kian Mcdonough Oct 2022

Afforestation And Biodiversity: Bryophyte Richness Changes Between Icelandic Forest Types, Kian Mcdonough

Independent Study Project (ISP) Collection

Forest-dwelling bryophytes (mosses, liverworts, hornworts) greatly contribute to biodiversity and ecosystem function but are largely under-studied in comparison to vascular plants. With Iceland’s large-scale afforestation efforts there is a need to understand how different afforestation species are affecting biodiversity, including bryophyte diversity. This study looked at differences in ground-floor bryophyte richness across Sitka spruce, lodgepole pine, and downy birch forests and found that bryophyte richness was highest in the Sitka spruce forests and lowest in downy birch forests. While this suggests a negative correlation between bryophyte richness and light availability, since the conifer species have the densest copy cover, other …


The Nesting Behavior Of Russet-Backed Oropendola On Sumak Allpa, Ecuador: An Analysis Of Nest Construction And Interactions With Competing Species, Claire Molina Oct 2022

The Nesting Behavior Of Russet-Backed Oropendola On Sumak Allpa, Ecuador: An Analysis Of Nest Construction And Interactions With Competing Species, Claire Molina

Independent Study Project (ISP) Collection

Nests are the literal place of birth of bird species; they are incredibly important in the survival and reproduction of populations. Therefore, nesting behavior is a gateway into the lives and success of the animals. With the degradation of natural landscapes due to human activity, there is more of a need to monitor these nests to ensure healthy inhabitants. The Russet-backed Oropendola (Psarocolius angustifrons) creates unique, pendulous nests that are subject to piracy, parasitism, and predation; as well as weather phenomenon’s such as wind and rainstorms. This study describes the nest construction behavior, nest materials and nest architecture by collecting …


Observational Study Of Woolly Monkey Behavior And Vocalizations: Behavioral Time Allotment And Vocalization Habits Of A Small Population Of Poeppig’S Woolly Monkey (Lagothrix Lagotricha Poeppigii) In The Ecuadorian Amazon, Marina Smith-Hanke Oct 2022

Observational Study Of Woolly Monkey Behavior And Vocalizations: Behavioral Time Allotment And Vocalization Habits Of A Small Population Of Poeppig’S Woolly Monkey (Lagothrix Lagotricha Poeppigii) In The Ecuadorian Amazon, Marina Smith-Hanke

Independent Study Project (ISP) Collection

Poeppig’s woolly monkey (Lagothrix lagotricha poeppigii), a species of primate native to the Amazonian regions of western Brazil, eastern Ecuador, and northeastern Peru, is classified as endangered by the IUCN. These large, frugivorous primates are threatened by habitat loss and climate change as a result of human interference. Deforestation, hunting, petroleum mining, and illegal trafficking are all huge threats to this species. As a result of these pressures, their populations have decreased by at least 30% over the past three generations. However, as keystone seed dispersers, they are essential for Amazonian ecosystem health; without their seed dispersal services, a loss …


Investigating Primary Succession Following The Retreat Of The Breiðamerkurjökull Glacier, Iceland, Ella Roelofs Oct 2022

Investigating Primary Succession Following The Retreat Of The Breiðamerkurjökull Glacier, Iceland, Ella Roelofs

Independent Study Project (ISP) Collection

The accelerating rates of glacier retreat around the world as a result of climate change make the study of primary succession in expanding forefields increasingly important. While this is a well studied topic in many parts of the world, little data exists specific to Iceland. This study investigated vegetation development along a chronosequence of eight time periods in the Breiðamerkurjökull outwash plain. Data was collected on percent vegetation cover, dominant species, the number of unique plant groups, and percent cover of five substrate types at 10 plots (0.55 x 0.55 m quadrats) per time period. Important findings include the fact …


Arthropod Assemblages At The Intersection Of Epiphyte And Soil Habitats: An Assessment Of Understory Level Nonvascular Epiphyte Communities And Their Connectivity Within A Tropical Montane Rainforest, David “Max” Jones Oct 2022

Arthropod Assemblages At The Intersection Of Epiphyte And Soil Habitats: An Assessment Of Understory Level Nonvascular Epiphyte Communities And Their Connectivity Within A Tropical Montane Rainforest, David “Max” Jones

Independent Study Project (ISP) Collection

Canopy arthropods communities represent a disproportionate amount of global species richness (Stuntz 2001). Understanding arthropod composition and connectivity of lower epiphyte communities is important in understanding how canopy arthropods communities are formed and will respond to change (Floren and Linsenmair 1998). As such this study examined arthropod assemblages living within nonvascular epiphyte communities (epiphyte mats) living directly upon lower trunk regions of 24 trees in a tropical montane rain forest within the Santa Lucia Nature Reserve in Pichincha, Ecuador. Trees were assessed for size, epiphyte diversity, and epiphyte coverage before arthropod sampling within the epiphyte mats. Soil assessments were taken …


The Relationship Between Substrate Composition, Community Structure And Feeding Preferences Of Parrot Fishes (Scaridae) In Anmardub, Guna Yala Coastal Reefs, Caitlin Amman Apr 2022

The Relationship Between Substrate Composition, Community Structure And Feeding Preferences Of Parrot Fishes (Scaridae) In Anmardub, Guna Yala Coastal Reefs, Caitlin Amman

Independent Study Project (ISP) Collection

Coral reefs are important marine ecosystems, as they support biodiversity and generate buffer zones, yet their abundance is incredibly limited globally. One of the main threats that coral reefs face is excessive macroalgal coverage, which limits sunlight from reaching corals, and thus, limits the energy that can reach them. Parrot fish (Scaridae) are keystone herbivores, as they consume macroalgae growing on corals, which aids in reef survivability. While there is previous research on the abundances, sizes, and feeding habits of Scaridae species in the Caribbean, there is no published research on how community structure and feeding preferences of parrot fishes …