The Cape (CFR) is an exceptional centre plant This diversity is concentrated in a profusion geographically restricted endemic species within a The CFR is a rich and dynamic for the molecular study of speciation, but until recently studies have focused on factors influencing diversification of whole lineages, than on details the speciation process within and between species pairs.

Globally we are experiencing a biodiversity crisis and potentially a sixth mass extinction event. Plant specimens are one of the best, most concrete records of biodiversity that we can create. Despite this, the rate of plant collecting has declined steeply since World War II. Now more than ever, plant collections are vital, both for the purpose of quantifying the plant biodiversity in an area and for discovering previously unrecognized diversity. In Chapter 1, we conducted a floristic survey of the Cal Poly Swanton Pacific Ranch. The Swanton Pacific Ranch (SPR) is located north of the small town of Davenport California, in Santa Cruz county. SPR is 3,200 acres and contains areas of salt marsh, coastal bluff, coastal prairie, riparian forest, redwood forest, mixed conifer forest and chaparral in approximate ascending order of elevation. The property extends over an elevational gradient from 0 m to 420 m (1400 ft). We documented 634 taxa at SPR. In total, 974 specimens were collected during this project, 405 specimens in 2017 and 569 in 2019. We reviewed 211 historic specimens. We vouchered 546 taxa between 2017 and 2019 and observed but did not collect 6 taxa. 53 taxa are represented from historic collections and were not relocated. There are 30 taxa listed as historically present from personal observations of the authors but without vouchers. Though these do not have the same value as a physical specimen, we believe that all information is valuable and have included them with a clear indication of the source of the record. There were 465 native and 169 non-native taxa documented in the study area. There were 93 families represented, with Asteraceae, Poaceae and Fabaceae be ing the top three most speciose respectively. There were 83 taxa noted as locally rare following Neubauer, of these 16 taxa have a California Native Plant Society (CNPS) rare plant rank. We vouchered one new taxon for Santa Cruz County, Senecio aphanactis, which has a CNPS rare plant rank of 2B.2 In Chapter 2, we describe a new combination in the Sanicula crassicaulis species complex. During the project detailed in Chapter 1, we observed and collected several specimens that keyed to Sanicula crassicaulis Poepp. ex. D.C. but were notably distinct from other S. crassicaulis that we collected in the area. On further investigation, we found that these plants match the type specimen of S. nudicaulis Hook & Arn., described in 1839 and later synonymized with S. crassicaulis. This taxon is distinguished primarily by its long, sinuate marginal leaf trichomes, in contrast to the short, straight marginal trichomes of S. crassicaulis. Additionally, the length of the most proximal prickles on the schizocarps is about the same as the length of the most distal rather than the distal prickles being much longer as in S. crassicaulis and the angle of attachment of the prickles is more or less perpendicular as opposed to acute in S. crassicaulis. The known range of this taxon is between the San Francisco Bay Area and Santa Barbara County, generally near the coast. Here we recognize this taxon as a variety in S. crassicaulis, Sanicula crassicaulis var. nudicaulis. We provide a diagnosis, a map of the known range of the taxon and a key to the varieties of S. crassicaulis. Overall this project has significantly increased or knowledge and documentation of the flora of both SPR and Santa Cruz county. In addition to the immediate benefits of this study (a complete species list for SPR, the discovery of a new taxon, and the mapping of all rare species at SPR) we have also contributed almost 1,000 physical specimens to the Cal Poly Hoover herbarium which may be used in future taxonomic and ecological studies.

Collisions with human-made structures are responsible for billions of bird deaths each year, resulting in ecological damage as well as regulatory and financial burdens to many industries. Acoustic warning signals can alert birds to obstacles in their flight paths in order to mitigate collisions, but these signals should be tailored to the sensory ecology of birds in flight. The effectiveness of various acoustic warning signals likely depends on the influence of background noise and the relative ability of various sound types to propagate within a landscape. I evaluated the ability of four sound signals to elicit collision-avoidant flight behaviors from birds released into a flight corridor containing a physical obstacle. I selected signals to test two frequency ranges (4-6 kHz or 6-8 kHz) and two temporal modulation patterns (broadband or frequency-modulated oscillating) to determine whether any particular combination of sound attributes elicited the strongest collision avoidance behaviors. I found that, relative to control flights, all sound treatments caused birds to maintain a greater distance from hazards and to adjust their flight trajectories before coming close to obstacles. There were no statistical differences among different sound treatments, but consistent trends within the data could suggest that the 4-6 kHz frequency-modulated oscillating signal elicited the strongest avoidance behaviors, followed by the 6-8 kHz broadband signal. I conclude that acoustic warning signals could be an effective avian collision deterrent in several contexts, and that the particular sound used in a warning signal may impact the detectability of the signal as well as the type of flight behaviors used to evade a collision. These findings can be used to design more effective warning signals and demonstrate the value of using behavioral data to assess collision risk.

With species increasingly becoming imperiled due to anthropogenic activities, conservation practitioners are tasked with determining conservation priorities in order to make the best use of limited resources. The United States’ Endangered Species Act (ESA) has two listing statuses into which imperiled species are placed to receive protections: Threatened or Endangered. In the first chapter, our objective was to identify differences between Threatened and Endangered species beyond what is outlined in their ESA definitions. To our knowledge, this is the first study to compare listing status for species protected by the ESA on the basis of types and number of threats they face. For six broad-scale threats (habitat modification, overutilization, pollution, species-species interactions, environmental stochasticity, and demographic stochasticity), we investigated whether there is a difference in the number and types of threats which impact Threatened and Endangered species at the time of their listing. We found that Threatened (X̄ = 2.9, SD = 1.4) and Endangered (X̄ = 3.0, SD = 1.1) species were faced by a similar number of threats at their time of their listing. The only broad-scale threat that disproportionately impacted Endangered species more than Threatened species was demographic stochasticity; Endangered species were 1.9 times (95% CI = 1.4 -2.7) more likely to have this threat than Threatened species. We found four finer-scale demographic stochasticity threats (few individuals in one population, few individuals in multiple populations, lack of reproduction, and genetic loss) to be strong predictors of Endangered status. The similarities in the number and types of broad-scale threats faced by Threatened and Endangered species suggest that changes recently made to the ESA may be detrimental to the recovery efforts of future Threatened species. In the second chapter, our objective was to identify temporal trends in threats facing the four major phyla protected by the United States Endangered Species Act: angiosperms, arthropods, mollusks, and vertebrates. For 24 threat types, we created models to determine whether there was a linear, quadratic, or pseudo-threshold association between year and the probability that a phylum was listed with a given threat. We were able to identify temporal trends for 79% of the 96 possible threat-phylum combinations. We found that angiosperms had the highest peak probability of being listed with the greatest number of threats (N = 10), followed by mollusks (N = 8) and more distantly by arthropods (N = 4) and vertebrates (N = 2). We found that vertebrates had the greatest number of threats (N = 16) for which the year with their greatest probability of their being listed with a threat was their most recent year of listing. The other three phyla were similar to each other for this metric, mollusks having 12 and angiosperms and arthropods each having 11 threats peak in their most recent year of listing. We only identified one threat/phylum combination for which the maximum probability of their being listed with a threat was in their first year of listing (i.e., the threat has been consistently decreasing): authorized take impacting angiosperms. Overall, we believe our findings can be used to assist conservation efforts by identifying which threats have been decreasing or stable over time and which have been increasing that are in need of more attention.

The Cape (CFR) is an exceptional centre plant This diversity is concentrated in a profusion geographically restricted endemic species within a The CFR is a rich and dynamic for the molecular study of speciation, but until recently studies have focused on factors influencing diversification of whole lineages, than on details the speciation process within and between species pairs.

The Response of mobile intertidal invertebrates to subsistence harvesting in Northern KwaZulu Natal was investigated. Spatial scale comparisons were made between as well as within harvested and non-harvested locations. The difference in three population variables was investigated: i) abundance of species groups. ii) size structure of each organism and iii) community structure of mobile organisms. Abundance analysis revealed no significant difference between harvested and no harvested regimes for most species' groups, excepting Snails and Chitons. Snails were more abundant und chitons less abundant at harvested sites. A significant difference.... between locations was however noted, for all species groups, suggesting that variation in abundance within is more prominent than between harvesting regimes. Size stmcturc analysis revealed significantly larger sizes for most spec1cs at non harvested locations, with only Morula gm1111/u111 and Scutellastm exusw showing u significantly larger size structure at non-harvested locations. Community structure analysis revealed no clear distinction between or wi1hin harvested locations. A decrease in size structure with no co1Tespondi11g density effect may be a function of the preference of harvesters for larger individuals, thereby favouringjuveaile populations. The possibility also exists that density effects have been masked due to the use of size instead of biomass data. Converting to size data to biomass, using wet mass versus size regressions, may be a more appropriate analysis method. The observed differences in community structure between as well ru; within loi:-ations indicates that the intertidal communities are inl1erintly hcterogenous in this area. ln order 10 determine the irnpacr of exploitation. spatial scale comparisons between harvesting regimes thus ideall y need to be conducted to each location. [n this study there was also a lack of representative control sites, us unharvested locatio11s are impacted by fisherman and tourists. A possible strategy would be to demarcate "110-go" areas in harvested and non-harvested areas, to serve as both controls and provide broodi11g stocks for adjacent ledges. It is however recommended that more research emphasis be placed on U1e user in evaluating the effects ofhurmtn tmpact on intertidal resource.

Hypodontium is a moss genus currently comprising two species, H. dregei and H. pomiforme, endemic to Southern Africa, occurring in Zimbabwe and the eastern and southern parts of the Flora of Southern Africa areas. lt was originally assigned to the family Calymperaceae but was recently moved to Pottiaceae. The two families do not differ absolutely and Hypodontium possesses combinations of characters that could place it in either. This study used molecular DNA sequence data from two chloroplast gene regions, tmLtmF and rps4, to investigate the family status of the genus. The results obtained showed that it is not a member of either Calymperaceae or Pottiaceae, and supports the erection of a new family to accommodate Hypodontium. Hypodontium pomiforme occurs as two distinct morphological forms, and it has been suggested that these two forms might constitute two separate species. This study used both morphological (cluster analysis and Canonical Discriminant Functions Analysis) and molecular (nuclear ITS sequences) data to test this hypothesis. Results of both methods support the idea of significant difference between the two forms. Three species are therefore proposed for the genus Hypodontium, with H. humilopapillosum Manyanga & Hedderson described as new. A key is provided for the three species along with brief descriptions and a distribution map for each.

Climate change has caused gradual changes within marine environments within the last couple decades and is expected to continue to impact these ecosystems. Changes to these ecosystems are anticipated to emerge as adverse effects reach the lowest and highest levels within trophic food webs. For example, these environmental changes may change the abundance and distribution of species within their current geographic range. In extreme cases, climate change has already resulted in range shifts of terrestrial and marine species. A need for bioindicator species has emerged, so that they may be used to indicate when climate change may impact marine communities and whether these communities are at risk. Bioindicators are useful in that they can be early indicators for adverse effects and be used to indicate to decision-makers that intervention is needed before adverse effects can spread to the rest of a particular ecosystem. Bioindicators that are responsive to environmental changes are ideal for use. Mytilus edulis (blue mussels) and Donax variabilis (coquina clams) are two species that could potentially have use as bioindicators for climate change. However, it is not known how responsive the physiological condition of these species is to environmental changes. Our thesis objectives were to determine whether differences in the physiological condition and recruitment rate of blue mussels and coquina clams on the Eastern Shore are connected to seasonal water quality changes in the northern hemisphere Spring-Summer months and (2) to determine whether there have been long-term (9 years) changes in mussel and clam physiology and interpret these changes in the context of climate change. We found some evidence for a connection between blue mussel and coquina clam physiology and recruitment and seasonal changes in water quality on the Eastern Shore. We also found that blue mussel and coquina clam physiology did exhibit long-term spatiotemporal changes through time on Virginia’s Barrier Islands. Blue mussels showed an early indication of a possible range shift to come. On southern barrier islands, blue mussels either had lower physiological condition and recruit counts or had higher rates of decline in these metrics. Coquina clams on the other hand, only showed evidence of declines in their physiological condition at Hog Island. This could be an early sign of the sublethal impacts stemming from gradual environmental changes and may signal that blue mussels and coquina clams will continue to decline in quality and quantity in these areas of Virginia’s Eastern Shore. Declines in blue mussel quality and quantity could be worrisome as they not only provide several economic and ecological services that benefit humans, but also are an important food source for the migrating shorebird species that use Virginia Barrier Islands as a refueling station. While worrisome, this response in blue mussels does indicate that this species may be responsive to environmental changes. With additional targeted, experimental research, a framework could be established that uses blue mussel physiology to further indicate impacts of specific environmental conditions on Virginia’s Eastern Shore ecosystems.

No description available.

No description available.