title: Testing broadcast seeding methods to restore urban forests in the presence of seed predators

authors: Overdyck, Elizabeth

subjects: avian seed dispersal

abstract: Forest restoration in urban areas often occurs in isolation from remnant forest, limiting the chances for recolonization by native species. Plants with bird-dispersed seeds can be particularly vulnerable to dispersal limitation and regeneration can be further impeded by non-native seed predators. We used a factorial experiment to investigate broadcast seeding as a method to reintroduce trees with large seeds and fleshy fruits into early successional forests. We assessed rates of seed and fruit loss, germination and seedling establishment in three seed treatments: (1) caging to exclude introduced mammalian seed predators; (2) removal of fleshy fruit pericarp; and (3) placing seeds in nutritionally enriched clay balls. Across all species (Beilschmiedia tawa, Elaeocarpus dentatus, and Litsea calicaris) seeds and fruits accessible to mammalian predators suffered significantly greater loss (58%) than those protected by cages (4%). However, seed and fruit loss in the presence of predators was reduced to only 35% across all species by the treatment combining the removal of fruit flesh and clay ball application to seeds. Establishment of B. tawa seedlings after 1 year was significantly enhanced by the clay ball treatment (12% of seeds sown vs. 6% without clay balls). Very low establishment rates were recorded for E. dentatus and L. calicaris. Broadcast seeding was found to be a viable method of improving regeneration of large-seeded late successional trees and may be a cost-effective alternative to planting saplings. Seedling establishment can be improved with fruit flesh removal and clay ball treatments, especially in the presence of mammalian seed predators.

text: Testing broadcast seeding methods to restore urban forests in the presence of seed predators Forest restoration in urban areas often occurs in isolation from remnant forest, limiting the chances for recolonization by native species. Plants with bird-dispersed seeds can be particularly vulnerable to dispersal limitation and regeneration can be further impeded by non-native seed predators. We used a factorial experiment to investigate broadcast seeding as a method to reintroduce trees with large seeds and fleshy fruits into early successional forests. We assessed rates of seed and fruit loss, germination and seedling establishment in three seed treatments: (1) caging to exclude introduced mammalian seed predators; (2) removal of fleshy fruit pericarp; and (3) placing seeds in nutritionally enriched clay balls. Across all species (Beilschmiedia tawa, Elaeocarpus dentatus, and Litsea calicaris) seeds and fruits accessible to mammalian predators suffered significantly greater loss (58%) than those protected by cages (4%). However, seed and fruit loss in the presence of predators was reduced to only 35% across all species by the treatment combining the removal of fruit flesh and clay ball application to seeds. Establishment of B. tawa seedlings after 1 year was significantly enhanced by the clay ball treatment (12% of seeds sown vs. 6% without clay balls). Very low establishment rates were recorded for E. dentatus and L. calicaris. Broadcast seeding was found to be a viable method of improving regeneration of large-seeded late successional trees and may be a cost-effective alternative to planting saplings. Seedling establishment can be improved with fruit flesh removal and clay ball treatments, especially in the presence of mammalian seed predators.

year: 2013

title: Nutrient removal by algal polyculture in dairy farm effluent

authors: Ishan, Ilisa

abstract: Nutrient pollution from dairy farm effluent, particularly nitrogen (N) and phosphorus (P), significantly contributes to environmental degradation and eutrophication, necessitating effective bioremediation strategies. This study explores the efficacy of algae polyculture E3 in remediating dairy farm wastewater, focusing on nutrient removal and algal growth. Conducted over a 28-day period, the research compares the bioremediation capabilities of algae polyculture in autoclaved and non-autoclaved effluent samples. Findings reveal that algae polyculture demonstrates superior bioremediation performance in non-autoclaved conditions, with growth rates ranging from 8.07 to 10.13 mg L-1 d-1. The algal polyculture achieved significant nutrient removal, eliminating 90.9% of ammonium (NH₄⁺) and 99.1% of phosphate (PO₄³⁻), highlighting its potential in mitigating nutrient pollution. The study underscores the importance of operational conditions, as non-autoclaved environments fostered more robust algal growth and nutrient uptake. Further, the research involved the optimisation of the model data, leading to improved accuracy in simulating the biological removal processes. The optimised model better reflects real-world bioremediation dynamics, facilitating more reliable predictions of algal performance and nutrient cycling. Additionally, the study identifies a 10-day hydraulic retention time (HRT) as optimal for balancing algal biomass growth with nutrient removal, addressing common challenges such as algal washout and inefficiency in nutrient uptake. In conclusion, the findings advocate for the application of algae polyculture E3 in the bioremediation of dairy farm effluent, proposing a sustainable approach to addressing the critical issue of nutrient pollution. By optimizing conditions for algal growth and nutrient removal, this research contributes to the development of more effective environmental management practices.

text: Nutrient removal by algal polyculture in dairy farm effluent Nutrient pollution from dairy farm effluent, particularly nitrogen (N) and phosphorus (P), significantly contributes to environmental degradation and eutrophication, necessitating effective bioremediation strategies. This study explores the efficacy of algae polyculture E3 in remediating dairy farm wastewater, focusing on nutrient removal and algal growth. Conducted over a 28-day period, the research compares the bioremediation capabilities of algae polyculture in autoclaved and non-autoclaved effluent samples. Findings reveal that algae polyculture demonstrates superior bioremediation performance in non-autoclaved conditions, with growth rates ranging from 8.07 to 10.13 mg L-1 d-1. The algal polyculture achieved significant nutrient removal, eliminating 90.9% of ammonium (NH₄⁺) and 99.1% of phosphate (PO₄³⁻), highlighting its potential in mitigating nutrient pollution. The study underscores the importance of operational conditions, as non-autoclaved environments fostered more robust algal growth and nutrient uptake. Further, the research involved the optimisation of the model data, leading to improved accuracy in simulating the biological removal processes. The optimised model better reflects real-world bioremediation dynamics, facilitating more reliable predictions of algal performance and nutrient cycling. Additionally, the study identifies a 10-day hydraulic retention time (HRT) as optimal for balancing algal biomass growth with nutrient removal, addressing common challenges such as algal washout and inefficiency in nutrient uptake. In conclusion, the findings advocate for the application of algae polyculture E3 in the bioremediation of dairy farm effluent, proposing a sustainable approach to addressing the critical issue of nutrient pollution. By optimizing conditions for algal growth and nutrient removal, this research contributes to the development of more effective environmental management practices.

year: 2024

title: Te Arawa– Kaitaki of Te Arawa Lakes

authors: Curtis, Sir Toby

abstract: The Te Arawa Lakes Trust has embarked on a project to develop a Te Arawa Cultural Values Framework, in regard to the 14 lakes located in our tribal region. There are a host of positives that we believe can accrue as an outcome of this exercise. Already the calibre of people acknowledged for their cultural expertise have added a lot by their attendance. Their presence and contribution injected a level of enthusiasm and confidence in the compilation of the final draft. It is hoped that distribution among the wider community will elicit constructive feedback.

text: Te Arawa– Kaitaki of Te Arawa Lakes The Te Arawa Lakes Trust has embarked on a project to develop a Te Arawa Cultural Values Framework, in regard to the 14 lakes located in our tribal region. There are a host of positives that we believe can accrue as an outcome of this exercise. Already the calibre of people acknowledged for their cultural expertise have added a lot by their attendance. Their presence and contribution injected a level of enthusiasm and confidence in the compilation of the final draft. It is hoped that distribution among the wider community will elicit constructive feedback.

year: 2015