Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Handroanthus heptaphyllus (ipê-roxo) species has ecological and commercial importance, being used for various purposes since timber purposes to environmental restoration, and medical purposes. Thus, the present study aimed to evaluate and establish appropriate technical knowledge for the production of forest seeds and seedlings of H. heptaphyllus process. The seeds collected in the municipality of Santa Maria (RS) formed the batch to be studied, this was divided into two portions, one for the experiment 1 and the other 2. In experiment 1, we assessed the degree of humidity - DH ( 4 replicates of 25 seeds ) and electrical conductivity - EC (two quantities of seeds - 25 and 50, and three volumes of distilled water - 25 , 50 and 75 mL). In addition to evaluating different substrates (blotting paper, filter paper, vermiculite, sand, both on and between the arrangements in addition to the scroll), to one with higher germination (G). In experiment 2, seeds were stored for 300 days in three environments (dry and cold room - SSF - 18°C and 49 % Relative Humidity (RH); clammy chamber - CUF - 8°C and 80% RH and, dry chamber and cold - CSF - 7.5ºC and 55% RH). After this period, it was determined DH, EC, G and health. Nursery evaluated the effect of two cartridge volumes (110 and 180 cm³) with four doses of controlled-release fertilizer (CRF), NPK (18-05-09) at doses of 0 (control), 2.5, 5.0 and 7.5 g.L-1. At 180 days after sowing the reviews of height (H), diameter Collectors (DC), H/DC, dry mass and leaf area. In the field underwent seedlings under light intensities of 0 (full sun - PS - control), 18, 50 and 70% shade, evaluated for 360 days checking the survival, H, DC, H/DC, total chlorophyll content, chlorophyll a/chlorophyll b, carotenoid content, initial fluorescence of the chlorophyll maximum photochemical efficiency of photosystem II. The germination of seeds of H. heptaphyllus can be done on sand with initial count (IC) seedlings at 16 and end (EnC) at 19 days after sowing. The storage of seeds of H. heptaphyllus for 300 days can be held in SSF and/or CSF, with the IC and EnC at 9 and 29 days and, at 14 and 23 days, respectively, and this represents an intermediate behavior in relation to desiccation. The CFS was the most suitable for reducing the incidence of pathogens environment. The species is nutritionally demanding responding to high dose of CRF, with a minimum dose of 7.2 g.L-1 to 110 cm³ and 6.1 g.L-1 to 180 cm³, with the potential to respond to doses higher than 7.5 g.L-1. Seedlings to field H. heptaphyllus have high survival and growth suitable for PS, however, not recommended 50 and 70 % shading. There were increased levels of total chlorophyll and carotenoids, and lower chlorophyll a fluorescence. The species in reforestation and restoration of degraded areas, including the PS is recommended. / A espécie Handroanthus heptaphyllus (ipê-roxo) possui importância ecológica e comercial, sendo utilizada em diversos fins desde fins madeireiros até recuperação ambiental, além de fins medicinais. Assim, o presente trabalho teve o objetivo de avaliar e estabelecer técnicas adequadas para o conhecimento do processo de produção de sementes e mudas florestais de H. heptaphyllus. As sementes coletadas no município de Santa Maria (RS)s formaram o lote a ser estudado, esse foi dividido em duas porções, uma destinada ao experimento 1 e outra ao 2. No experimento 1, avaliou-se o grau de umidade GU (4 repetições de 25 sementes) e a condutividade elétrica - CE (duas quantidades de sementes - 25 e 50 e, três volumes de água destilada 25, 50 e 75 mL). Além de avaliar diferentes substratos (papel mata-borrão, papel filtro, vermiculita, areia, ambos nos arranjos sobre e entre, além do rolo de papel), visando um com maior germinação (G). No experimento 2, as sementes foram armazenadas por 300 dias em três ambientes (sala seca e fria SSF 18ºC e 49% de Umidade Relativa (UR); câmara fria e úmida - CUF 8ºC e 80% UR e; câmara seca e fria CSF 7,5ºC e 55% UR). Após esse período, determinou-se o GU, CE, G e sanidade. Em viveiro avaliou-se o efeito de dois volumes de tubete (110 e 180 cm3) com quatro doses de fertilizante de liberação controlada (FLC), NPK (18-05-09), nas doses de 0 (testemunha), 2,5; 5,0 e 7,5 g.L-1. Aos 180 dias após o semeio as avaliações de altura (H), diâmetro coleto (DC), relação H/DC, massas secas e área foliar. No campo submeteu-se as mudas sob intensidades luminosas de 0 (pleno sol PS testemunha), 18, 50 e 70% de sombra, avaliadas durante 360 dias, verificando-se a sobrevivência, H, DC, H/DC, teor de clorofila total, relação clorofila a/clorofila b, teor de carotenoides, fluorescência inicial da clorofila a e eficiência fotoquímica máxima do fotossistema II. O teste de germinação de sementes de H. heptaphyllus pode ser realizado sobre areia, com contagem inicial (PC) de plântulas aos 16 dias após a semeadura e final (UC) aos 19. O armazenamento das sementes de H. heptaphyllus por 300 dias pode ser realizado em SSF e/ou CSF, sendo a PC e UC aos 9 e 29 dias e, aos 14 e 23 dias, respectivamente, sendo que esta apresenta comportamento intermediário em relação ao dessecamento. A CFS foi o ambiente mais adequado para redução da incidência de patógenos. A espécie é exigente nutricionalmente respondendo a elevada dose de FLC, com dose mínima de 7,2 g.L-1 para 110 cm³ e 6,1 g.L-1 para 180 cm³, com potencial para responder a doses superiores a 7,5 g.L-1. Mudas a campo de H. heptaphyllus apresentam sobrevivência elevada e crescimento adequado a PS, porém, não se recomenda 50 e 70% de sombreamento. Houve aumento dos níveis de clorofila total e carotenoides e, menor fluorescência da clorofila a. Recomenda-se a espécie em reflorestamento e recuperação de áreas degradadas, inclusive a PS.

Plantas acumulam elementos químicos devido aos mais variados fatores como atendimento às necessidades estruturais e fisiológicas e características ambientais. Em estudos de biomonitoração, é comum a seleção de uma espécie para a avaliação da qualidade ambiental. A bioacumulação de vários elementos químicos já foi demonstrada para as espécies arbóreas mais abundantes da Mata Atlântica na parcela permanente do Parque Estadual Carlos Botelho (PECB), uma das áreas mais preservadas da Mata Atlântica. Contudo, dado o elevado nível de alteração ambiental e a alta biodiversidade do bioma, torna-se necessário avaliar os padrões de bioacumulação em outras regiões da Mata Atlântica. Uma das areas mais significativas da Mata Atlântica para o Estado de São Paulo é o Parque Estadual da Serra do Mar (PESM), com exemplos de áreas bem preservadas e outras sob grande pressão antrópica. O núcleo Picinguaba é um dos núcleos mais conservados do parque que alcança a zona costeira. Por outro lado, o núcleo Itutinga-Pilões tem sido constantemente impactado por atividades humanas. Por exemplo, há muitos relatos sobre os efeitos da poluição na vegetação próxima aos centros urbanos e complexos industriais de São Paulo e Cubatão. Assumindo-se a hipótese de que a proximidade das unidades de conservação com o oceano e grandes centros urbanos pode influenciar a absorção de elementos químicos por plantas, este trabalho objetivou estudar a complexidade da acumulação de elementos químicos por espécies arbóreas dos núcleos Picinguaba e Itutinga-Pilões do PESM. Folhas de sete espécies arbóreas Alsophila sternbergii, Bathysa australis, Garcinia gardneriana, Guapira opposita, Euterpe edulis, Hyeronima alchorneoides e Virola bicuhyba - foram coletadas em diferentes épocas, assim como o solo sob a projeção das copas das árvores para estimar o índice de bioacumulação solo-folha (IBASF). A quantificação dos elementos químicos foi realizada por meio da análise por ativação neutrônica instrumental (INAA). A bioacumulação foi avaliada pela composição química elementar de solos, folhas e IBASF para todas as espécies. Os solos do núcleo Itutinga-Pilões apresentaram pontos críticos de As nas proximidades das rodovias, os quais podem ser importantes para a sustentabilidade a longo-prazo do ecossistema. As árvores do núcleo Itutinga-Pilões apresentaram um aporte maior de Fe, Th, Zn, Ce, La, Sm e Sc quando comparadas ao núcleo Picinguaba, que apresentou valores mais elevados de Na devido à influência do oceano. Um forte efeito de sazonalidade foi observado para a composição química elementar de folhas, associado à deposição de particulado atmosférico. Este estudo demonstrou a potencialidade do emprego da composição química elementar de árvores nativas e do solo para a avaliação da qualidade ambiental da Mata Atlântica. / Plants accumulate chemical elements due to several factors such as structural and physiological requirements and environmental characteristics. For biomonitoring studies, it is usual to select one species for monitoring the availability of chemical elements. The bioaccumulation of chemical elements has been demonstrated for the most abundant tree species in the Parque Estadual Carlos Botelho (PECB), one of the most preserved areas of the Atlantic Forest. However, due to the high level of environmental alterations and the high biodiversity of this biome, it becomes necessary to assess the bioaccumulation patterns in other regions of the Atlantic forest. A significant area of the Atlantic Forest for the São Paulo State is the Parque Estadual da Serra do Mar (PESM) with well preserved areas as well as regions under heavy anthropogenic pressure. Picinguaba is one of the most conserved PESM bases, reaching the costal zone. On the other hand, the Itutinga-Pilões base has been constantly impacted by human activities. For instance, there are many reports about the pollution effects on vegetation near urban centers and industrial complexes of São Paulo and Cubatão. Assuming the hypothesis that the proximity of the conservation units to the ocean and huge urban and industrial areas can influence the uptake of chemical elements by plants, this study investigated the complexity of the accumulation of chemical elements in tree species of the Picinguaba and Itutinga-Pilões bases of PESM. Leaves of seven tree species Alsophila sternbergii, Bathysa australis, Garcinia gardneriana, Guapira opposita, Euterpe edulis, Hyeronima alchorneoides and Virola bicuhyba - were collected in different periods. Soil under the tree crown projection at the 0-10 cm depth was sampled for estimating the soil-leaf bioaccumulation index (SLBAI). Chemical elements were determined by instrumental neutron activation analysis (INAA). By comparing the soil and leaf mass fractions of chemical elements and SLBAI values, bioaccumulation was assessed for all species from the studied areas. Itutinga-Pilões soil presented As hotspots near roads, which might be important for long-term ecosystem sustainability. Trees from the Itutinga-Pilões base also showed higher uptake of Ce, Fe, La, Sc, Sm and Th compared to the Picinguaba base, which showed high Na values because of the sea influence. A strong effect of seasonality on the leaf chemical element composition was observed, related to the deposition of atmospheric particulate. This study has demonstrated the potentiality of using the chemical composition of native tree and soil for the assessment of environmental quality in the Atlantic Forest.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pepper-rosmarin (Lippia sidoides Cham.) is a medicinal and aromatic plant, native Northeast Region of Brazil, which has an essential oil widely used for its properties as bactericide, fungicide, molluscicide, and larvicide. This paper aimed to characterize and evaluate the performance of accessions of pepper-rosmarin (Lippia sidoides Cham.) native to various States of the Northeast Region, kept in Germplasm Bank at São Cristóvão, Sergipe, Brazil. The first chapter presents the general introduction, the literature review on genetic resources and sustainability of agroecosystems, origin, ethnobotany, and germplasm characterization (morphological, agronomic and chemical). The second chapter presents and discusses the data on the morphological and agronomic characterization of accessions of pepper-rosmarin cultivated in field with seedlings from stem cuttings, using a randomized complete block design with two replications. The evaluated variables were: plant height, fresh and dry matter from leaves and stem, width and length of leaves, color of leaves and stem, crown shape, and content and yield of essential oil. Results showed morphological differences among accessions for color of stem, crown shape, plant height, width and length of leaves and ratio length/width of leaves. For agronomic variables, there were significant differences for content and yield of essential oil with the best and worst performance for accessions LSID-005 and LSID-105, respectively. Third chapter presents the data on performance evaluation of pepper-rosmarin, during two years of field cultivation, for the variables: plant height, fresh and dry matter of stem and leaves, content and yield of essential oil, and the content of chemical components of the essential oil. The higher averages found for content (7,68 %) and yield (56,46 mL plant- 1) essential oil were produced by the accession LSID-105, in 2005, and by LSID-102, in 2006, respectively. The higher averages for content of thymol (90,82 %) and carvacrol (56,05 %) were obtained from the accessions LSID-003 and LSID-104, respectively, both in 2006. The accession LSID-104, native to Sergipe State, presented carvacrol as major chemical component. All the other accessions presented thymol as major chemical component. All the accessions, in both years, presented phenotypical variability for all the evaluated variables, except for content of terpil-4-ol. Fourth chapter presents the evaluation of influence of dry and rainy seasons on the performance of accessions of pepper-rosmarin, using the variables: plant height, dry matter of leaves, content and yield of essential oil and content of chemical components of the essential oil. For the majority of the studied accessions, the thymol content was higher during the rainy season. LSID-102 accession presented high yield of essential oil (56,46 mL plant- 1) and thymol content between 47,97 % and 64,95 %. LSID-003 accession yielded 10,06 mL plant-1 of essential oil amd thymol content of 90,02 %. LSID-104 accession presented high content of carvacrol (54,68%) and low content of thymol (7,88 %). Fifth chapter presents the evaluation of the influence of leaves dehydration (at 40 °C for 5 days) on the content of essential oil and its chemical components of 11 accessions of pepper-rosmarin harvested during dry and rainy season. Generally, drying of leaves modified the content of most of the chemical constituents. In relation of the major iv chemical constituents, drying modified thymol content, but did not modified the carvacrol content of the essential oil of the pepper-rosmarin accessions. / Alecrim-pimenta (Líppia sidoides Cham.) é uma planta medicinal e aromática, nativa do Nordeste do Brasil, cujo óleo essencial é utilizado em virtude de suas propriedades bactericida, fungicida, moluscida e larvicida. Este trabalho visou caracterizar e avaliar o comportamento de acessos de alecrim-pimenta (Lippia sidoides Cham.), de vários Estados do Nordeste do Brasil, mantidos em Banco Ativo de Germoplasma em São Cristóvão. No primeiro capítulo, apresentou-se a introdução geral do trabalho, o referencial teórico sobre recursos genéticos e sustentabilidade de agroecossistemas, a origem, os aspectos botânicos e de uso de alecrim-pimenta, a conservação de recursos genéticos e a caracterização de germoplasma (caracterização morfológica, agronômica e química). O segundo capítulo consistiu da caracterização morfológica e agronômica de acessos de alecrim-pimenta cultivados em campo, utilizando-se delineamento experimental em blocos ao acaso com duas repetições. Foram avaliadas as variáveis: altura de planta, massa fresca e seca de folha e caule, largura e comprimento de folha, cor de folha, formato de copa, teor e rendimento de óleo essencial. Os resultados mostraram diferenças morfológicas nos acessos para as variáveis: cor de caule, formato de copa, altura de planta, comprimento e largura de folha e relação comprimento/largura de folha. Para as características agronômicas, foram evidenciadas diferenças significativas para teor e rendimento óleo essencial, sendo o acesso LSID-005 o mais promissor e o acesso LSID-105 o menos promissor. No terceiro capítulo estudou-se o comportamento de acessos de alecrim-pimenta em dois anos de cultivo, e foram avaliadas as variáveis: altura de planta, massa fresca de caule e folha, teor, rendimento e teores dos constituintes químicos do óleo essencial. As maiores médias encontradas para os caracteres teor e rendimento de óleo essencial foram do acesso LSID-105, com 7,68 % no ano de 2005, e do acesso LSID-102, com 56,46 mL planta-1 no ano de 2006, respectivamente. As maiores médias de timol e de carvacrol foram encontradas no acesso LSID-003, com 90,82 % e do acesso LSID-104, com 56,05 % respectivamente, ambos no ano de 2006. O acesso LSID-104, oriundo do Estado de Sergipe, apresentou como constituinte químico majoritário o carvacrol. Os demais acessos têm o timol como constituinte químico majoritário. Todos os acessos, nos dois anos de cultivo, apresentaram variabilidade fenotípica para todas as variáveis analisadas, exceto para teor de terpil 4-ol. No quarto capítulo, avaliou-se a influência das épocas seca e chuvosa no comportamento de acessos de alecrim-pimenta, avaliandose as variáveis: massa fresca e seca de folha, teor e rendimento do óleo essencial e os teores dos constituintes químicos do óleo essencial. Observou-se que, para a maioria dos acessos de alecrim-pimenta estudados, o teor de timol é maior na época chuvosa do que na seca. O acesso LSID-102 apresentou alto rendimento de óleo essencial, porém com teor de timol entre 47,97 % e 64,95 %. O acesso LSID-003 apresentou rendimento de óleo essencial de 10,06 mL planta-1 e teor de timol de 90,02 % e, o acesso LSID-104 apresentou alto teor de carvacrol (média de 54,68 %) e baixo teor de timol (média de 7,88 %). No quinto capítulo, estudou-se a influência da secagem das folhas no óleo essencial de acessos de alecrim-pimenta. Testou-se a influência da secagem das folhas a 40º C por cinco dias em 11 acessos de alecrim-pimenta, colhidas nas estações seca e chuvosa. Avaliaram-se o teor de óleo essencial e os teores dos constituintes químicos no ii óleo essencial. A secagem proporcionou redução de teor de óleo essencial de alecrimpimenta quando colhido na estação seca. Em geral, a secagem alterou os teores da maioria dos constituintes químicos. Em relação aos constituintes químicos majoritários, a secagem alterou o teor de timol, mas não alterou o teor de carvacrol do óleo essencial de acessos de alecrim-pimenta.

No description available.

Human activities are increasing the occurrence of megafires that have the potential to alter the ecology of forest ecosystems. The objective of this study was to understand the impact of a 610 km2 megafire on patterns of forest regeneration and herbivory of three forest types (aspen/fir, oak/maple, and pinyon/juniper) within the burn scar. Sapling density, meristem removal, and height were measured across a transect network spanning the area of the burn scar over three years from 2019-2021. The network consisted of 17 burned/unburned transect pairs in adjacent burned/unburned forest stands (6 aspen/fir, 5 oak/maple, and 6 pinyon/juniper). Species that regenerated through sprouting generally responded positively to fire while regeneration from seed showed very little post-fire response. Browse pressure was concentrated on deciduous tree species and tended to be greater in burned areas but the effect diminished over time. Meristem removal of sprouting species was below the critical threshold resulting in positive vertical growth across years. Our results indicate that forest regeneration within the megafire scar was generally positive and experienced sustainable levels of ungulate browsing that are likely to result in forest recruitment success. Novel fire regimes are becoming increasingly common and megafires have burned across ecotonal boundaries across multiple forest types. Plant community structure and composition may be critically affected by changing fire regimes. Our objective was to investigate how a megafire that burned across multiple forest types impacted understory plant community assembly and biodiversity. Paired vegetation transects were installed in burned and unburned areas across aspen/fir, oak/maple, and pinyon/juniper forests within the 2018 Pole Creek Megafire burn scar. Percent cover of understory plants was measured in the summer of 2022 and plants were identified to the species level. Richness and diversity indices were then calculated and analyzed using mixed effects models. Fire decreased species richness of the aspen/fir forest understory and increased plant cover in pinyon/juniper forests, while not significantly impacting oak/maple understories. The significant effects of fire were largely driven by changes in forb species. Fire decreased the richness of native plants in aspen/fir forests but increased the richness of non-native plants in oak/maple and pinyon/juniper forests. Non-native plant abundance also increased in post-fire pinyon/juniper forests. Our results suggest that forest understory communities show variable responses to megafires that burn across multiple forest types with important implications for post-fire plant community structure, diversity, and invasibility. Large mammal herbivores (ungulates) are increasing in number and spreading into novel habitats throughout the world. Their impact on forest understory plant communities is strong and varies by herbivore, plant growth form, and season. The objective of this study was to determine the individual and collective herbivory impacts of native versus domestic ungulates on the understory plant community composition of post-fire aspen forests. Four-way fencing treatments were installed in 2012 to separate ungulate species, and Daubenmire frames were used to collect percent cover estimates for each understory plant species. Vegetation data were later used to calculate richness and diversity indices. Total understory plant cover, richness, and diversity were not significantly impacted by the herbivory fencing treatment. However, woody plant species' percent cover was 90% greater in full ungulate exclusion plots than in the fenceless controls. Herbivores likely targeted woody plant species due to their high nutrient levels that last longer into the winter than those of forb or graminoid species. Herbivory treatment did not affect non-native species. Our results indicate that herbivore fencing can protect forest understory plant communities, particularly the woody species. Successful regeneration of woody species can benefit the diversity of the entire understory plant community and preserve forest structure.

A study was conducted to determine what impact high white-tailed deer (Odocoileus virginianus) densities were having on the native grasslands of a tallgrass: aspen forest tract embedded within an agro-urban setting. Due to excessive spring moisture, row-crops were unavailable the first year. Using microhistological fecal analysis to determine dietary composition, deer were assessed to be placing the site’s favoured native plant species at risk of extirpation. Measuring woody stem abundance and height along and near the prairie: forest ecotone, deer were found to restructure woody growth but not directly influence encroachment rates. Indirectly, however, deer facilitated forest encroachment and prairie degradation through seed dispersal, nitrogen deposition, gap-dynamics, and trampling. Comparing dietary composition to nutritional data, deer grazed to maximize fitness, selecting foods high in IVDMD, minimizing energy expenditure, and optimizing CP. High crop CP was offset by intensively grazing particular native plants. ADF was an effective nutritional marker, not AIA.

A study was conducted to determine what impact high white-tailed deer (Odocoileus virginianus) densities were having on the native grasslands of a tallgrass: aspen forest tract embedded within an agro-urban setting. Due to excessive spring moisture, row-crops were unavailable the first year. Using microhistological fecal analysis to determine dietary composition, deer were assessed to be placing the site’s favoured native plant species at risk of extirpation. Measuring woody stem abundance and height along and near the prairie: forest ecotone, deer were found to restructure woody growth but not directly influence encroachment rates. Indirectly, however, deer facilitated forest encroachment and prairie degradation through seed dispersal, nitrogen deposition, gap-dynamics, and trampling. Comparing dietary composition to nutritional data, deer grazed to maximize fitness, selecting foods high in IVDMD, minimizing energy expenditure, and optimizing CP. High crop CP was offset by intensively grazing particular native plants. ADF was an effective nutritional marker, not AIA.

Thesis (MScFor )--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Species-rich Renosterveld vegetation does not return to old agricultural fields even after many years (10-20) of abandonment. In most cases the fields are slowly taken over by non-indigenous species, particularly alien pasture grasses and African lawn grass. While poor survival of indigenous seedlings due to competition, grazing or any other establishment constraints, might explain the failure of natural vegetation to colonise old fields, here I am testing the hypothesis that recolonisation by indigenous plant species is limited by seed dispersal. I have quantified changes in seed density with distance from the natural vegetation into old fields using seed traps and soil seed bank assessment. I have also looked at seed dispersal in the dung of large herbivores. Shrubs (with the exception of Eytropappus rhinocerotis) were poorly represented in the seed rain indicating that they might be seed limited. Dicerothamnus rinocerotis (a dominant shrub in Renosterveld) and certain geophytes (that were recovered in the soil bank) have proven that seed dispersal is not the primary constraint to their return to ploughed fields. Dicerothamnus rinocerotis produces a large number of seeds that are dispersed long distances into the old field and a number of geophytes were well represented in the soil bank. Large herbivores are dispersing a lot of herbaceous forbs in their dung but make very little contribution to the dispersal of indigenous tussock grass and shrubs. Seeds of indigenous Renosterveld tussock grasses (e.g Tribolium hispidum) were restricted to the edge of the natural vegetation. My research has shown that some indigenous seeds, particularly those dispersed in wind and through large mammals, do reach the old ploughed field. I therefore conclude that seed dispersal is not the primary constraint to the natural recovery of populations of some indigenous plant species on old fields, but may limit recovery of certain indigenous geophytes, grasses and shrubs. / AFRIKAANSE OPSOMMING: Spesie-ryke Renosterveld plantegroei hervestig nie op ou landerye nie, selfs ná baie jare (l0-20) van verlating. Oor die algemeen word hierdie grond stadig oorgeneem deur uitheemse spesies, veral uitheemse weidingsgrasse en kweekgras. Terwyl swak oorlewing van inheemse saailinge as gevolg van kompetisie, weiding of enige ander vestigingsbeperkinge, die mislukte vestiging van natuurlike plantegroei op ou benutte grond kan verduidelik, toets ek hier die hipotese dat hervestiging deur inheemse plantspesies deur saadverspreiding beperk word. Ek het veranderinge in saaddigtheid oor afstand vanaf die natuurlike plantegroei na ou landerye gekwantifiseer, deur gebruik te maak van saadopvangsvalle en sand saadbank beraminge. Ek het ook gekyk na saadverspreiding in die mis van groot herbivore. Struike (behalwe Eytropappus rhinocerotis) was swak verteenwoordig in die "saadreën", wat mag toon dat struike saadbeperk is. Eytropappus rhinocerotis ('n dominante struik in Renosterveld) en sekere geofiete (wat in die saadbank gevind is) het bewys dat saadverspreiding nie die hoofbeperking is vir hulle terugkeer na geploegde lande nie. Eytropappus rhinocerotis produseer 'n groot hoeveelheid saad wat oor groot afstande oor die ou landerye versprei word en 'n aantal geofiete was goed verteenwoordig in die saadbank. Groot herbivore versprei 'n groot hoeveelheid kruidagtige forbe in hulle mis, maar maak 'n baie klein bydrae tot die verspreiding van inheemse polgras en struike. Saad van inheemse Renosterveld polgrasse (bv. Tribolium hispidum) was beperk tot die some van die natuurlike plantegroei. My navorsing het getoon dat sommige inheemse saad, veral dié wat deur die wind en deur groot herbivore versprei word, wel die ou geploegde landerye bereik. Ek maak dus die gevolgtrekking dat saadverspreiding nie die hoofbeperking is vir die natuurlike herstel van populasies van sommige inheemse plantspesies op ou landerye nie, maar mag die herstel van sekere inheemse geofiete, grasse en struike beperk.

The objective of this project is to develop an activity guide for the California native plant trail located adjacent to the San Bernardino County Museum that allows families to discover native California plants while increasing environmental and cultural sensitivity.