Africa's miombo woodlands constitute one of the most important dry tropical forests on earth, yet the hydraulic function of these woodlands remains poorly researched. Given the current predictions of increased aridity by the end of this century in the miombo ecoregion, understanding the likely response of miombo woodlands tree species to water stress is crucial in planning adaptation strategies. Predicting the response of miombo woodlands to future climate trends is hampered by a lack of knowledge on the physiology of the common miombo woodlands tree species. In particular, plant-water relations for this woodlands type are not well understood. An understanding of plant-water relations for this woodlands type will provide insights into how water limits tree species distribution in this ecosystem. This will also improve our prediction model on the likely response of this ecosystem to predicted climate change. For this reason, the overall objective of this research was to evaluate the hydraulic architecture and xylem vulnerability to cavitation for nine principal miombo woodlands tree species differing in drought tolerance ability and habitat preference. This was achieved by; examining the hydraulic properties and evaluating the extent to which each hydraulic design was vulnerable to water stress-induced xylem cavitation; investigating how seasonal changes in plant-water relations influences seasonal patterns of leaf display and; analyzing the relationship between stem hydraulic supply and leaf functional traits related to drought tolerance ability. This research has found that drought-intolerant tree species with mesic specialization have more efficient stem hydraulic systems than co-occurring habitat broad ranging species. Broad ranging tree species attain wider habitat distribution by adjusting their hydraulic supply in response to changing ecosystem water availability. The finding that hydraulic properties differ significantly between tree species with contrasting habitat preference suggests that tree hydraulic design may have some adaptive ecological role in influencing species habitat preferences in miombo woodlands. The evaluation of xylem vulnerability to cavitation revealed that mesic specialized tree species were more vulnerable to water stress-induced cavitation than habitat broad ranging tree species. Vulnerability to cavitation in individuals from the same broad-ranging species growing in contrasting habitats showed only marginal and statistically insignificant (P > 0.05) differences between wet and dry sites. In the investigation of the influence of seasonal changes in stem water relations on seasonal leaf display, seasonal rhythms in stem water status were found to exert significant controls on leaf phenology. Mesic specialists had strong stem water controls throughout the year in comparison to broad ranging tree species. An analysis of the relationship between stem hydraulic supply and leaf functional traits suggests that stem hydraulic supply constrains leaf biomass allocation patterns among miombo tree species. Mesic specialists tend to invest more in leaf longevity than broad ranging tree species. This thesis has uncovered some interesting relationships between plant-water-relations and the distribution of miombo woodlands tree species. These results lead to the conclusion that in an event of increased ecosystem drying under future climate trends, tree species with mesic specialisation are at a greater risk of experiencing cavitation related species mortality than broad ranging ones.

Increased nutrient availability globally has the potential to affect community functional composition of plants in nutrient limited environments, such as coastal grassland systems. Stability of these systems are threatened worldwide by urbanization, as well as effects of sea level rise and increased frequency and intensity of storms, and atmospheric N deposition, associated with climate change. Annual net primary productivity (ANPP), species composition, and functional traits (community weighted specific leaf area (CWSLA), leaf area index (LAI), growth form and photosynthetic pathway) were measured across four treatments to assess multiple resource limitation of nitrogen (N) and phosphorus (P) and functional community response in a coastal grassland on Hog Island, VA within the Virginia Coast Reserve, Long Term Ecological Research Network (LTER) applied at a rate of 10 g m-2 yr-1 Nutrient enrichment did not alter species diversity or richness. ANPP was highest in plots receiving any type of nitrogen enrichment, and was higher than expected of low nutrient systems. CWSLA was significantly higher in NP plots, and was lower than other grasslands. P treatments were not significantly different from controls. Graminoid species, specifically C4 species responded with higher ANPP than C3 forbs or graminoids within treatments. Evidence of synergistic NP effects were seen on community level resource allocation and leaf construction, but no significant species changes occurred over a 1-year time span. These results have expanded the knowledge of functional response to increased nutrient availability in an understudied, coastal grassland, which are at high risk to being lost to sea level rise and anthropogenic development and inform community assembly processes in stressful environments.

Sunflower is grown worldwide for oil production. In Australia, sunflower is under intense competition from canola as an oil crop. Confectionery sunflower aimed for the overseas snack food market is a potential opportunity for Australian farmers due to its ability to provide off-season supply to the major market located mainly in the northern hemisphere. To serve this aim, new confectionery sunflower hybrids adapted to Australian production system with drought tolerance, large achenes, high self-fertility and rust resistance are of paramount importance. The objectives of this project were to understand the genetic inheritance and genetic linkage relationships of the above traits and also to identify linked DNA markers with the potential for marker-assisted selection (MAS). The inheritance of achene-length was studied in a 12 x 12 diallel and a 14 x 12 North Carolina design II (NC II) mating design. Achene-length was evaluated under three environments for each mating design. Genetic correlation among all five achene-size related traits (achene-length, -width, - thickness and also kernel-length and -width) and 100-achene weight were moderate to high. Narrow-and broad-sense heritability for achene-length was moderate to high and similar for each design. The general combining ability (GCA) and maternal effects were found to be the main genetic factors controlling achene-length and each accounted for around 45% of the total genotypic variance. The inheritance of self-fertility (SF) was assessed with the same 12 x 12 diallel mating design evaluated in two environments. The 12 parents also displayed various levels of SF in addition to a wide range of achene-length. Negative genetic correlations between SF and all five achene-size related traits and 100-achene weight were observed. Modelling achene-length as a covariate revealed that certain pre-pollination floret characteristics represented by achene-length at maturity strongly affects SF in sunflower. When the effect of achene-length was removed statistically as a covariate, the specific combining ability (SCA) effect increased dramatically and became the major factor (other than pre-pollination floret characteristics) for SF determination and accounted for 65% of the total variance. Long achene genotypes tended to have low SF and a positive SCA effect was observed more frequently in F1 hybrids that involved small achene lines. The broad sense heritability was moderate (0.663 ± 0.017), while the estimate of narrow-sense heritability was nearly zero. A segregating F6:7 recombinant inbred line population with 239 progeny was developed from a cross between HaR4, a low delta (Δ), high transpiration efficiency (TE), sunflower line with rust resistance but relatively low SF, and SA52 with all the characteristics in the opposite direction. The population was evaluated in two environments for three TE-related traits including Δ, specific leaf weight (SLW) and chlorophyll content (CC) and four agronomic traits i.e. days to flowering (DTF), plant height (PlantH), SF and rust resistance (RustR). A linkage map 1074.6 cM in length with 138 SSR and 37 ISSR markers consisting of 19 linkage groups was constructed. Spatially adjusted BLUPs were used in QTL analysis for individual and combined environments. Altogether, 10 QTL were identified for Δ, SLW and CC at individual environments, and 7 were detected by a combined analysis. Sixteen QTL were identified for 4 agronomic traits and 14 of them were confirmed by a combined analysis. Significant linkage among all three TE related traits was discovered on linkage group 4 (LG4), where alleles from one parent had the same direction of influence on TE which suggested either coupling phase linkage or pleiotropy. QTL for SF and RustR were closely linked on LG13. An F2 population with 502 progeny developed from a cross between Jumbo, a large achene confectionery sunflower line, and RIL25, an oilseed small achene line, was evaluated for five achene-size related traits in a single field trial. Using a subset of 178 progeny a framework genetic linkage map, 899.7 cM in length, containing 128 SSR markers and 23 ISSR markers was constructed with 18 linkage groups. Based on the results of a simulated QTL analysis, a modified selective genotyping strategy was employed for QTL analysis with 178 F2 individuals (128 randomly selected, 25 shortest achene F2’s and 25 longest achene F2’s). Altogether 18 achene-size related QTL with small effects were identified. Achene-size related genes characteristically expressed additive gene action although several alleles were partially recessive towards the large achene parent. The 18 identified achene-size related QTL were validated in the same diallel mating experiment mentioned above. Significant marker-trait associations were detected for 15 QTL. In addition to 12 significant alleles detected from the F2 population, 12 additional alleles associated with achene-size traits were revealed after the analysis with the diallel. These markers are ready to be used in MAS for confectionery sunflower breeding. Great steps have been made in obtaining essential knowledge of inheritance and linkage of target traits for breeding confectionery sunflower adapted to Australian production environments. The identified markers can be used in MAS and further enhance the breeding process.

Sunflower is grown worldwide for oil production. In Australia, sunflower is under intense competition from canola as an oil crop. Confectionery sunflower aimed for the overseas snack food market is a potential opportunity for Australian farmers due to its ability to provide off-season supply to the major market located mainly in the northern hemisphere. To serve this aim, new confectionery sunflower hybrids adapted to Australian production system with drought tolerance, large achenes, high self-fertility and rust resistance are of paramount importance. The objectives of this project were to understand the genetic inheritance and genetic linkage relationships of the above traits and also to identify linked DNA markers with the potential for marker-assisted selection (MAS). The inheritance of achene-length was studied in a 12 x 12 diallel and a 14 x 12 North Carolina design II (NC II) mating design. Achene-length was evaluated under three environments for each mating design. Genetic correlation among all five achene-size related traits (achene-length, -width, - thickness and also kernel-length and -width) and 100-achene weight were moderate to high. Narrow-and broad-sense heritability for achene-length was moderate to high and similar for each design. The general combining ability (GCA) and maternal effects were found to be the main genetic factors controlling achene-length and each accounted for around 45% of the total genotypic variance. The inheritance of self-fertility (SF) was assessed with the same 12 x 12 diallel mating design evaluated in two environments. The 12 parents also displayed various levels of SF in addition to a wide range of achene-length. Negative genetic correlations between SF and all five achene-size related traits and 100-achene weight were observed. Modelling achene-length as a covariate revealed that certain pre-pollination floret characteristics represented by achene-length at maturity strongly affects SF in sunflower. When the effect of achene-length was removed statistically as a covariate, the specific combining ability (SCA) effect increased dramatically and became the major factor (other than pre-pollination floret characteristics) for SF determination and accounted for 65% of the total variance. Long achene genotypes tended to have low SF and a positive SCA effect was observed more frequently in F1 hybrids that involved small achene lines. The broad sense heritability was moderate (0.663 ± 0.017), while the estimate of narrow-sense heritability was nearly zero. A segregating F6:7 recombinant inbred line population with 239 progeny was developed from a cross between HaR4, a low delta (Δ), high transpiration efficiency (TE), sunflower line with rust resistance but relatively low SF, and SA52 with all the characteristics in the opposite direction. The population was evaluated in two environments for three TE-related traits including Δ, specific leaf weight (SLW) and chlorophyll content (CC) and four agronomic traits i.e. days to flowering (DTF), plant height (PlantH), SF and rust resistance (RustR). A linkage map 1074.6 cM in length with 138 SSR and 37 ISSR markers consisting of 19 linkage groups was constructed. Spatially adjusted BLUPs were used in QTL analysis for individual and combined environments. Altogether, 10 QTL were identified for Δ, SLW and CC at individual environments, and 7 were detected by a combined analysis. Sixteen QTL were identified for 4 agronomic traits and 14 of them were confirmed by a combined analysis. Significant linkage among all three TE related traits was discovered on linkage group 4 (LG4), where alleles from one parent had the same direction of influence on TE which suggested either coupling phase linkage or pleiotropy. QTL for SF and RustR were closely linked on LG13. An F2 population with 502 progeny developed from a cross between Jumbo, a large achene confectionery sunflower line, and RIL25, an oilseed small achene line, was evaluated for five achene-size related traits in a single field trial. Using a subset of 178 progeny a framework genetic linkage map, 899.7 cM in length, containing 128 SSR markers and 23 ISSR markers was constructed with 18 linkage groups. Based on the results of a simulated QTL analysis, a modified selective genotyping strategy was employed for QTL analysis with 178 F2 individuals (128 randomly selected, 25 shortest achene F2’s and 25 longest achene F2’s). Altogether 18 achene-size related QTL with small effects were identified. Achene-size related genes characteristically expressed additive gene action although several alleles were partially recessive towards the large achene parent. The 18 identified achene-size related QTL were validated in the same diallel mating experiment mentioned above. Significant marker-trait associations were detected for 15 QTL. In addition to 12 significant alleles detected from the F2 population, 12 additional alleles associated with achene-size traits were revealed after the analysis with the diallel. These markers are ready to be used in MAS for confectionery sunflower breeding. Great steps have been made in obtaining essential knowledge of inheritance and linkage of target traits for breeding confectionery sunflower adapted to Australian production environments. The identified markers can be used in MAS and further enhance the breeding process.

Sunflower is grown worldwide for oil production. In Australia, sunflower is under intense competition from canola as an oil crop. Confectionery sunflower aimed for the overseas snack food market is a potential opportunity for Australian farmers due to its ability to provide off-season supply to the major market located mainly in the northern hemisphere. To serve this aim, new confectionery sunflower hybrids adapted to Australian production system with drought tolerance, large achenes, high self-fertility and rust resistance are of paramount importance. The objectives of this project were to understand the genetic inheritance and genetic linkage relationships of the above traits and also to identify linked DNA markers with the potential for marker-assisted selection (MAS). The inheritance of achene-length was studied in a 12 x 12 diallel and a 14 x 12 North Carolina design II (NC II) mating design. Achene-length was evaluated under three environments for each mating design. Genetic correlation among all five achene-size related traits (achene-length, -width, - thickness and also kernel-length and -width) and 100-achene weight were moderate to high. Narrow-and broad-sense heritability for achene-length was moderate to high and similar for each design. The general combining ability (GCA) and maternal effects were found to be the main genetic factors controlling achene-length and each accounted for around 45% of the total genotypic variance. The inheritance of self-fertility (SF) was assessed with the same 12 x 12 diallel mating design evaluated in two environments. The 12 parents also displayed various levels of SF in addition to a wide range of achene-length. Negative genetic correlations between SF and all five achene-size related traits and 100-achene weight were observed. Modelling achene-length as a covariate revealed that certain pre-pollination floret characteristics represented by achene-length at maturity strongly affects SF in sunflower. When the effect of achene-length was removed statistically as a covariate, the specific combining ability (SCA) effect increased dramatically and became the major factor (other than pre-pollination floret characteristics) for SF determination and accounted for 65% of the total variance. Long achene genotypes tended to have low SF and a positive SCA effect was observed more frequently in F1 hybrids that involved small achene lines. The broad sense heritability was moderate (0.663 ± 0.017), while the estimate of narrow-sense heritability was nearly zero. A segregating F6:7 recombinant inbred line population with 239 progeny was developed from a cross between HaR4, a low delta (Δ), high transpiration efficiency (TE), sunflower line with rust resistance but relatively low SF, and SA52 with all the characteristics in the opposite direction. The population was evaluated in two environments for three TE-related traits including Δ, specific leaf weight (SLW) and chlorophyll content (CC) and four agronomic traits i.e. days to flowering (DTF), plant height (PlantH), SF and rust resistance (RustR). A linkage map 1074.6 cM in length with 138 SSR and 37 ISSR markers consisting of 19 linkage groups was constructed. Spatially adjusted BLUPs were used in QTL analysis for individual and combined environments. Altogether, 10 QTL were identified for Δ, SLW and CC at individual environments, and 7 were detected by a combined analysis. Sixteen QTL were identified for 4 agronomic traits and 14 of them were confirmed by a combined analysis. Significant linkage among all three TE related traits was discovered on linkage group 4 (LG4), where alleles from one parent had the same direction of influence on TE which suggested either coupling phase linkage or pleiotropy. QTL for SF and RustR were closely linked on LG13. An F2 population with 502 progeny developed from a cross between Jumbo, a large achene confectionery sunflower line, and RIL25, an oilseed small achene line, was evaluated for five achene-size related traits in a single field trial. Using a subset of 178 progeny a framework genetic linkage map, 899.7 cM in length, containing 128 SSR markers and 23 ISSR markers was constructed with 18 linkage groups. Based on the results of a simulated QTL analysis, a modified selective genotyping strategy was employed for QTL analysis with 178 F2 individuals (128 randomly selected, 25 shortest achene F2’s and 25 longest achene F2’s). Altogether 18 achene-size related QTL with small effects were identified. Achene-size related genes characteristically expressed additive gene action although several alleles were partially recessive towards the large achene parent. The 18 identified achene-size related QTL were validated in the same diallel mating experiment mentioned above. Significant marker-trait associations were detected for 15 QTL. In addition to 12 significant alleles detected from the F2 population, 12 additional alleles associated with achene-size traits were revealed after the analysis with the diallel. These markers are ready to be used in MAS for confectionery sunflower breeding. Great steps have been made in obtaining essential knowledge of inheritance and linkage of target traits for breeding confectionery sunflower adapted to Australian production environments. The identified markers can be used in MAS and further enhance the breeding process.

Sunflower is grown worldwide for oil production. In Australia, sunflower is under intense competition from canola as an oil crop. Confectionery sunflower aimed for the overseas snack food market is a potential opportunity for Australian farmers due to its ability to provide off-season supply to the major market located mainly in the northern hemisphere. To serve this aim, new confectionery sunflower hybrids adapted to Australian production system with drought tolerance, large achenes, high self-fertility and rust resistance are of paramount importance. The objectives of this project were to understand the genetic inheritance and genetic linkage relationships of the above traits and also to identify linked DNA markers with the potential for marker-assisted selection (MAS). The inheritance of achene-length was studied in a 12 x 12 diallel and a 14 x 12 North Carolina design II (NC II) mating design. Achene-length was evaluated under three environments for each mating design. Genetic correlation among all five achene-size related traits (achene-length, -width, - thickness and also kernel-length and -width) and 100-achene weight were moderate to high. Narrow-and broad-sense heritability for achene-length was moderate to high and similar for each design. The general combining ability (GCA) and maternal effects were found to be the main genetic factors controlling achene-length and each accounted for around 45% of the total genotypic variance. The inheritance of self-fertility (SF) was assessed with the same 12 x 12 diallel mating design evaluated in two environments. The 12 parents also displayed various levels of SF in addition to a wide range of achene-length. Negative genetic correlations between SF and all five achene-size related traits and 100-achene weight were observed. Modelling achene-length as a covariate revealed that certain pre-pollination floret characteristics represented by achene-length at maturity strongly affects SF in sunflower. When the effect of achene-length was removed statistically as a covariate, the specific combining ability (SCA) effect increased dramatically and became the major factor (other than pre-pollination floret characteristics) for SF determination and accounted for 65% of the total variance. Long achene genotypes tended to have low SF and a positive SCA effect was observed more frequently in F1 hybrids that involved small achene lines. The broad sense heritability was moderate (0.663 ± 0.017), while the estimate of narrow-sense heritability was nearly zero. A segregating F6:7 recombinant inbred line population with 239 progeny was developed from a cross between HaR4, a low delta (Δ), high transpiration efficiency (TE), sunflower line with rust resistance but relatively low SF, and SA52 with all the characteristics in the opposite direction. The population was evaluated in two environments for three TE-related traits including Δ, specific leaf weight (SLW) and chlorophyll content (CC) and four agronomic traits i.e. days to flowering (DTF), plant height (PlantH), SF and rust resistance (RustR). A linkage map 1074.6 cM in length with 138 SSR and 37 ISSR markers consisting of 19 linkage groups was constructed. Spatially adjusted BLUPs were used in QTL analysis for individual and combined environments. Altogether, 10 QTL were identified for Δ, SLW and CC at individual environments, and 7 were detected by a combined analysis. Sixteen QTL were identified for 4 agronomic traits and 14 of them were confirmed by a combined analysis. Significant linkage among all three TE related traits was discovered on linkage group 4 (LG4), where alleles from one parent had the same direction of influence on TE which suggested either coupling phase linkage or pleiotropy. QTL for SF and RustR were closely linked on LG13. An F2 population with 502 progeny developed from a cross between Jumbo, a large achene confectionery sunflower line, and RIL25, an oilseed small achene line, was evaluated for five achene-size related traits in a single field trial. Using a subset of 178 progeny a framework genetic linkage map, 899.7 cM in length, containing 128 SSR markers and 23 ISSR markers was constructed with 18 linkage groups. Based on the results of a simulated QTL analysis, a modified selective genotyping strategy was employed for QTL analysis with 178 F2 individuals (128 randomly selected, 25 shortest achene F2’s and 25 longest achene F2’s). Altogether 18 achene-size related QTL with small effects were identified. Achene-size related genes characteristically expressed additive gene action although several alleles were partially recessive towards the large achene parent. The 18 identified achene-size related QTL were validated in the same diallel mating experiment mentioned above. Significant marker-trait associations were detected for 15 QTL. In addition to 12 significant alleles detected from the F2 population, 12 additional alleles associated with achene-size traits were revealed after the analysis with the diallel. These markers are ready to be used in MAS for confectionery sunflower breeding. Great steps have been made in obtaining essential knowledge of inheritance and linkage of target traits for breeding confectionery sunflower adapted to Australian production environments. The identified markers can be used in MAS and further enhance the breeding process.

Native to Europe and Asia, Lythrum salicaria is an invasive element on some other continents. Plants in the invaded areas are more robust, higher, and generally more successful compared to individuals in their original area. Based on my results these characteristics cannot be explained by neither higher photosynthesis, chlorophyll and carotenoid mass, nor specific leaf area.

This study examines the role of deffensive host-plant traits in structuring the community of leaf-chewing insects living on willows. Host-plant phylogeny was reconstructed and leaf morphology and content of three different groups of secondary metabolites were measured. Relationships between defensive leaf traits were examined and their influence on insect community structure was analyzed.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was conducted in the city of Restinga Sêca, RS, with the objective to analyze the productivity, quality, botanical composition and biological characteristics of native pasture in response to fertilization and water availability. The fertilization increased native pastures productivity. The dry matter total accumulation rate, at dry or wet area, both fertilized, was 102 kg/ha/day. In the same areas, not fertilized, was 47 and 41 kg/ha/day, respectively. For green matter, the fertilization also increased the productivity, reaching accumulation rates of 70 and 93 kg/ha/day for dry and wet areas, respectively. In these not fertilized areas, the rates were 29 and 25 kg/ha/day. Furthermore, increased nitrogen and crude protein rates in plant tissues and mineral matter quantity in the plots. Water availability influenced on pasture components, as the water availability was increased, lower amount of components such as strait leaf, broad leaf and legumes and higher amount of neutral detergent fiber in tissues were observed, especially in spring period. Fertilization as well as water availability decreased the wealth of species, causing domination of some species already adapted to these conditions. Two functional groups were formed with vegetal biological characteristics, a group of capture of resources, with a high specific leaf area (SLA) (26) and low dry matter content (DMC) (234), composed by Paspalum pumilum, Paspalum urvillei, Paspalum pauciciliatum, Axonopus affinis and Setaria glauca. The other group is the conservation of resources, low SLA (21) and high DMC (323), composed by Paspalum notatum and Andropogon lateralis. / O presente trabalho foi realizado em área de pastagem natural no município de Restinga Sêca, RS, e teve como objetivos analisar a produtividade, qualidade, composição botânica e os atributos biológicos vegetais da pastagem natural em resposta à adubação e à disponibilidade hídrica. A adubação aumentou a produtividade da pastagem nativa. A taxa de acúmulo de MS Total tanto na área seca como na úmida, ambas adubadas foi de 102 kg/ha/dia. Nas mesmas áreas, não-adubadas, foi de 47 e 41 kg/ha/dia, respectivamente. Com relação ao material verde, a adubação também aumentou a produtividade chegando a taxas de acúmulo diária de 70 e 93 kg/ha para área seca e úmida, respectivamente, nessas áreas não-adubadas, as taxas foram de 29 e 25 kg/ha/dia. Além disso, aumentou o índice de nitrogênio e de PB nos tecidos vegetais e a quantidade de MM nas parcelas. A disponibilidade hídrica influenciou nos componentes da pastagem, quanto maior a disponibilidade de água, menor a quantidade de componentes como folha estreita, folha larga e leguminosas e maior a quantidade de FDN nos tecidos, principalmente no período de primavera. Tanto a adubação como a maior disponibilidade hídrica diminuíram a riqueza de espécies, fazendo com que algumas espécies adaptadas a essas condições dominassem a comunidade. Formaram-se dois grupos funcionais a partir dos atributos biológicos vegetais, um grupo de captura de recursos, com alta AFE (26) e baixo TMS (234), onde fazem parte as espécies Paspalum pumilum, Paspalum urvillei, Paspalum pauciciliatum, Axonopus affinis e Setaria glauca. O outro grupo é de conservação de recursos, com baixa AFE (21) e alto TMS (323), onde Paspalum notatum e Andropogon lateralis foram as espécies agrupadas.

Native to Europe and Asia, Lythrum salicaria is an invasive element on some other continents. Plants in the invaded areas are more robust, higher, and generally more successful compared to individuals in their original area. Based on my results these characteristics cannot be explained by neither higher photosynthesis, chlorophyll and carotenoid mass, nor specific leaf area.