Introduction

This document summarises the Round 1 - Initial estimates of the Fine Scale Metrics for ACT Urban Habitat and Connectivity Project expert elicitation for insect pollinators - namely native bees and butterflies using the IDEA protocol (refer to Hemming et al. 2018 “A practical guide to structured expert elicitation using the IDEA protocol” and Burgman 2016 “Trusting Judgements: How to get the best out of experts”).

For each question asked in the expert elicitation, we have summarised the results. All responses from the expert elicitation remain anonymous, with visualised experts estimates being denoted by a number on the x- axis. Below each visualised estimate, the comments provided by experts are collated.

The intervals displayed are for a Three-Step Elicitation.

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Structural habitat metrics

The next series of visualisations relate to structural habitat metrics.

Structural habitat metrics describe the finer scale structural elements of a species’ habitat and how the various features are arranged in space. For example, some species may need access to bare ground for nesting to be able to successfully occupy a habitat patch. This would be a structural requirement.

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Preferred % cover of bare ground

Access to bare ground may relate to things such as nesting sites (for burrowing or fossorial species) or spaces to hunt. What percentage of ground needs to be bare ground for an area to be preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 10 5.0 70 This is based on the requirements of ground nesting bees and personal observations in the field. 50 Insect_pollinators percent_ground Initial
4 10 1.0 30 Around 70% of bee species nest predominatly in the ground, so it is an important nesting resource. However, most species will find suitable sites in the soils among plants, rocks, logs, grass and other structures. There are some species that prefer bare ground, so the retention/creation of at least some patches of bare soil would be appropriate. 70 Insect_pollinators percent_ground Initial
18 20 5.0 25 My confidence level is not very high because it seems slightly unreasonable to simply look at the ratio of bare ground present in any given area. The site composition is more important in my opinion. What soil is it (type, granule size, level of disturbance)? What is next to that bare soil: plants, parking lots, houses, …? Also, I find it important to distinguish if we are talking about a “nesting habitat”, a “foraging habitat” or something that can provide both. Smaller areas often cannot provide all the things needed for an animal. However, bees are relatively mobile species and can therefore, choose a nesting habitat that is structurally (but not functionally!) isolated from the foraging habitat. 50 Insect_pollinators percent_ground Initial
24 15 10.0 50 Bare ground is required for some ground-nesting species 20 Insect_pollinators percent_ground Initial
30 8 5.0 20 too much bare ground a problem because of what it suggests about likely abundance of flowering plants. Too little would disadvantage soil nesters (ie most species) 80 Insect_pollinators percent_ground Initial
Aggregated 13 5.2 39 NA 54 Insect_pollinators percent_ground Aggregated

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Preferred % cover of grass thatch (dead, unattached grass)

Grass thatch is the layer of dead plant material that develops between the zone of green vegetation and the soil surface. We consider dead grass to be thatch once it is no longer attached to the parent plant. Grass thatch can be beneficial for some species (e.g. providing habitat for nesting) but detrimental for other species (e.g. obstructing movement). What percentage cover of grass thatch is consistent with an area being preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 30 1.0 80 Grass can be used not only for nesting material but as a food resource. I have estimated on the lower end due to presumably the rest of the habitat being compromised of flowering shrubs/ trees. 60 Insect_pollinators percent_thatch Initial
4 0 0.0 0 I don’t believe dead grass plays any role in the life cycle or ecology of natvie bees. They do not feed on it, or build nests with grass. Other insect pollinators may use it for these purposes. 50 Insect_pollinators percent_thatch Initial
18 0 0.0 0 I think this variable is not important for (most) insect pollinators. 100 Insect_pollinators percent_thatch Initial
24 0 0.0 0 I’m not sure the extent to which dead grass would be important (perhaps as sites for male resting aggregations- but these could plausibly occur elsewhere? And this seems to refer to unattached grass anyway, which I don’t think would be used) 5 Insect_pollinators percent_thatch Initial
30 0 0.0 10 not aware of any benefits (though perhaps there are species that collect dead grass for some nesting? Like leaf cutters?? 80 Insect_pollinators percent_thatch Initial
Aggregated 6 0.2 18 NA 59 Insect_pollinators percent_thatch Aggregated

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Preferred depth of grass thatch (cm)

The definition of grass thatch here is consistent with the previous question, however this question focuses on the depth of the grass thatch layer. What depth of grass thatch is consistent with preferred habitat for this taxon group? Consider the most appropriate depth of grass thatch in centimetres.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 0 0 0 I don’t think the depth of grass is an important factor 90 Insect_pollinators thatch_depth Initial
4 0 0 0 I don’t believe depth of grass thatch is important for this group 50 Insect_pollinators thatch_depth Initial
18 0 0 0 I think this variable is not relevant for (most) insect pollinators. 100 Insect_pollinators thatch_depth Initial
24 0 0 0 I don’t think grass thatch depth is likely to be important (but I am not confident about this opinion ) 10 Insect_pollinators thatch_depth Initial
30 0 0 0 as previous 80 Insect_pollinators thatch_depth Initial
Aggregated 0 0 0 NA 66 Insect_pollinators thatch_depth Aggregated

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Preferred % cover of leaf litter

Some species require access to leaf litter for food resources (e.g. arthropods and other invertebrate living in the leaf litter) or may require leaf litter as habitat refugia (for burrowing or fossorial species). What percentage of cover of leaf litter is consistent with preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 0 0 0 I don’t believe this is an important factor for native bees. 90 Insect_pollinators percent_litter Initial
4 30 10 60 Leaf litter is important for providing shade/cover for nest sites, improivng soil quality and nutrition for flowering plant growth (important food source) 70 Insect_pollinators percent_litter Initial
18 0 0 0 I am very confident that leaf litter is of no importance for (most) insect pollinators. It is however an important resource for other, particularly ground-dwelling insects. 90 Insect_pollinators percent_litter Initial
24 25 5 50 Some species might nest beneath leaf litter (but ubncloear if this is preferred) See: Houston, T.F., 2020. On the remarkable nesting biology of an Australian bee in the genus Trichocolletes Cockerell (Hymenoptera: Colletidae). Austral Entomology, 59(3), pp.593-601. 5 Insect_pollinators percent_litter Initial
30 0 0 0 i can’t think of any direct benefits of leaf litter for pollinators, even though I think of leaf litter as a component of a health patch of veg. Perhaps an interaction with availability of soil nesting resources? 50 Insect_pollinators percent_litter Initial
Aggregated 11 3 22 NA 61 Insect_pollinators percent_litter Aggregated

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Preferred % grass cover (all grasses)

The percentage cover of grass might be important for some species based on refugia sites or food resources. What percentage of grass cover is consistent with preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 50 1.0 95 A mix of grass and bare earth are important for a range of different native bees as they use the grass for nesting materials, roosting and as a food resource. 60 Insect_pollinators percent_grass Initial
4 10 0.0 40 Some species will feed on grass pollen, so this can be a useful supplement to other flowering plants. High quality grasslands also include many flowering plants, some of which have mutualisms with pollinator species.. 60 Insect_pollinators percent_grass Initial
18 20 5.0 25 “Grass” needs to be defined. I think lawn and turf are not really needed for an insect pollinator but it does “soften” the harsh urban environment and might even offer nesting habitat. A GRASSLAND, however, can be seen as a very important habitat (nesting and foraging) for most insect pollinators. Particularly native grasslands with high species richness of grasses and forbs should be encouraged. Even smallest patches, such as road verges, will be highly beneficial. 75 Insect_pollinators percent_grass Initial
24 10 0.0 50 Might be used as roosting sites, but unclear if necessary the extent to which grass is preferred See: Kubiak, P.J., 2013. Sleeping aggregations of bees in relation to the risk of fire at their roosting sites in a forested, suburban landscape in eastern Australia. Victorian Naturalist, The, 130(1), pp.22-36. 1 Insect_pollinators percent_grass Initial
30 0 0.0 0 not aware of any direct benefits of grasses (unless some might be nesting habitat for some stem nesting bees?) 60 Insect_pollinators percent_grass Initial
Aggregated 18 1.2 42 NA 51 Insect_pollinators percent_grass Aggregated

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Preferred % invasive grass cover (e.g. Wild oats, Chilean Needle Grass, Serrated Tussock, African Love Grass)

It is possible/likely that a component of total grass cover in the urban space will be comprised of highly invasive grass species. These species can monopolise grassy areas and impact on ground layer structure and function for many species. What is the percentage cover of invasive grasses which is consistent with preferred habitat for this taxon group? This metric might be used to trigger invasive plant management regimes, or identify priority areas for restoration, as some examples.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 50 1.0 90 I don’t think it would make a difference if the grass was introduced if the resource the bees were harvesting was for nesting material but it may make a difference if they are harvesting it as a food resource. 70 Insect_pollinators percent_invasive Initial
4 10 0.0 40 I don’t believe pollinating insects would be particuallry constrained by invasive grasses, other than when they reach high levels and exclude other flowering resources. That said, the fewer invasive grasses the better, to promote high qulaity pollinator habitat. 50 Insect_pollinators percent_invasive Initial
18 0 0.0 0 Invasive grass species per se are not a relevant variable for insect pollinators. Grasses in general do not have much benefit for insect pollinators. Native grasslands in small and big patches should be integrated and managed in a way to prevent invasion of any kind. 90 Insect_pollinators percent_invasive Initial
24 0 0.0 50 Not sure about this. Do these grasses crowd out better foraging resources? 5 Insect_pollinators percent_invasive Initial
30 0 0.0 30 presence of invasive grasses likely correlated with loss of forbs that might be important floral resources 60 Insect_pollinators percent_invasive Initial
Aggregated 12 0.2 42 NA 55 Insect_pollinators percent_invasive Aggregated

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Preferred % native forb cover

Native forbs include any flowering ground-layer plant, that is not a grass, sedge or rush. They may provide habitat structure or food resources. What percentage cover of native forbs is consistent with preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 80 10 100 Best estimate reflects that ideally there would be a mix of grass and bare earth in addition to native forbs. 70 Insect_pollinators percent_forb Initial
4 60 10 100 Native forb cover is very important as a pollinator food source, particulalry if it is close to nest sites and other resources. While many species can travel some distance to find these plants, the more they are in the landscape, and the better connected with nesting resources, the greater the insect polinator diversity will be. 70 Insect_pollinators percent_forb Initial
18 70 50 100 Very important resource for all insect pollinators. However, I think the total patch size, the number of patches in the landscape and the plant diversity (species and traits) are far more important than the % cover. 90 Insect_pollinators percent_forb Initial
24 50 10 100 Not sure the extent to which native forbs are required- this would depend on species-specific foraging needs 10 Insect_pollinators percent_forb Initial
30 50 20 80 native forbs will be important floral resources. Only reason to set a max is that 100% forb covers suggests no shrubs, which would be a negative 50 Insect_pollinators percent_forb Initial
Aggregated 62 20 96 NA 58 Insect_pollinators percent_forb Aggregated

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Preferred % exotic broad leaf cover (e.g. thistles)

Exotic broad leaf plant species (such as thistles or pigweed) make up the majority of the non-native ground layer plants which are not grasses, sedges or rushes. They may exclude native vegetation from growing in the ground layer or alter habitat structure. What percentage cover of exotic broad leaf plants is consistent with preferred habitat for this taxon group?

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 0 0 95 I find these questions tricky as it kind of implies that I am advocating for introduced species to be included in the ‘best’ case scenario. Its possible that native bees can live within areas with exotic brad leaf plants but I still struggle to include them in the ‘best’ case scenario. 60 Insect_pollinators percent_broad Initial
4 10 0 60 Some insect pollinators will regularly visit weedy flowering species for food. However, greater health benefit comes from a diversity of floral resources, so exotic weed cover should be kept low to promote better floral diversity. 70 Insect_pollinators percent_broad Initial
18 20 0 30 High coverage of ground-covering succulents should be avoided. particularly well-watered patches will increase the establishment of non-native weeds in their gaps (Unpublished research by a colleague). 80 Insect_pollinators percent_broad Initial
24 5 0 75 This is likely dependent on the specific exotic species and the specific bee species. 20 Insect_pollinators percent_broad Initial
30 0 0 20 although native bees will sometimes forage on exotic forbs, the presence of exotic forbs comes at the cost of native forbs. The rarer bees are likely to be associated with native forbs 80 Insect_pollinators percent_broad Initial
Aggregated 7 0 56 NA 62 Insect_pollinators percent_broad Aggregated

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Preferred total length of coarse woody debris (>10cm diameter incl. snags, stumps)

Coarse woody debris (CWD) refers to fallen dead trees and the remains of large branches on the ground in forests, grasslands and in aquatic ecosystems. Here we define CWD as being greater than 10 cm in diameter and including snags (aquatic) and tree stumps. CWD provides structure and refugia within a terrestrial habitat and changes physical and hydraulic properties in aquatic systems. CWD needs to be considered when managing forests for biodiversity but also for managing fire risk. What is the preferred total length of coarse woody debris required in an area to be preferred habitat for this taxon group? Consider the total length in metres in a one-hectare patch.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 0 0.0 0 Depth of course woody debris is important for cavity nesting bees but I am struggling to find a reason for why length may be important. 90 Insect_pollinators cwd_length Initial
4 50 15.0 100 Some pollinators will use woody debris for nesting, perching etc. For wood nesting species, 15cm is generally considered the mimimum length to ensure effective rearing (both male and females can emerge). 40 Insect_pollinators cwd_length Initial
18 5 2.0 15 most native bees are ground-nesting, however, the provision of CWD will provide nesting opportunities for the captivity-nesting pollinators. I think that we should take the target species’ moving or home range into consideration, which is not necessarily as big as a hectare. There should be CWD available within a pollinator’s home range, for bees that can be as small as 31m (Homalictus shpecodoides). 90 Insect_pollinators cwd_length Initial
24 20 10.0 100 I can’t visualise this metric so am unable to provide a good estimate 1 Insect_pollinators cwd_length Initial
30 5 2.0 10 some native bees use holes in woody debris for nesting. Volume of wood probably matters less than the particular qualities of it (ie does it have bore holes?) 50 Insect_pollinators cwd_length Initial
Aggregated 16 5.8 45 NA 54 Insect_pollinators cwd_length Aggregated

Preferred number of hollow bearing trees

A hollow-bearing tree is a tree where the trunk or limbs contain hollows, holes or cavities. Hollows are particularly important for providing shelter and nesting sites for fauna, with some species being hollow dependant. What is the preferred number of hollow bearing trees required for the habitat to be suitable for this taxon group? Consider the minimum number of hollow bearing trees in a one-hectare patch.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 0 0 0 Not relevant for native bees 90 Insect_pollinators no_hbtrees Initial
4 30 0 60 While insect pollinators don’t use hollows per se, older hollow bearing trees may also contain smaller cavities or beetle holes that can be utilised by wood nesting species. They may also provide more abundant food resources (e.g. eucalypt flowering) than smaller trees. 60 Insect_pollinators no_hbtrees Initial
18 0 0 0 hollows are frequently occupied by feral honeybees (Apis mellifera) which might act as competitors for native insect pollinators. In fact, feral bee hives should be relocated so it can be occupied by birds and remove honey bees as potential competitor for food resources. 100 Insect_pollinators no_hbtrees Initial
24 0 0 10 I don’t think this variable will be important (no stingless bees or other native cavity nesters in ACT?) 20 Insect_pollinators no_hbtrees Initial
30 0 0 0 no native bees in canberra use tree hollows. Feral honeybees do. Dead trees can have other benefits though (see CWD answer) 80 Insect_pollinators no_hbtrees Initial
Aggregated 6 0 14 NA 70 Insect_pollinators no_hbtrees Aggregated

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Preferred % cover of floral resources

Floral resources refer to flowering plants which might provide food resources throughout the entire forest column (i.e. ground layer to canopy). What is the preferred percentage cover of floral resources in an area at any one time which is associated with preferred habitat for this taxon group? You might consider the percentage cover across a one-hectare patch if it helps, or another scale if that makes more sense to you. We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 40 10 100 My lower estimate is based on the idea that this would be provided throughout the year. From field studies I have seen quite a low percent flower cover support a high abundance and diversity of bees but obviously this depends on the quantity/quality of resource offered. 70 Insect_pollinators percent_floral Initial
4 50 20 100 Floral resources are very important for pollinators as their primary (and often only) food source. So generally more flowers = more pollinators (and possibly greater diversity). Feral and managed honeybees may interact in ways we don’t yet understand at different concentrations of flowering though. 60 Insect_pollinators percent_floral Initial
18 40 20 60 Flowering species which differ in colour, shape, life form, nativeness, should be available at any time of the year across all seasons to provide enough food resources to a variety of native insect pollinators. 90 Insect_pollinators percent_floral Initial
24 80 25 100 I’m not sure there is a point where there are too many flowers? Would alos depend on the specific flower species 25 Insect_pollinators percent_floral Initial
30 100 60 100 floral resources are key to bees. I cant really see how you could have “too much”, except perhaps the implication that this might mean no bare ground for soil nesters 90 Insect_pollinators percent_floral Initial
Aggregated 62 27 92 NA 67 Insect_pollinators percent_floral Aggregated

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Preferred number of flowering species (floral resource diversity)

A diversity of flowering plants throughout the entire forest column (i.e. ground layer to canopy) provides food resources across time and space. What is the preferred number of flowering species in an area at any one time for the habitat to be preferred for this taxon group? Consider the preferred number of flowering species across a one-hectare patch. We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 100 5 500 I think its probably the case that the more the better when it comes to the number of flowering species. There is therefore I a higher chance of a food resource/ nesting resource and potential habitat for native bees to use. 70 Insect_pollinators min_flower_sp Initial
4 20 1 40 Floral diversity is very important for pollinator diversity, and to aid health of individuals. While species can survive on a single floral resource, this can only really sustain an individual for a short period, and is unlikely to sustain many different species. Really, to increase diversity of species and the health of those species, any number of flowering plants could be included into restoration activities - the more the better. 60 Insect_pollinators min_flower_sp Initial
18 50 20 100 Species should offer a variety of flowering season, colour, shape, life form. And come from a variety of plant families as well. 90 Insect_pollinators min_flower_sp Initial
24 100 20 200 As with the previous question, I don’t know if there is a point where there is too much diversity? I imagine it woudl depend on the distribution- too many tiny patches of many different species might pose cognitive challenges to bees (but probably not?) 20 Insect_pollinators min_flower_sp Initial
30 20 10 100 Too few species and you will have very poor pollinator diversity. I cant think of a realistic maximum! What really matters is how diverse the species are in terms of phylogeny and flowering phenology 50 Insect_pollinators min_flower_sp Initial
Aggregated 58 11 188 NA 58 Insect_pollinators min_flower_sp Aggregated

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Minimum temporal availability of floral resources

A diversity of flowering plants throughout the entire forest column (i.e. ground layer to canopy) provides food and other resources across time. What is the minimum temporal availability of floral resources in an area for the habitat to be suitable for this taxon group, in terms of the number of months per year? (e.g. a score of 6 would indicate that flowering plants were available for at least 6 months of the year, although not necessarily continuously). We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 12.0 12.0 12 This is largely based on the need to have something flowering at all times as there are likely to be periods where even if there are floral resources available they may not be suitable or of sufficient quality and therefore may a shortage of food. 90 Insect_pollinators temp_floral Initial
4 10.0 5.0 12 Year-round floral resources are important to cater for different pollinator species. Individuals may only be active for a few weeks before reproducing and dying, however different species emerge at different times thorughout the year and may have more than one breeding event. The key times for floral resources to be available are spring and early summer, however having flowering for at least 10 months of the year (the very coldest months are likely to have little activitiy) would be recommended. 70 Insect_pollinators temp_floral Initial
18 10.0 8.0 12 Ideally, floral resources will be available throughout the entire year. However, the vast majority of insect pollinators hybernate in the colder months. It is important to offer them suitable floral resources in the end of winter when the first species emerge from hibernation. 90 Insect_pollinators temp_floral Initial
24 12.0 11.0 12 I found sightings of native bees in 11/12 months in ACT (based on iNaturalist records, so not high confidence). If we include hoverflies (which occur year-round), than floral resources are required 12/12 months of the year. 40 Insect_pollinators temp_floral Initial
30 5.0 2.0 8 most species are not active through the coldest months, so flowering in winter months is not so important 80 Insect_pollinators temp_floral Initial
Aggregated 9.8 7.6 11 NA 74 Insect_pollinators temp_floral Aggregated

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Preferred % cover of shrub layer (0.5-3m height)

The mid-storey or shrub layer provides structure for nesting, refugia from predators and food resources for many species. This could be related to the amount or complexity of structure the species group prefers or is tolerant of in its preferred habitat, or some other feature of the species groups’ general biology or life history. This metric considers the percentage cover across a one hectare patch.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 60 10 90 I think a mix of flowering forbs and shrubs is as well as bare earth are probably best and would provide adequate habitat and resources. 70 Insect_pollinators percent_shrub Initial
4 40 10 80 A range of different flowering resources are important, and structurally, shrubs are important habitat for feeding, hiding, perching and to provide shade and shelter for nests 60 Insect_pollinators percent_shrub Initial
18 20 5 40 While shrubs are important for shelter and habitat complexity, they should also contribute as a food resource. particularly native shrubs that have flowers attracting native insects and fruits attracting native birds/mammals/marsupials will be a good solution. 75 Insect_pollinators percent_shrub Initial
24 15 10 25 Shrubs can provide nesting rsources 5 Insect_pollinators percent_shrub Initial
30 40 10 70 in general expect a mix of shrubs and forbs to be best. Total domination by one or the other layer would probably reduce diversity 60 Insect_pollinators percent_shrub Initial
Aggregated 35 9 61 NA 54 Insect_pollinators percent_shrub Aggregated

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Preferred % tree canopy cover (per ha)

The tree canopy provides structure (such as shade), habitat and resources for a range of species. Tree canopy cover may influence how a species can move from one tree to the next without going along the ground, or some other feature of the taxon groups’ general biology or life history. This metric accounts for the availability of canopy cover from exotic and native tree species in the environment, as well as both young and mature trees (> 3m height). Consider the percentage cover across one hectare patch.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 20 0 90 You most likely don’t want a full canopy as many native bees generally prefer to forage in a sunny position and use UV floral guides to orient and fin food. On the other hand some of the best and most bountiful floral resources come from trees so somewhere in the middle is probably best. 60 Insect_pollinators percent_canopy Initial
4 60 20 100 Canopy cover (primarily of Eucalypts) is very importnat. These are often abundant food sources for pollonators and provide suitable nest sites. Many bee species for instance will forage more on Eucalypts than any other group of plants, while some will only feed on plants from the Myrtaceae family. Canopy cover also provides structural connectivity to aid movement and dispersal. 60 Insect_pollinators percent_canopy Initial
18 30 5 50 The entire landscape composition is important. A given patch of land should offer a variety of land covers, providing resources for many different insect pollinators. Some uniquely use trees, some uniquely use grasslands, most however use something in between (a bit of each). I therefore suggest something like this: 30% canopy, 10% shrubs, 40% grasslands, 10% open unvegetated area for nesting, 10% structures for human use. 80 Insect_pollinators percent_canopy Initial
24 20 5 90 Species specific and probably depends on which flowering resources are available (eg. are the trees in flower?) 5 Insect_pollinators percent_canopy Initial
30 20 10 40 tree cover will be less important than forbs and shrubs, but a few trees present will add more floral species to the mix, which is good 60 Insect_pollinators percent_canopy Initial
Aggregated 30 8 74 NA 53 Insect_pollinators percent_canopy Aggregated

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Physical chemical properties

The next series of visualisations relate to physical chemical properties.

Physical chemical properties mostly relate to the aquatic environments or soil.

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Preferred soil moisture content

Soil moisture content is the total amount of water, including the water vapor, in the soil. Soil moisture influences the vegetation species present and can affect burrowing and feeding activity of some fauna. This metric seeks to determine the preferred soil moisture content for the taxon group.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 5 0.0 40 I am not really sure about soil moisture or how to judge it but I would imagine that they prefer it to be more on the dry side than too wet or waterlogged. Nests will become mouldy or they wont be able to build the nests at all. 40.0 Insect_pollinators soil_moisture Initial
4 0 0.0 0 I don’t know if/how this important for bee nesting for instance, so have opted not to answer 1.0 Insect_pollinators soil_moisture Initial
18 0 0.0 0 this topic cannot be covered by my expertise and I do not like to be too presumptuous. 1.0 Insect_pollinators soil_moisture Initial
24 30 3.0 80 Likely species dependent. Couldn’t find much info for Australian species. My estimates are based on numbers in : Antoine, Cécile M., and Jessica RK Forrest. “Nesting habitat of ground‐nesting bees: a review.” Ecological Entomology 46, no. 2 (2021): 143-159. 5.0 Insect_pollinators soil_moisture Initial
30 0 0.0 0 i have no knowledge of how this will matter (beyond that we want the plants to be alive!) 1.0 Insect_pollinators soil_moisture Initial
Aggregated 7 0.6 24 NA 9.6 Insect_pollinators soil_moisture Aggregated

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Habitat function and risk management

The next series of visualisations relate to habitat function and risk management.

This section asks questions regarding habitat function and risk management for your selected taxon group.

These metrics describe what sorts of risks need to be managed within habitat areas to retain habitat function. The responses to these questions will aid in the identification, design and restoration of habitat patches and connectivity corridors in the urban space, provide an evidence base for policy decision making, and set thresholds for management intervention.

The answers to these questions will help us to understand how far apart different patches of habitat can be whilst still being connected for a taxon group, as well as what the aspirations should be in terms of the total extent of connected habitat at the landscape or regional scale to facilitate typical dispersal patterns for the species. Below, we ask you to provide your upper, lower and best estimates for a range of metrics related to patch size and movement behaviour.

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Minimum tolerable fire interval

Fire can impact on habitat suitability either by influencing core habitat structural elements (such as ground and mid-storey complexity) or by causing direct mortality to individuals or populations. This metric seeks to determine the minimum tolerable fire interval (assuming low-moderate intensity burns on a patchy sub-hectare scale) before there is an impact on resident species. The assumption is that fire is applied during the active period for the species (e.g. during daylight hours on a warm day for grassland reptiles). We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 10 1.0 100 I really don’t know what the answer is here. I would imagine what ever is ‘normal’ for the system might be also appropriate for the bees. Based on our research after a sever fire we are still finding native bees in the system although presumably this has a lot to do with the floral resources available after a burn, fire history, severity as well as the patchiness of the burn. 20 Insect_pollinators fire_interval Initial
4 12 3.0 56 Fire is a tricky metric for insect pollinators as it can act to both the benefit and detriment of species. Immediate impacts could be loss of nest sites and floral resources and death of individuals. Longer term effects could be delayed/unavailable flowering, limited dispersal avenues. However, some flowering plant species may respond positively to fire, increasing flower production or recruitment of species. Large extensive fires will likely have greater impact than benefit. 50 Insect_pollinators fire_interval Initial
18 0 0.0 0 this topic cannot be covered by my expertise and I do not like to be too presumptuous. 1 Insect_pollinators fire_interval Initial
24 12 6.0 24 Species specific. I imagine ground nesters might be resistant to fire impacts, whereas twig nesters might be more heavily impacted. Also depends on fire intensity and how long it takes for flowers to return posy burn 1 Insect_pollinators fire_interval Initial
30 100 24.0 240 very uncertain on this. Answer reflects that annual or more frequent fire could damage populations but absence of fire might reduce floral diversity 10 Insect_pollinators fire_interval Initial
Aggregated 27 6.8 84 NA 16 Insect_pollinators fire_interval Aggregated

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Minimum tolerable mowing intervals

Mowing can impact on habitat suitability either by influencing core habitat structural elements (such as ground storey complexity) or by causing direct mortality to individuals or populations. This metric seeks to determine the minimum tolerable mowing interval (assuming mowing to 5cm height using a ride-on slasher) before there is an impact on resident species. The assumption is that mowing is undertaken during the active period for the species (e.g. during daylight hours on a warm day for grassland reptiles) and covers all accessible areas (i.e. leaves patches around fence posts and sign bases). It is also assumed that there are limited other ground-layer disturbance mechanisms (e.g. herbivore grazing) taking place in mown areas. We encourage you to leave additional notes around any additional considerations you feel are necessary to support your response.

Expert Best Lower Upper Comments Confidence Taxon Variable Group2
3 12.0 0.25 12.0 Mowing can remove floral resources available but other than that I can’t think of another possible impact. 60 Insect_pollinators mowing_interval Initial
4 1.0 0.50 12.0 Mowing can reduce flowering, but often this is of introduced weedy species. Low to moderate mowing frequency would be unlikely to affect pollinators too much, particulalry if shrub and canopy flowering is available, however very frequent mowing or mowing of sensitve flora could deplete important floral resources. 60 Insect_pollinators mowing_interval Initial
18 0.0 0.00 0.0 this topic cannot be covered by my expertise and I do not like to be too presumptuous. 1 Insect_pollinators mowing_interval Initial
24 6.0 1.00 12.0 Depends on species- mowing likely detrimental to ground nesters, but not for others. Also depends on whether other flower resources re available beyond the mown area 2 Insect_pollinators mowing_interval Initial
30 0.0 0.00 0.0 not sure how to answer this - it all depends on how mowing interacts with flowering, and that will depend on the plant species 1 Insect_pollinators mowing_interval Initial
Aggregated 3.8 0.35 7.2 NA 25 Insect_pollinators mowing_interval Aggregated

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