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Seed Set, Phenology, and the Redbud Tree

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  • Sam Droege
    All: I was looking at some of the copious seed pods produced on Redbud Trees ( Celtis americana? ... Internet not handy) this summer in Kentucky and noticed
    Message 1 of 6 , Aug 20, 2010
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      All:

      I was looking at some of the copious seed pods produced on Redbud Trees (Celtis americana?  ... Internet not handy) this summer in Kentucky and noticed that it was very easy to both count the number of seeds produced directly through the pod (the pods were green) and to note the number of places in the pod that should have had a seed, but, did not.  Since the Redbud is a widely occurring understory/edge tree in at least Eastern North America and widely planted as an ornamental (not sure about the West) and short in stature (making the seed pods easy to inspect) and providing abundant nectar and pollen in the spring (see email from Mark Kraemer below);  I would propose that it has the characteristics that would make it a good candidate for monitoring both phenology and to investigate patterns and changes in seed set which should be related to pollinator abundance.  That said, I am not a pollination ecologists and am thus likely am over-simplifying the situation in regards to interpretation of rates of pollination.  However, it seems likely to me that the primary factor decreasing the seed set of Redbuds (over years) would be loss of its pollinators.  


      The following characters seem to make Redbud an appealing (at least to me) candidate for looking at geographic and habitat patterns of phenology and seed set
      • It is widely planted in urban/suburban/rural human landscapes
      • It can be readily found in the wild in some parts of North America
      • The tree is easy to identify, short in stature and the pods are low hanging
      • It is easy to identify and count the seeds (and easy to photograph them)
      • The seeds hang around for a long time
      • It blooms are highly attractive to spring bees
      • It can be used to gauge spring phenology

      I would be interested in what people think might be the interpretational issues of variations (both long and short and geographic) of seed set in Redbud.  Another issue might have to do with whether there is useful information in the absolute number of possible seeds in a pod...is this fixed or, if not, what are the possible controlling variables?

      Thanks

      sam


      Email from Mark Kraemer
       
      Here are my thoughts on using Osmia as a monitor for climate change.   I’ve worked with O. lignaria in Virginia since about 2002.  
       
      It is likely that each geographical population of bees has adapted to local climate conditions and has its own chilling and perhaps heating degree day requirements for spring emergence.   Thus, sending cohorts from one geographical region to other regions may be a problem.  For example, if bees from a colder winter climate area are sent to a warmer one and they do not get enough chilling they will have poor emergence extended over a longer period of time, similar to fruit tree bloom when not enough chill units have been accumulated.   Nest building would be extended late into the season but have nothing to do with climate change.   If bee tubes are sent out in late winter after chilling requirements are met, you still have the problem of variable and unknown temperatures during transit.  It’s best to use local bee populations if possible.  
       
      I’d use eastern red bud bloom for phenological comparisons, at least in the Eastern U.S.   I found female emergence in Virginia and North Carolina closely coincides with initial bloom of Eastern redbud.  Eastern redbud provides not just pollen but nectar early in the season when few if any other trees/shrubs are flowering.   It’s a very common forest understory tree and an ornamental found throughout most of the eastern U.S.  The vast majority of pollen (>90%) that I sampled from nest cells created in the first week was redbud (4 sites), even when the trees were not nearby the shelter boxes.   Nesting was very poor and late in one site where redbuds were not found.   I would expect first nest completions to be 7-10 days after initial redbud bloom, depending on air temps.  Some of these phenology results should appear soon in Environmental Entomology.  
       
      I’d like to know whether our observed phenological link of female emergence with Eastern redbud bloom occurs elsewhere, and the pollen composition of the early nest cells.  If this relationship is true, and because climate has changed so radically during the past few million years, I’d speculate that the bees and trees have co-evolved a very similar mechanism for coordinating their emergence/bloom through a broad range of climate change.  
       
      Mark Kraemer


      Sam Droege  sdroege@...                      
      w 301-497-5840 h 301-390-7759 fax 301-497-5624
      USGS Patuxent Wildlife Research Center
      BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD  20705
      Http://www.pwrc.usgs.gov

      Wanting Sumptuous Heavens

      No one grumbles among the oyster clans,
      And lobsters play their bone guitars all summer.
      Only we, with our opposable thumbs, want
      Heaven to be, and God to come, again.
      There is no end to our grumbling; we want
      Comfortable earth and sumptuous Heaven.
      But the heron standing on one leg in the bog
      Drinks his dark rum all day, and is content.


            - Robert Bly
    • Cowden, Nancy
      Redbud is Cercis canadensis, at least in eastern N. America; varieties/other species are found elsewhere. In addition to possible pollinator issues, redbud
      Message 2 of 6 , Aug 21, 2010
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        Redbud is Cercis canadensis, at least in eastern N. America; varieties/other species are found elsewhere.  In addition to possible pollinator issues, redbud does suffer from a number of fungal diseases, especially as it ages and/or is stressed.  As we put these trees under more stress (by planting them as street trees when they're actually forest understory plants as well as what we are doing to alter climate patterns), they are more susceptible to disease and death.  There is a graduate student at Clemson (Isaac Park) who is working on a phenology project using redbud as one of his subjects; I'll certainly pass the ideas along to him.
         
        Nancy Cowden
         

        From: beemonitoring@yahoogroups.com [beemonitoring@yahoogroups.com] On Behalf Of Sam Droege [sdroege@...]
        Sent: Friday, August 20, 2010 5:38 PM
        To: beemonitoring@yahoogroups.com; lebuhn@...; Jake Weltzin
        Subject: [beemonitoring] Seed Set, Phenology, and the Redbud Tree

         


        All:

        I was looking at some of the copious seed pods produced on Redbud Trees (Celtis americana?  ... Internet not handy) this summer in Kentucky and noticed that it was very easy to both count the number of seeds produced directly through the pod (the pods were green) and to note the number of places in the pod that should have had a seed, but, did not.  Since the Redbud is a widely occurring understory/edge tree in at least Eastern North America and widely planted as an ornamental (not sure about the West) and short in stature (making the seed pods easy to inspect) and providing abundant nectar and pollen in the spring (see email from Mark Kraemer below);  I would propose that it has the characteristics that would make it a good candidate for monitoring both phenology and to investigate patterns and changes in seed set which should be related to pollinator abundance.  That said, I am not a pollination ecologists and am thus likely am over-simplifying the situation in regards to interpretation of rates of pollination.  However, it seems likely to me that the primary factor decreasing the seed set of Redbuds (over years) would be loss of its pollinators.  


        The following characters seem to make Redbud an appealing (at least to me) candidate for looking at geographic and habitat patterns of phenology and seed set

        • It is widely planted in urban/suburban/rural human landscapes
        • It can be readily found in the wild in some parts of North America
        • The tree is easy to identify, short in stature and the pods are low hanging
        • It is easy to identify and count the seeds (and easy to photograph them)
        • The seeds hang around for a long time
        • It blooms are highly attractive to spring bees
        • It can be used to gauge spring phenology

        I would be interested in what people think might be the interpretational issues of variations (both long and short and geographic) of seed set in Redbud.  Another issue might have to do with whether there is useful information in the absolute number of possible seeds in a pod...is this fixed or, if not, what are the possible controlling variables?

        Thanks

        sam


        Email from Mark Kraemer
         
        Here are my thoughts on using Osmia as a monitor for climate change.   I’ve worked with O. lignaria in Virginia since about 2002.  
         
        It is likely that each geographical population of bees has adapted to local climate conditions and has its own chilling and perhaps heating degree day requirements for spring emergence.   Thus, sending cohorts from one geographical region to other regions may be a problem.  For example, if bees from a colder winter climate area are sent to a warmer one and they do not get enough chilling they will have poor emergence extended over a longer period of time, similar to fruit tree bloom when not enough chill units have been accumulated.   Nest building would be extended late into the season but have nothing to do with climate change.   If bee tubes are sent out in late winter after chilling requirements are met, you still have the problem of variable and unknown temperatures during transit.  It’s best to use local bee populations if possible.  
         
        I’d use eastern red bud bloom for phenological comparisons, at least in the Eastern U.S.   I found female emergence in Virginia and North Carolina closely coincides with initial bloom of Eastern redbud.  Eastern redbud provides not just pollen but nectar early in the season when few if any other trees/shrubs are flowering.   It’s a very common forest understory tree and an ornamental found throughout most of the eastern U.S.  The vast majority of pollen (>90%) that I sampled from nest cells created in the first week was redbud (4 sites), even when the trees were not nearby the shelter boxes.   Nesting was very poor and late in one site where redbuds were not found.   I would expect first nest completions to be 7-10 days after initial redbud bloom, depending on air temps.  Some of these phenology results should appear soon in Environmental Entomology.  
         
        I’d like to know whether our observed phenological link of female emergence with Eastern redbud bloom occurs elsewhere, and the pollen composition of the early nest cells.  If this relationship is true, and because climate has changed so radically during the past few million years, I’d speculate that the bees and trees have co-evolved a very similar mechanism for coordinating their emergence/bloom through a broad range of climate change.  
         
        Mark Kraemer


        Sam Droege  sdroege@...                      
        w 301-497-5840 h 301-390-7759 fax 301-497-5624
        USGS Patuxent Wildlife Research Center
        BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD  20705
        Http://www.pwrc.usgs.gov

        Wanting Sumptuous Heavens

        No one grumbles among the oyster clans,
        And lobsters play their bone guitars all summer.
        Only we, with our opposable thumbs, want
        Heaven to be, and God to come, again.
        There is no end to our grumbling; we want
        Comfortable earth and sumptuous Heaven.
        But the heron standing on one leg in the bog
        Drinks his dark rum all day, and is content.


              - Robert Bly

      • Jennifer Brower
        Dear Bee Researchers, The International Neuroscience Network Foundation supports/manages international brain-related research and also does outreach with K-12
        Message 3 of 6 , Aug 22, 2010
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          Dear Bee Researchers,

           

          The International Neuroscience Network Foundation supports/manages international brain-related research and also does outreach with K-12 students trying to interest them in careers in science, engineering, mathematics, and technology.

           

          As part of this outreach, we are running a Science Enrichment program at The SEED School of DC (http://www.seedfoundation.com/seed_schools/dc.aspx).  We bring in internationally recognized scientists to engage the students about once per month.  In addition, this year we are having an “adult science fair” or “poster session” on September 15, 2010.  If you live in the DC area and have a poster you have prepared for a conference or other event, please consider bringing the poster to the SEED School for two hours (6 – 8 pm approximately) on September 15 and sharing it with the students, grades 6 – 12.  The posters will be arranged in the gym, and the students will have a chance to wander about and ask questions of the researchers.

           

          I am reaching out to you because animals, insects, and the environment are some of the top interests of the students (in addition to gaming and robotics), and it would be fantastic to have someone, or several people, there representing bees or the environment.  Feel free to forward this request to any scientists/engineers/ mathematicians in the DC area who you think might be interested. 

           

          Volunteering at SEED can be very rewarding.  Many of the students are eager to engage and learn. I would certainly appreciate the opportunity to broaden the research presented September 15.

           

          Thanks for considering this request.  Please let me know by the end of the week  (August 27) if you are available.

           

          Best,

           

          Jennifer Brower, PhD

          Executive Vice President for Programs and Operations

          International Neuroscience Network Foundation

          500 Montgomery St. Suite 400

          Alexandria, VA 22314

          703-647-6255

          571-723-1070 (mobile)

           

           

        • Peter Bernhardt
          Dear nancy: Using redbuds as model systems in phenology studies sounds like a good idea but there are two things that trouble me. 1) What is the genetic
          Message 4 of 6 , Aug 23, 2010
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            Dear nancy:

            Using redbuds as model systems in phenology studies sounds like a good idea but there are two things that trouble me.

            1) What is the genetic difference between wild and cultivated trees?  How are redbuds propagated for the horticultural trade?  Are they grown from seed or via some mode of vegetative propagation?  Are we dealing with some sort of genetic bottleneck that will canalize the performance of the cultivars vs. the wild, self-planted trees?  You have to be careful of this, for example, when dealing with color changes in tree leaves in the autumn.  If you buy a tree or bush for Fall color it's best to select it for purchase in the fall when you can see the color change in the leaves.  What you see is what you get.  Growing it in a "nicer site" doesn't mean better color.  There's a whole range of liquidambers, for example.  In some, the leaves always turn vivd red orange.  In others the change is incomplete and the leaf is green, yellow and red in a series of blotches.

            2)  Yes, you do have those nice flat pods to check out seed set but the question is are you certain that a bump in the pod represents a fertilized developing seed?  Each pistil will contain a certain number of ovules but. in some plants, those ovules continue to develop a bit as the ovary enlarges.  It doesn't matter whether they've been fertilized or not.  Someone needs to do a little research on when you can approach a pod, count the number of bumps and be relatively assured you are counting the number of fertilized seeds. 

            Peter   

            On Sat, Aug 21, 2010 at 1:33 PM, Cowden, Nancy <Cowden@...> wrote:
             

            Redbud is Cercis canadensis, at least in eastern N. America; varieties/other species are found elsewhere.  In addition to possible pollinator issues, redbud does suffer from a number of fungal diseases, especially as it ages and/or is stressed.  As we put these trees under more stress (by planting them as street trees when they're actually forest understory plants as well as what we are doing to alter climate patterns), they are more susceptible to disease and death.  There is a graduate student at Clemson (Isaac Park) who is working on a phenology project using redbud as one of his subjects; I'll certainly pass the ideas along to him.
             
            Nancy Cowden
             

            From: beemonitoring@yahoogroups.com [beemonitoring@yahoogroups.com] On Behalf Of Sam Droege [sdroege@...]
            Sent: Friday, August 20, 2010 5:38 PM
            To: beemonitoring@yahoogroups.com; lebuhn@...; Jake Weltzin
            Subject: [beemonitoring] Seed Set, Phenology, and the Redbud Tree

             


            All:

            I was looking at some of the copious seed pods produced on Redbud Trees (Celtis americana?  ... Internet not handy) this summer in Kentucky and noticed that it was very easy to both count the number of seeds produced directly through the pod (the pods were green) and to note the number of places in the pod that should have had a seed, but, did not.  Since the Redbud is a widely occurring understory/edge tree in at least Eastern North America and widely planted as an ornamental (not sure about the West) and short in stature (making the seed pods easy to inspect) and providing abundant nectar and pollen in the spring (see email from Mark Kraemer below);  I would propose that it has the characteristics that would make it a good candidate for monitoring both phenology and to investigate patterns and changes in seed set which should be related to pollinator abundance.  That said, I am not a pollination ecologists and am thus likely am over-simplifying the situation in regards to interpretation of rates of pollination.  However, it seems likely to me that the primary factor decreasing the seed set of Redbuds (over years) would be loss of its pollinators.  


            The following characters seem to make Redbud an appealing (at least to me) candidate for looking at geographic and habitat patterns of phenology and seed set

            • It is widely planted in urban/suburban/rural human landscapes
            • It can be readily found in the wild in some parts of North America
            • The tree is easy to identify, short in stature and the pods are low hanging
            • It is easy to identify and count the seeds (and easy to photograph them)
            • The seeds hang around for a long time
            • It blooms are highly attractive to spring bees
            • It can be used to gauge spring phenology

            I would be interested in what people think might be the interpretational issues of variations (both long and short and geographic) of seed set in Redbud.  Another issue might have to do with whether there is useful information in the absolute number of possible seeds in a pod...is this fixed or, if not, what are the possible controlling variables?

            Thanks

            sam


            Email from Mark Kraemer
             
            Here are my thoughts on using Osmia as a monitor for climate change.   I’ve worked with O. lignaria in Virginia since about 2002.  
             
            It is likely that each geographical population of bees has adapted to local climate conditions and has its own chilling and perhaps heating degree day requirements for spring emergence.   Thus, sending cohorts from one geographical region to other regions may be a problem.  For example, if bees from a colder winter climate area are sent to a warmer one and they do not get enough chilling they will have poor emergence extended over a longer period of time, similar to fruit tree bloom when not enough chill units have been accumulated.   Nest building would be extended late into the season but have nothing to do with climate change.   If bee tubes are sent out in late winter after chilling requirements are met, you still have the problem of variable and unknown temperatures during transit.  It’s best to use local bee populations if possible.  
             
            I’d use eastern red bud bloom for phenological comparisons, at least in the Eastern U.S.   I found female emergence in Virginia and North Carolina closely coincides with initial bloom of Eastern redbud.  Eastern redbud provides not just pollen but nectar early in the season when few if any other trees/shrubs are flowering.   It’s a very common forest understory tree and an ornamental found throughout most of the eastern U.S.  The vast majority of pollen (>90%) that I sampled from nest cells created in the first week was redbud (4 sites), even when the trees were not nearby the shelter boxes.   Nesting was very poor and late in one site where redbuds were not found.   I would expect first nest completions to be 7-10 days after initial redbud bloom, depending on air temps.  Some of these phenology results should appear soon in Environmental Entomology.  
             
            I’d like to know whether our observed phenological link of female emergence with Eastern redbud bloom occurs elsewhere, and the pollen composition of the early nest cells.  If this relationship is true, and because climate has changed so radically during the past few million years, I’d speculate that the bees and trees have co-evolved a very similar mechanism for coordinating their emergence/bloom through a broad range of climate change.  
             
            Mark Kraemer


            Sam Droege  sdroege@...                      
            w 301-497-5840 h 301-390-7759 fax 301-497-5624
            USGS Patuxent Wildlife Research Center
            BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD  20705
            Http://www.pwrc.usgs.gov

            Wanting Sumptuous Heavens

            No one grumbles among the oyster clans,
            And lobsters play their bone guitars all summer.
            Only we, with our opposable thumbs, want
            Heaven to be, and God to come, again.
            There is no end to our grumbling; we want
            Comfortable earth and sumptuous Heaven.
            But the heron standing on one leg in the bog
            Drinks his dark rum all day, and is content.


                  - Robert Bly


          • Parker Gambino
            All, This extrapolation may be inappropriate; Regarding seed set in redbud, and using where-seeds-should-be-but-aren t in a pod to measure seed set, one
            Message 5 of 6 , Aug 23, 2010
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              All,

              This extrapolation may be inappropriate;

              Regarding seed set in redbud, and using where-seeds-should-be-but-aren't in a pod to measure seed set, one additional caution.

              In another legume tree, honey locust, there is a seed predator  (the inappropriately named bruchid beetle Amblycerus robiniae) that will destroy seeds so that some successful seed-set would be undetectable just by looking at apparent "vacancies" in the pod.  You would think that in such a common tree that the biololgy/bionomics of seed predation (OK, herbivory) would be well understood, but that is not the case.

              So be on the lookout for seed predators that might confound seed set calculations.  It matters in honey locust, but apparently there are no black locust seed predators. I am not familiar enough with redbud - it ain't where I roam too much - to know if this applies.

              Parker
            • Riddle,T Charles
              Redbud is also a legume. So there should be less maintenance (nitrogen). It seems particularly attractive to H. laboriosa, which is an important pollinator of
              Message 6 of 6 , Aug 23, 2010
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                Redbud is also a legume. So there should be less maintenance (nitrogen). It seems particularly attractive to H. laboriosa, which is an important pollinator  of wild and cultivated vaccinum in the southeast. So, it would be very useful data set for this very important bee. I have been planting them and crucifers to enhance H. laboriosa habitat for better pollination on my farm.  According to the NC State Redbud Breeding Site it is may be self incompatible. It has to be cross pollinated for seed development. Additionally, Don Orton (Coincide), Lists it as “a useful indicator plant with concise blooming Stages observable over a period of 3-4 weeks”. There is a lot of genetic variation. I have found in working with Crape myrtle that certain bees prefer certain cultivars of this plant.  From and ecological standpoint, it is also a chance to find cultivars or combinations that would have the most benefit to native bees as well as just monitoring the bees themselves. Seed development may occur as pollination occurs. This provides another opportunity to access pollinator preference and efficacy over time as well as from north to south. I do want to see cultivars developed that help pollinators.

                 

                 I have found the tree hard to collect from because they can get tall enough that netting fast flying bees can be a problem.

                 

                There are probably seed predators. I have worked with weevils and stinkbugs and usually you can tell when a seed has been eaten. A seed predator would not always eat the same seed at the same time. For example a high number of missing or small seed that should be developing at a certain time would be more probably a pollinator issue.

                From: beemonitoring@yahoogroups.com [mailto:beemonitoring@yahoogroups.com] On Behalf Of Cowden, Nancy
                Sent: Saturday, August 21, 2010 2:33 PM
                To: Sam Droege; beemonitoring@yahoogroups.com; lebuhn@...; Jake Weltzin
                Subject: RE: [beemonitoring] Seed Set, Phenology, and the Redbud Tree

                 

                 

                Redbud is Cercis canadensis, at least in eastern N. America; varieties/other species are found elsewhere.  In addition to possible pollinator issues, redbud does suffer from a number of fungal diseases, especially as it ages and/or is stressed.  As we put these trees under more stress (by planting them as street trees when they're actually forest understory plants as well as what we are doing to alter climate patterns), they are more susceptible to disease and death.  There is a graduate student at Clemson (Isaac Park) who is working on a phenology project using redbud as one of his subjects; I'll certainly pass the ideas along to him.

                 

                Nancy Cowden

                 


                From: beemonitoring@yahoogroups.com [beemonitoring@yahoogroups.com] On Behalf Of Sam Droege [sdroege@...]
                Sent: Friday, August 20, 2010 5:38 PM
                To: beemonitoring@yahoogroups.com; lebuhn@...; Jake Weltzin
                Subject: [beemonitoring] Seed Set, Phenology, and the Redbud Tree

                 


                All:

                I was looking at some of the copious seed pods produced on Redbud Trees (Celtis americana?  ... Internet not handy) this summer in Kentucky and noticed that it was very easy to both count the number of seeds produced directly through the pod (the pods were green) and to note the number of places in the pod that should have had a seed, but, did not.  Since the Redbud is a widely occurring understory/edge tree in at least Eastern North America and widely planted as an ornamental (not sure about the West) and short in stature (making the seed pods easy to inspect) and providing abundant nectar and pollen in the spring (see email from Mark Kraemer below);  I would propose that it has the characteristics that would make it a good candidate for monitoring both phenology and to investigate patterns and changes in seed set which should be related to pollinator abundance.  That said, I am not a pollination ecologists and am thus likely am over-simplifying the situation in regards to interpretation of rates of pollination.  However, it seems likely to me that the primary factor decreasing the seed set of Redbuds (over years) would be loss of its pollinators.  


                The following characters seem to make Redbud an appealing (at least to me) candidate for looking at geographic and habitat patterns of phenology and seed set

                • It is widely planted in urban/suburban/rural human landscapes
                • It can be readily found in the wild in some parts of North America
                • The tree is easy to identify, short in stature and the pods are low hanging
                • It is easy to identify and count the seeds (and easy to photograph them)
                • The seeds hang around for a long time
                • It blooms are highly attractive to spring bees
                • It can be used to gauge spring phenology


                I would be interested in what people think might be the interpretational issues of variations (both long and short and geographic) of seed set in Redbud.  Another issue might have to do with whether there is useful information in the absolute number of possible seeds in a pod...is this fixed or, if not, what are the possible controlling variables?

                Thanks

                sam


                Email from Mark Kraemer
                 
                Here are my thoughts on using Osmia as a monitor for climate change.   I’ve worked with O. lignaria in Virginia since about 2002.  
                 
                It is likely that each geographical population of bees has adapted to local climate conditions and has its own chilling and perhaps heating degree day requirements for spring emergence.   Thus, sending cohorts from one geographical region to other regions may be a problem.  For example, if bees from a colder winter climate area are sent to a warmer one and they do not get enough chilling they will have poor emergence extended over a longer period of time, similar to fruit tree bloom when not enough chill units have been accumulated.   Nest building would be extended late into the season but have nothing to do with climate change.   If bee tubes are sent out in late winter after chilling requirements are met, you still have the problem of variable and unknown temperatures during transit.  It’s best to use local bee populations if possible.  
                 
                I’d use eastern red bud bloom for phenological comparisons, at least in the Eastern U.S.   I found female emergence in Virginia and North Carolina closely coincides with initial bloom of Eastern redbud.  Eastern redbud provides not just pollen but nectar early in the season when few if any other trees/shrubs are flowering.   It’s a very common forest understory tree and an ornamental found throughout most of the eastern U.S.  The vast majority of pollen (>90%) that I sampled from nest cells created in the first week was redbud (4 sites), even when the trees were not nearby the shelter boxes.   Nesting was very poor and late in one site where redbuds were not found.   I would expect first nest completions to be 7-10 days after initial redbud bloom, depending on air temps.  Some of these phenology results should appear soon in Environmental Entomology.  
                 
                I’d like to know whether our observed phenological link of female emergence with Eastern redbud bloom occurs elsewhere, and the pollen composition of the early nest cells.  If this relationship is true, and because climate has changed so radically during the past few million years, I’d speculate that the bees and trees have co-evolved a very similar mechanism for coordinating their emergence/bloom through a broad range of climate change.  
                 
                Mark Kraemer


                Sam Droege  sdroege@...                      
                w 301-497-5840 h 301-390-7759 fax 301-497-5624
                USGS Patuxent Wildlife Research Center
                BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD  20705
                Http://www.pwrc.usgs.gov

                Wanting Sumptuous Heavens

                No one grumbles among the oyster clans,
                And lobsters play their bone guitars all summer.
                Only we, with our opposable thumbs, want
                Heaven to be, and God to come, again.
                There is no end to our grumbling; we want
                Comfortable earth and sumptuous Heaven.
                But the heron standing on one leg in the bog
                Drinks his dark rum all day, and is content.


                      - Robert Bly

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