USA National Phenology Network

What is a representative location?

Where possible, sites should be relatively flat or gently sloping, and neither excessively dry nor wet for your area. Avoid steep, south-facing or north-facing slopes, and areas that are subject to drifting snow or excessive winds. Avoid locations where plants are given supplemental water or fertilizer. In forested areas, the site should reflect the overall canopy composition and stature/size. However, we welcome all observations, so if your site seems outside of these guidelines, just be sure to record these unusual characteristics in the comments section of the site registration form.

How do I choose an appropriate size for my site?

The size of your sampling site will depend on the scale of your landscape and the proximity of the individuals being observed. Aim to strike a balance between efficiency of observation across the site with the time you have available, and not having the individuals being observed too close together (see How many individuals of the same species should I monitor?). Your monitoring locations should be divided into different sites if their habitats are obviously different.

Do I need permission to make observations on public land?

For public parks or other public lands, you should get permission from the appropriate department of the federal government, the state, or the municipality that has responsibility for the property. Land managers often issue hard-copy permits for land access, which will help guarantee your study.

How do I identify my plant species?

Correct plant identification is important when reporting your observations to the USA-NPN. Before you submit observations for a plant make sure you have identified it as one of the species listed on the USA-NPN list. You may keep track of observations on a datasheet until you have confirmed the plants identity (see Can I start monitoring a plant if I am unsure which species it is?). The USA-NPN is not staffed to make site visits or to identify plants from photographs, but we will be adding more information to the species profiles to help with identification. In the meantime there are resources that you can use to help you identify plants of interest.

If you are a beginner to plant identification, you may find that there are many local resources to help you. Often communities have local naturalists and expert gardeners that can provide assistance. The places you may find this help could include: a local native plant society, gardening societies, a master gardener program, state or county cooperative extension office, the botany department of a local college, or professional botanists with state or federal land management agency. Also botanical guides may exist for your state or even your local area that provide useful information.

If you have one nearby, the best place to go is an herbarium where trained botanists offer assistance in identifying plants. A worldwide listing of herbaria is available through the New York Botanical Garden. Search their online database to locate an herbarium in your town or within your state.

Once you identify a person that can help you, you may need to take them a sample from your plant. Do not take a single leaf or flower, but rather break off a twig, stem, or grass blade that includes the point where the leaves and/or flowers are attached. However, do not break off such a large portion of a plant that you are likely to destroy the individual, especially if the plant seems like it might be rare and there are very few other individuals nearby.

If you do have some idea of what species the plant is and want more information or confirmation, the internet is a good place to start. USDA PLANTS is a database that provides many resources if you know a plants common or scientific name. You might also want to try out some of the online plant identification guides. For trees, check out the guide with the Arbor Day Foundation. Or you may want to check out the online guides for all plant types at Discover Life (http://www.discoverlife.org/mp/20q).

Can I start monitoring a plant if I am unsure which species it is?

Yes, you can keep track of observations on a field datasheet, but please do not enter observation data online for a plant until you have identified the species with reasonable confidence. When a plant is dormant, it may be difficult to tell which species it is, but you probably have a good idea about whether it is an herb, a grass, or a deciduous tree. The phenophase definitions within these broad groups are fairly standard, so we recommend you find a similar species and use the datasheet and phenophases for that species (see some choices below).

Once the plant has produced leaves or flowers such that you can identify it, please check the phenophases for that species to make sure they are consistent with what you had been looking for. If so, you can enter all the data online. If not, please do not enter the old observations and just start with the date when you were using the correct phenophase definitions. If it turns out your plant is not on the USA-NPN plant list, please see What can I do if the plant I would like to monitor is not on the USA-NPN species list?

What can I do if the plant I would like to monitor is not on the USA-NPN species list?

The USA-NPN regional species list includes plants of interest due to their dominance, conservation value, association with health issues (such as allergens), or importance to ecosystem services such as food supply. We are working on expanding the list of plants and welcome your suggestions for additions. However, as we make additions to the list, we will not be able to develop the species profiles and monitoring instructions for suggested new plants until later this year or in 2010.

In the meantime, if you would like to start monitoring a plant not currently on the USA-NPN list, you can use the Project BudBurst monitoring site and protocols. Project Budburst is the general education and outreach program for the USA-NPN and all plant species observations are accepted. The data is incorporated into the same USA-NPN database and if the plant species you have suggested is added to the USA-NPN regional species list in the future, you can switch to using the new monitoring protocols at that time.

Please send your suggestions for new plants to plants@usanpn.org.

What exactly is a USA-NPN calibration species?

A USA-NPN plant calibration species is one of 20 plants selected to help "calibrate" phenological measurements across the USA. These native and introduced plants have broad distributions and are ecologically or economically important. The USA-NPN integrates observations on calibration species to get "the big picture" of plant responses. USA-NPN observers are encouraged to include at least one calibration species in their monitoring projects. Widespread observation of calibration species is needed so that the collective monitoring data for these plants can be integrated with climate measurements across the Nation.

A committee of scientists developed the criteria for calibration species and selected the species. Their list of 20 had widespread review. The criteria for selection were 1) widespread distribution; 2) association with a dominant plant cover type; 3) relationships with other plants and animals; 4) simple identification of species with readily observable phenophases; 5) accessibility to schools and/or population centers; 6) pollinator or wind-borne seed dispersal, and 7) responsiveness to fall as well as spring environmental variables. The species include trees, shrubs, forbs, and grasses. Also, the list represents invasive, allergenic, horticultural, and agricultural species.

See a list of USA-NPN calibration species.

How many individuals of the same species should I monitor?

For most observers, we recommend monitoring between 1 and 3 individuals of the same species at a site. Observers at research sites may wish to choose 3 to 5 individuals per site. Observing multiple individuals helps to give scientists an idea of the variation in phenology among individuals at your site, however, you will need to consider the number of total individuals available and the time you have to monitor in choosing an appropriate number to observe. If you choose to select multiple individuals to monitor, try to select individuals growing in a similar environment (for example, get similar amounts of sun or shade), but that are not direct neighbors and are separated by at least a few plant widths.

Are there other things I should consider when selecting my plant(s)?

Yes, where possible, try to avoid individuals that are closer than 20 feet to a road or building, or plants that are in dense shade most of the day, such as at the north side of a building, or near a cliff or rock outcrop. Also, read the species information for your plant(s) to determine if the species has growth characteristics that might affect your selection of the individuals to monitor. For example, some species grow clonally and form large clumps of stems growing from the same roots. If your plant can be clonal, try to choose individual stems from different clumps. Where it is not possible to follow these guidelines for a specific individual, simply mention that in the comments section when you register that plant.

How can I best mark the plant(s) that I am observing?

For trees and shrubs, flagging tape or small, inconspicuous aluminum tags (obtained from a hardware store or forestry supply company) can be attached to each individual, marked in permanent ink. For grasses and forbs, small pins can be placed next to the individuals that will be observed. Some observers have used colored toothpicks as unobtrusive stakes (sometimes hard to spot as vegetation grows) and loosely tied colored string or small plastic flags around the base of individuals. However you mark the location and individual plants, you will want to make sure that the marking does not change the growing conditions of the plant. For example, avoid placing a broad stake next to a small plant that would shade it or cause root damage. Markers may need to be replaced periodically as they weather and become unreadable.

What if the plant I am observing dies?

If an individual dies or is obviously declining in health (when others of the same species around it are still healthy), you should select a new individual to monitor. However, be sure to note the death in the comments section and to give the replacement a new, unique label. If you are monitoring any annual or biennial species at your site, this procedure will need to be followed regularly since the individual plants die after one and two seasons, respectively.

I requested cloned lilacs but have not received them. What is the status of my request?

We still have more requests for cloned lilac plants than we can immediately satisfy. The number that we can distribute each year is limited by available funds. We are trying to fill requests in a way that will distribute cloned lilacs to all areas across the country, but also send them as soon as possible to those interested in receiving them.

Another option for observers who want to obtain cloned lilacs as quickly as possible, and are willing to help us stretch our limited resources, is to purchase them directly from the supplier, Jung Seed Company. Orders can be placed through Jung’s web page or by calling their order department at 1-800-247-5864.

As a third option, you may purchase a common purple lilac (Syringa vulgaris, usually called "old fashioned" or "hedge") from any nursery and observe it while waiting to get your cloned lilacs. Common purple lilacs make good "partners" with cloned lilacs, as their responses are quite similar."

What type of lilac do I have? Aren't the cloned lilacs you sent me common lilacs?

No. The cloned lilacs you (or a previous observer) received from us (or as part of legacy eastern USA lilac networks) are not commom lilacs! They are Chinese lilacs (Syringa chinensis 'Red Rothomagensis'), which have leaves that are about twice as long as they are wide (much narrower than common purple lilac leaves). As mentioned above, common purple lilacs (Syringa vulgaris, also called "hedge" or "old-fashioned") are those that observers have obtained on their own from nurseries, or already had growing on their grounds. Although these plants are NOT clones, their response is generally quite uniform. Common lilacs have leaves that are somewhat "heart" shaped (much wider than cloned lilac leaves).

How often should I record my observations?

As often as it is convenient for you. Ideally, observations should be recorded at least once a week or even as frequently as every 2 or 3 days, particularly during the spring and fall when plants are changing quickly. But the critical thing is to record observations as often as is convenient for you—your observations, no matter how often you make them, provide valuable data.

Why should I record my observations when nothing has changed since my last observation?

Having a full record of your observation dates allows someone using your data to more confidently narrow down the exact date a phenophase began or ended. For example, if you record that you saw emerging leaves on your April 6 visit, and your last recorded visit was April 2, where you reported you did not see them, we know that phenophase must have began sometime within those 4 to 5 days. If you only record the April 6 visit and no previous visit, we only know that leaves started to emerge sometime between April 6 and the previous winter. This example also illustrates why more frequent observations are useful when a phenophase is expected to begin or end—if you can check every 2 or 3 days, it allows you to provide a more precise estimate of which day a phenophase actually started or ended.

What if I missed a phenophase?

If you miss the occurrence of a phenophase entirely (for example, flowering started and ended while you were away on a 10 day vacation), yet you see evidence that is did indeed happen (such as dried flowers on the ground below the plant), then make a note of this in the comments section for your next observation of that phenophase.

Why is it valuable to know that a phenophase did not occur at all in a given year?

It is not uncommon for some species, especially some trees, not to flower and fruit every year, and information about which years had obvious flowers or fruits and which years did not can be very important to scientists studying the insects and animals that depend on them.

Why should I continue looking for a phenophase even after it has passed?

In some dry climates, phenophases start anew with each rainstorm. Even in temperate regions, where most plant phenophases predictably begin and end only once in a season, climate change may bring substantial changes to the timing of life cycle events which is extremely important to capture! For example, more frequent late frosts or insect defoliation events may cause an increase in multiple episodes of leaf budburst for a given plant species in a single season.

Can I still report 'Emerging leaves/needles/growth' once I see 'Unfolded or Young unfolded leaves/needles' on the plant?

Yes, you should judge each leaf bud, needle bud or shoot separately. As long as some buds or shoots are still opening or emerging and have not yet produced an unfolded leaf or needle, you are seeing emerging leaves, needles or growth on the plant. For plants that have more than one bud or shoot, in most cases you will still be seeing 'Emerging leaves/needles/growth' on some buds or shoots for many days after you first begin seeing 'Unfolded or Young unfolded leaves/needles' on other buds or shoots. It is also possible to see multiple episodes of leaf emergence within a season, while unfolded leaves are still present on the plant. This might occur after a period of severe drought or after an insect defoliation event.

When should I report I no longer see 'Unfolded leaves'?

to be added

How can I judge when a leaf is '≥75% of full leaf size'?

We recognize this will be a rather subjective estimate on the observer's part when there are no mature leaves on the plant for comparision, but just try your best. You could measure full leaf size during summer of the first year and then use that measure to better judge 75% of full leaf size for subsequent years. We are asking observers to note when leaves become 75% of full leaf size in order to create an estimate of the point in time when leaves are almost, but not quite full size. Including this measure in the phenological record for your plant allows scientists to keep track of the length of the "green-up" period (the time is takes leaves to develop to full size), which is an important aspect of a plant's response to climate change.

How do I change data once I have entered it?

If you wish to correct observation data for a particular day, navigate to that day using the arrows below the observation interface. Then change the Yes, No and ? responses to the correct ones for that day. Unfortunately you cannot edit the day for which the observations are reported. If you have correct data entered for the wrong day, then change the wrong day's responses to ?s (didn't check) and add a new day with the correct responses. If you add a comment to the wrong day's submission describing that correction, that will help us keep track of your change.