Lagerstroemia speciosa defoliation stage

Table 4-3 Phenological Observation Records of Trees and Shrubs

Table 4-4 Phenological Observation Records of Herbs

4.2 Plant phenology observation

The rhythm of plant development formed by the long-term adaptation of plants to the rhythmic changes of temperature in a year is called phenology. In the whole growth and development cycle of plants in a year, each growth and development stage is called phenology. Phenology is the reflection of comprehensive meteorological conditions on plants. Using phenology to guide agricultural production and various scientific research activities is more accurate than average temperature, accumulated temperature and season.

Phenological observation is simple and can be carried out anywhere. It is mainly observed by eyes and recorded by hand, without any instruments and equipment. However, the seasonal changes in nature are large-scale, and there is correlation between different regions. At the same time, because there is no need for instrument observation, it is easy to appear deviation, so the observation objects, observation standards and observation methods in different regions must be consistent, otherwise the observation records can not be compared with other regions, which consumes manpower, but can not be widely used.

1. Phenological observation of plant species

The most important problem of phenological observation is to choose the plant species to be observed, so as to coordinate the phenological observation work in the whole country. China has formulated a unified observation type for local observation. Common phenological observation plants in temperate and subtropical regions of China are as follows. 1. pivot

(1) tool holder

oriental arborvitae

Sabina vulgaris ant

dawn redwood

Plus Canadian poplar.

Populus simonii of the genus Populus

weeping willow

Walnut.

Chinese chestnut

Quercus variabilis

elm

Morius albiflora L.

white jade

apple

mountain peach

Peach (Peach)

Prunus armeniaca

Broussonetia papyrus

Albizia julibrissin

Sophora japonica

Robinia pseudoacacia

Jujube, a jujube tree.

Chinese parasol

gingkgo

Ash tree, ash tree.

crape myrtle

Melia azedarach

Luan tree Luan tree

(2) Shrubs

Bauhinia.

Zitengtian

Hibiscus

lilac

2. Vanilla

Chinese herbaceous peony

Chrysanthemum Exoutv。 ) Poems by Ling et al.

Second, the characteristic signs of plant phenology

When observing phenology in all areas, we should work according to the unified phenological characteristics.

1. Trees and shrubs

The phenological periods of trees and shrubs mainly include germination stage, leaf unfolding stage, germination stage, flowering stage, fruit maturity stage, fruit dropping stage, autumn color stage and defoliation stage. The characteristics of each phenological period are as follows.

(1) Germination stage. It can be divided into bud expansion initial stage and bud opening stage.

① The initial stage of bud expansion. Most trees and shrubs have scales in their buds. When the scales of the bud begin to separate on the 1 ~ 2 branchlets of the plant, and the side faces show faint lines or horns, it is the budding stage. Conifers (such as Pinus) have slightly different germination periods. They are the terminal bud scales cracking and rolling back, and the germination period begins when yellow-brown suture appears.

② Bud opening period. When the scales crack, there are scales buds, and green tips appear on the upper part of the buds; When the closed bud obviously grows green leaf bud; When the buds of Pinus plants are elongated into cylinders, they are all signs of entering the bud opening period. For tree species with separate flower buds and leaf buds, the germination periods of the two buds should be recorded separately.

(2) blade opening period. It can be divided into two stages: the beginning of Ye Zhan and the exhibition of Ye Sheng. In its heyday.

(3) the budding stage. When buds or inflorescences appear in the flower buds of 1 ~ 2 branchlets, it is the budding stage.

(4) flowering period. It is divided into initial flowering period, full flowering period and final flowering period.

(1) Flowering. For trees and shrubs pollinated by insects, if the petals of flower buds are completely opened on the 1 ~ 2 twig on the plant, it is the beginning of flowering. Although Salix psammophila is an insect-borne flower, its symbol is different from that of ordinary insect-borne flowers. The sign of its flowering is that the stamens grow on the inflorescence of the male plant. At this time, yellow appears on the sunny side of the inflorescence. When you touch it with your hand, pollen will stick to your fingers. For wind-pollinated trees and shrubs, such as Pinus, Populus, Mulberry, Ulmus, Juglans and Fraxinus, when their branches shake and a small amount of pollen is scattered in the male inflorescence, it is the initial flowering period of these plants.

② Full flowering period. Flowers with 50% branchlets spread their petals or inflorescences with 50% branchlets emit pollen. Enter the full bloom stage.

③ The flowering period is late. For trees and shrubs pollinated by insects, this means that there are only a few flowers left on the plants. For wind-borne trees, it means that the inflorescence stops spreading, or most inflorescences fall off. The symbol of late flowering of Salix is the same as that of wind-borne trees.

(5) Fruit maturity. Because of the diversity of fruit types, the signs of fruit maturity are different. The fruit ripening marks of various fruits are as follows:

① capsules. Such as poplar and willow, the fruit is yellow-green when it is ripe, and a few tips crack, revealing white flocs.

(2) drupes and berries. Some fruits began to soften, showing the unique color and taste of this species.

3 pods. Some fruits began to turn yellow.

④ Samara. The green color of the fruit disappears and becomes yellow or yellowish brown.

The sign of mature conifer seeds means that their cones turn yellow-brown.

(6) Fruit drop period. It can be divided into initial shedding period and final shedding period. When the fruit or seed begins to fall off, it is the beginning of falling off; When almost all the fruits or seeds fall off, it is the end of falling off.

(7) Autumn period. When some leaves start to turn yellow or red, they enter autumn. Coniferous trees are characterized by the yellowing of old needles. The leaf discoloration mentioned here refers to the normal seasonal change, the color of the discolored leaves on the tree no longer disappears, and the newly discolored leaves are increasing day by day. Don't confuse leaf discoloration caused by drought, heat or other reasons in summer, and pay attention to the distinction.

(8) Deciduous period. When the observed trees begin to shed leaves in autumn, they enter the defoliation period, and when almost all the leaves on the trees fall off, the defoliation is over.

2. Phenological characteristics of vegetation and plants

The phenological periods of vegetation mainly include germination period, leaf unfolding period, germination period, flowering period, fruit maturity period, fruit dropping period and yellow withered period. The characteristics of each phenological period are as follows.

(1) Germination stage. Perennial and biennial herbs have aboveground buds and underground buds, and panicum miliaceum seeds have germ. When the ground buds turn green, or underground buds and germs germinate, it is the germination period of herbs.

(2) blade opening period. Leaflets begin to spread on plants, that is, they enter the stage of leaf spreading.

(3) the budding stage. When buds or inflorescences begin to appear, they enter the germination stage.

(4) flowering period. When the petals of individual flowers on plants are fully unfolded for the first time, they enter the flowering period.

(5) Fruit maturity. It can be divided into initial mature stage and complete mature stage. When the fruit on the plant begins to turn into a precocious color, it is the beginning of maturity, and when it is 50% mature, it is completely mature.

(6) Fruit drop period. When the fruit or seed begins to shed, it is the fruit shedding period.

(7) Yellow withered period. It can be divided into early yellow withered period, yellow withered period and total yellow withered period. The basal leaves at the lower part of the plant began to wither, which is the beginning of the withering period; Reaching semi-yellow withered, it is a general yellow withered period; The complete yellow withered period is the complete yellow withered period.

Third, phenological observation methods

Phenological observation in various regions must be carried out in accordance with the following methods.

1. Selected phenological observation point

Before phenological observation, observation points should be selected first. Observation points shall conform to the following two principles.

(1) The site should be stable and can be observed for many years. Because the longer you observe in a fixed place, the more valuable the phenological data you record. Therefore, there is no special reason, it is best not to change the observation site.

(2) The observation site should be representative, with topography, soil and vegetation. Must be considered, and try to choose a flat or quite open place.

After the phenological observation point is selected, the place name, habitat, altitude, topography (flat land, mountain land, concave land, sloping land, etc. ), location (on which side of the building, how far away from the building) and soil properties should be recorded in detail and kept as files.

2. Selected plant species for observation

When observing phenology at an observation point, you don't just observe what plants are. First of all, we should observe common plants according to the phenology of temperate and subtropical regions in China, and choose some of them as observation objects. Then, from the plants in this area, select some plants that can best reflect the local seasonal phenomenon and are closely related to agricultural production as observation objects.

3. Identify the observed plants

As for trees and shrubs, we should choose robust middle-aged trees that have blossomed and borne fruit for more than three years, and choose 3 ~ 5 plants of each species as the observation objects, and observe them in the south direction. Do not harm the selected trees and keep their normal growth and development.

The development period of herbs is closely related to microclimate. In order to avoid the influence of local microclimate, try to choose plants that grow in relatively open places to achieve representativeness. The selected plants should be free of pests and diseases and grow normally. For clustered species, a small piece is selected as the observation object, and for scattered species, dozens of plants close to each other are selected as the observation object, and half of them are used as the spare plants for artificial destruction.

Trees, shrubs and herbs must be planted in the wild or open fields. Do not use potted plants.

4. Phenological observation time

Spring and summer are the period of germination, leaf spreading, flowering and reproduction of various plants, and various phenological phenomena are different every day. It is best to observe it once a day, and if time does not allow, observe it every other day. Autumn can be observed every other day or every three days. In the early winter and late winter, we need to observe, and we can't miss it, but in the middle of winter, there is no need to observe.

5. The observer should be fixed.

Observers should not change from time to time, let alone several people observe in shifts. Because phenology changes all the time, only one person has a connection before and after observation. If you observe in shifts, everyone's understanding of phenological characteristics may be different, so the records before and after will be inconsistent.

6. Make observation records.

Record what you want to see in phenological observation, and don't remember it by memory afterwards.

There are four main forms of phenological observation. See table 4- 1 to 4-4.

Table 4- 1 Records of Geographical Environment of Woody and Herbaceous Plants

Company name: year

[Note] The length of the table can be determined as required, and so can the following table. In order to save space, the original table has been reduced here.

Table 4-2 Daily Phenological Observation Record Table

Phenological observation site year

Among the above four tables, Table 4- 1 records the growing places and geographical environment of various plants after phenological observation plant selection; Table 4-2 is the mode of daily observation record; Tables 4-3 and 4-4 are to sort out and fill in the phenological phenomena of trees, shrubs and herbs recorded in daily observation records. An observation point can fill in a summary table every year.

Fourth, the arrangement of phenological observation data

After two years of phenological observation, the average date of each phenological period should be calculated. The calculation method is to add up the days to get the total, and divide by the number of years to get the average date. If the dates of all the years appear in the same month, the calculation is very simple.