What is forest rodent control?

(Prevention and control of forest rodents)

(Yang Kexing)

Measures and methods to control rodents that steal young tree seedlings, bark or root bark. According to the species and objects of rodents, forest rodents can be divided into two categories. (1) Seeding for afforestation: Because rats steal a lot of seeds, seeding for afforestation does not see seedlings, and no forest can be formed. This kind of mice includes Apodemus giganteus, Apodemus agrarius and chipmunks. The damage period is from sowing to the time when the seedlings are unearthed. (2) Rodents in seedling afforestation (including young forest): Rodents cut off seedlings, nibble on bark and root skin of young trees, or cut off the top and fine roots of side branches, resulting in the failure of seedling afforestation. Do these mice have brown backs? , red back? , swamp vole, northeast zokor, Chinese zokor, gerbil, etc. The main tree species harmful to rats is Pinus sylvestris var. mongolica. Pinus sylvestris var. mongolica, Pinus densiflora, Larix gmelinii, Pinus tabulaeformis, Picea, Tilia amurensis, Cortex Phellodendri, Poplar, Lespedeza, Haloxylon ammodendron and Jujube. The rodent damage of afforestation seedlings mainly occurs within one month after afforestation or in winter; Rodents in young forests mainly occur in winter.

Prediction method of rodent damage

① Prediction method of rodent damage in sowing afforestation: Before afforestation, the number of rodent damage was investigated by daily thread clamping method. If the capture rate of rodents exceeds 2%, appropriate control measures should be taken before or at the same time of sowing. ② Prediction method of rodent damage in seedling-raising afforestation: The prediction method of forest area in Heilongjiang Province is to select 5 ~ 10 sample plots in mid-September every year, and investigate by day-trapping method. According to the trapping rate of rodents, it is divided into four forecast grades: 0 grade, and the trapping rate of rodents is below 3%; Grade ⅰ, the capture rate of rats is 4 ~10%; Grade ⅱ, the rat capture rate was11~ 20%; Grade ⅲ, the capture rate of rats is above 20%. For Grade II and III, reliable prevention and control measures must be taken in time. The prevention and control time of rodent damage in young forest is better in the middle and late September and before the snowfall in the middle and early October of 65438+ 10.

Rodent control method

There are four main forest management technologies, biological control, chemical control and physical control.

Afforestation technology control

According to the biological characteristics of rodents and the main ecological factors that affect the growth and decline of rodents, appropriate forestry technical measures are taken to create environmental conditions that are conducive to the growth of trees and not conducive to the survival of rodents, thus indirectly inhibiting the occurrence of rodents. The main measures are as follows: ① Before direct seeding or planting seedlings for afforestation, the cutting residues on the afforestation land should be cleaned, transported or burned to destroy the hidden environmental conditions of rats; (2) In the peak period of rodent infestation, the weeds and shrubs in the forest are polished and transported out in combination with young forest tending; (3) Rational close planting, strengthening tending, and making young forests close ahead of schedule.

biotic-control

According to the food chain relationship in the forest ecosystem, protect and utilize the natural enemies of rodents, control the growth of rodents and inhibit the occurrence of rodents. There are many kinds of natural enemies of rodents and rich resources. They can kill many rodents every year, which is a positive factor to control the occurrence of rodents, so we must do a good job in protection and utilization. The measures are as follows: ① do a good job in publicity and education to improve the understanding of the importance of protecting natural enemies of rodents. (2) To develop and utilize the precious natural enemy resources, it is necessary to determine the suitable hunting period and hunting quantity, pay attention to maintaining ecological balance and control the occurrence of rodents. Hunting natural enemies of rodents must be prohibited in forest areas where rodents often occur. (3) Create living conditions for rodent natural enemies, increase the number of rodent natural enemies in the plantation and control the occurrence of rodents. For example, some wooden nest boxes with tree holes are hung in the artificial forest to create habitat and breeding conditions for rat-eating birds; Pile up some branches, grass, stones, etc. Create habitat and hidden environmental conditions for weasels in artificial forests. ④ Rodent-eating birds and weasels, such as long-tailed forest owls and weasels, are artificially raised, propagated and domesticated, and then returned to artificial forests to play their rodent control role. There are three main natural enemies of rodents in China forest area: ① Birds: common species are kites, goshawks, hairy feet, grasslands, blackbirds, magpies, white-tailed owls, white-headed owls, kestrels, wedge-tailed shrike, owls, collared owls and long-tailed forest owls. (2) Mammals: the common species are leopard cat, rabbit, red fox, badger, hedgehog, raccoon dog, Yellow weasel, ferret, mongoose, green ferret, lingsha, Ai Hu and sable; ③ Snakes: The common species are Agkistrodon halys, tiger-spotted snakes, grey-chain snakes, pillow-striped snakes and red-spotted snakes. In addition, we can also use specific bacterial viruses (such as plague, typhoid, myxoma virus, etc.). ) and fungal secretions (such as cycloheximide and other rodenticides) to prevent and control rodents.

Chemical control

A method for controlling rodents with drugs with rodenticide activity. Chemical control is effective quickly, and the occurrence of rodent damage can be quickly controlled. However, when it kills rats, it usually kills the natural enemies of rats, which leads to the imbalance of ecological balance and creates conditions for the re-emergence of rats. At the same time, using drugs in large quantities will pollute the environment and cause adverse consequences. Therefore, this method is generally adopted in order to protect young artificial forests from harm or control the development of disasters when tree rodent damage has occurred or is about to occur. The experience of Heilongjiang province in China is that when the number of rodents reaches the second or third grade, chemical control methods are adopted. Chemical control should use rodenticide with high efficiency and low toxicity, and the concentration and dosage per unit area should be appropriate. At present, 5% zinc phosphide bait, 0.2 ~ 0.3% tetramine phosphorus bait or rodenticide pills are mostly used to kill rats in young forests. Put poison bait 0.5 ~ 1 kg per hectare, put poison bait at a row spacing of 5×5 meters, and put 1 ~ 2 g in each pile. In addition, drugs with pungent smell can also be coated on tree trunks or seed dressing to drive away harmful rats. Commonly used are wood tar, sulfur mixture and synthetic pheromone.

Physical prevention and control

In small seed orchards, orchards and nurseries, mousetraps, rat cages and other equipment are used for killing. In addition, you can use an ultrasonic generator or natural enemies to record the chirping sounds to control rats.