2-Maruza Biosfera. Tabiiy resurslar, ulardan oqilona foydalanish va atmosfera muhofazasi. Suv va Tuproq resurslari va uni muhofazasi. O‘simlik, hayvonot dunyosi va ularni muhofaza qilish

 
Differences in Biodiversity
Biodiversity tends to increaseas you move toward the equator because 
temperatures tend tobe warmer. For example, Costa Rica is a Central American countryabout the size 
ofWestVirginia.Yet it is home to as many birdspecies as there are in the United States and Canada 
combined.
Figure 2 
compares mammal biodiversity in three NorthAmerican countries. Ecosystems 
with the highest biodiversity usually have warm, moist climates. In fact, tropical regions containtwo-
thirds of all of Earth‘s land species.
What kind of climate usually has a highbiodiversity?
Why is biodiversity important? 
Would you rather have a summer picnic on a paved parkinglot or on cool grass under a shade tree 
near a stream? Many peoplefind pleasure in nature‘s biodiversity. Perhaps you like tovisit scenic 
areas to hike, swim, relax, or enjoy the views. Manypainters, writers, and musicians find inspiration 
for their workby spending time outdoors. However, beauty and pleasure arenot the only reasons why 
biodiversity is important.
 
Loss of Species
Not everyone agrees about the reason forthe extinction of the dinosaurs. One thing is 
clear—humanactions had nothing to do with it. Dinosaurs were extinct millionsof years before 
humans wereon Earth. Today is different. Therate of extinctions appears to berising. From 1980 to 
2000, close to40 species of plants and animals inthe United States became extinct. Itis estimated that 
hundreds, if notthousands, of tropical speciesbecame extinct during the same20-year period. Human 
activitiesprobably contributed to most ofthese extinctions. As the humanpopulation grows, many 
morespecies could be lost.
 
1
Peter Rillero, Dinah Zike Ecology, 2005. (126-127; 129- bet) 
Nazorat va mulohaza uchun savollar. 
1. O„simliklar dunyosi
tabiatda qanday ahamiyatga ega? 
2. Yer yuzida qancha tur o‗simliklar bor? 
3. 
O„zbekiston o„simliklar dunyosi
da qancha o‗simliklar turi mavjud? 
4. 
“Qizil kitob”
haqida fikr yuriting. 
5. O‗zbekistonda o‗simliklarni muhofaza qilish borasida davlatimiz tomonidan qanday 
ishlar olib borilmoqda?