Deforestation can be defined as the loss of forests due to the impact of human activities or natural causes.
Some of the negative consequences of deforestation are the loss of the habitat of native species in the area that was deforested, this puts the lives of these species at risk.
Another consequence is that deforestation promotes global warming, since forests and jungles help to consume a considerable part of atmospheric CO2, reducing environmental pollution and therefore, the amount of greenhouse gases, also decreasing environmental temperature.
Regarding the positive effects of deforestation, these would be mostly economic, since the wood of the trees works as a raw material for many materials that are currently used. While environmentally the advantages are scarce. An example could be the logging of invasive species in an ecosystem (if they exist). However, deforestation is normally carried out indiscriminately, so it would also affect native species